C/C++ - Silent Stepper Brick

This is the description of the C/C++ API bindings for the Silent Stepper Brick. General information and technical specifications for the Silent Stepper Brick are summarized in its hardware description.

An installation guide for the C/C++ API bindings is part of their general description.

Examples

The example code below is Public Domain (CC0 1.0).

Configuration

Download (example_configuration.c)

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#include <stdio.h>

#include "ip_connection.h"
#include "brick_silent_stepper.h"

#define HOST "localhost"
#define PORT 4223
#define UID "XXYYZZ" // Change XXYYZZ to the UID of your Silent Stepper Brick

int main(void) {
    // Create IP connection
    IPConnection ipcon;
    ipcon_create(&ipcon);

    // Create device object
    SilentStepper ss;
    silent_stepper_create(&ss, UID, &ipcon);

    // Connect to brickd
    if(ipcon_connect(&ipcon, HOST, PORT) < 0) {
        fprintf(stderr, "Could not connect\n");
        return 1;
    }
    // Don't use device before ipcon is connected

    silent_stepper_set_motor_current(&ss, 800); // 800mA
    silent_stepper_set_step_configuration(&ss, SILENT_STEPPER_STEP_RESOLUTION_8,
                                          true); // 1/8 steps (interpolated)
    silent_stepper_set_max_velocity(&ss, 2000); // Velocity 2000 steps/s

    // Slow acceleration (500 steps/s^2),
    // Fast deacceleration (5000 steps/s^2)
    silent_stepper_set_speed_ramping(&ss, 500, 5000);

    silent_stepper_enable(&ss); // Enable motor power
    silent_stepper_set_steps(&ss, 60000); // Drive 60000 steps forward

    printf("Press key to exit\n");
    getchar();
    silent_stepper_disable(&ss);
    silent_stepper_destroy(&ss);
    ipcon_destroy(&ipcon); // Calls ipcon_disconnect internally
    return 0;
}

Callback

Download (example_callback.c)

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#include <stdio.h>

#include "ip_connection.h"
#include "brick_silent_stepper.h"

#define HOST "localhost"
#define PORT 4223
#define UID "XXYYZZ" // Change XXYYZZ to the UID of your Silent Stepper Brick

// Use position reached callback to program random movement
void cb_position_reached(int32_t position, void *user_data) {
    (void)position; // avoid unused parameter warning

    SilentStepper *ss = (SilentStepper *)user_data;
    int32_t steps;

    if(rand() % 2) {
        steps = (rand() % 4000) + 1000; // steps (forward)
        printf("Driving forward: %d steps\n", steps);
    } else {
        steps = -((rand() % 4000) + 1000); // steps (backward)
        printf("Driving backward: %d steps\n", steps);
    }

    int16_t vel = (rand() % 1800) + 200; // steps/s
    uint16_t acc = (rand() % 900) + 100; // steps/s^2
    uint16_t dec = (rand() % 900) + 100; // steps/s^2

    printf("Configuration (vel, acc, dec): %d, %d %d\n", vel, acc, dec);

    silent_stepper_set_speed_ramping(ss, acc, dec);
    silent_stepper_set_max_velocity(ss, vel);
    silent_stepper_set_steps(ss, steps);
}

int main(void) {
    // Create IP connection
    IPConnection ipcon;
    ipcon_create(&ipcon);

    // Create device object
    SilentStepper ss;
    silent_stepper_create(&ss, UID, &ipcon);

    // Connect to brickd
    if(ipcon_connect(&ipcon, HOST, PORT) < 0) {
        fprintf(stderr, "Could not connect\n");
        return 1;
    }
    // Don't use device before ipcon is connected

    // Register position reached callback to function cb_position_reached
    silent_stepper_register_callback(&ss,
                                     SILENT_STEPPER_CALLBACK_POSITION_REACHED,
                                     (void *)cb_position_reached,
                                     NULL);

    silent_stepper_set_step_configuration(&ss, SILENT_STEPPER_STEP_RESOLUTION_8,
                                          true); // 1/8 steps (interpolated)
    silent_stepper_enable(&ss); // Enable motor power
    silent_stepper_set_steps(&ss, 1); // Drive one step forward to get things going

    printf("Press key to exit\n");
    getchar();
    silent_stepper_disable(&ss);
    silent_stepper_destroy(&ss);
    ipcon_destroy(&ipcon); // Calls ipcon_disconnect internally
    return 0;
}

API

Every function of the C/C++ bindings returns an integer which describes an error code. Data returned from the device, when a getter is called, is handled via call by reference. These parameters are labeled with the ret_ prefix.

Possible error codes are:

  • E_OK = 0
  • E_TIMEOUT = -1
  • E_NO_STREAM_SOCKET = -2
  • E_HOSTNAME_INVALID = -3
  • E_NO_CONNECT = -4
  • E_NO_THREAD = -5
  • E_NOT_ADDED = -6 (unused since bindings version 2.0.0)
  • E_ALREADY_CONNECTED = -7
  • E_NOT_CONNECTED = -8
  • E_INVALID_PARAMETER = -9
  • E_NOT_SUPPORTED = -10
  • E_UNKNOWN_ERROR_CODE = -11
  • E_STREAM_OUT_OF_SYNC = -12

as defined in ip_connection.h.

All functions listed below are thread-safe.

Basic Functions

void silent_stepper_create(SilentStepper *silent_stepper, const char *uid, IPConnection *ipcon)

Creates the device object silent_stepper with the unique device ID uid and adds it to the IPConnection ipcon:

SilentStepper silent_stepper;
silent_stepper_create(&silent_stepper, "YOUR_DEVICE_UID", &ipcon);

This device object can be used after the IP connection has been connected (see examples above).

void silent_stepper_destroy(SilentStepper *silent_stepper)

Removes the device object silent_stepper from its IPConnection and destroys it. The device object cannot be used anymore afterwards.

int silent_stepper_set_max_velocity(SilentStepper *silent_stepper, uint16_t velocity)

Sets the maximum velocity of the stepper motor in steps per second. This function does not start the motor, it merely sets the maximum velocity the stepper motor is accelerated to. To get the motor running use either silent_stepper_set_target_position(), silent_stepper_set_steps(), silent_stepper_drive_forward() or silent_stepper_drive_backward().

int silent_stepper_get_max_velocity(SilentStepper *silent_stepper, uint16_t *ret_velocity)

Returns the velocity as set by silent_stepper_set_max_velocity().

int silent_stepper_get_current_velocity(SilentStepper *silent_stepper, uint16_t *ret_velocity)

Returns the current velocity of the stepper motor in steps per second.

int silent_stepper_set_speed_ramping(SilentStepper *silent_stepper, uint16_t acceleration, uint16_t deacceleration)

Sets the acceleration and deacceleration of the stepper motor. The values are given in steps/s². An acceleration of 1000 means, that every second the velocity is increased by 1000 steps/s.

For example: If the current velocity is 0 and you want to accelerate to a velocity of 8000 steps/s in 10 seconds, you should set an acceleration of 800 steps/s².

An acceleration/deacceleration of 0 means instantaneous acceleration/deacceleration (not recommended)

The default value is 1000 for both

int silent_stepper_get_speed_ramping(SilentStepper *silent_stepper, uint16_t *ret_acceleration, uint16_t *ret_deacceleration)

Returns the acceleration and deacceleration as set by silent_stepper_set_speed_ramping().

int silent_stepper_full_brake(SilentStepper *silent_stepper)

Executes an active full brake.

Warning

This function is for emergency purposes, where an immediate brake is necessary. Depending on the current velocity and the strength of the motor, a full brake can be quite violent.

Call silent_stepper_stop() if you just want to stop the motor.

int silent_stepper_set_steps(SilentStepper *silent_stepper, int32_t steps)

Sets the number of steps the stepper motor should run. Positive values will drive the motor forward and negative values backward. The velocity, acceleration and deacceleration as set by silent_stepper_set_max_velocity() and silent_stepper_set_speed_ramping() will be used.

int silent_stepper_get_steps(SilentStepper *silent_stepper, int32_t *ret_steps)

Returns the last steps as set by silent_stepper_set_steps().

int silent_stepper_get_remaining_steps(SilentStepper *silent_stepper, int32_t *ret_steps)

Returns the remaining steps of the last call of silent_stepper_set_steps(). For example, if silent_stepper_set_steps() is called with 2000 and silent_stepper_get_remaining_steps() is called after the motor has run for 500 steps, it will return 1500.

int silent_stepper_drive_forward(SilentStepper *silent_stepper)

Drives the stepper motor forward until silent_stepper_drive_backward() or silent_stepper_stop() is called. The velocity, acceleration and deacceleration as set by silent_stepper_set_max_velocity() and silent_stepper_set_speed_ramping() will be used.

int silent_stepper_drive_backward(SilentStepper *silent_stepper)

Drives the stepper motor backward until silent_stepper_drive_forward() or silent_stepper_stop() is triggered. The velocity, acceleration and deacceleration as set by silent_stepper_set_max_velocity() and silent_stepper_set_speed_ramping() will be used.

int silent_stepper_stop(SilentStepper *silent_stepper)

Stops the stepper motor with the deacceleration as set by silent_stepper_set_speed_ramping().

int silent_stepper_set_motor_current(SilentStepper *silent_stepper, uint16_t current)

Sets the current in mA with which the motor will be driven. The minimum value is 360mA, the maximum value 1640mA and the default value is 800mA.

Warning

Do not set this value above the specifications of your stepper motor. Otherwise it may damage your motor.

int silent_stepper_get_motor_current(SilentStepper *silent_stepper, uint16_t *ret_current)

Returns the current as set by silent_stepper_set_motor_current().

int silent_stepper_enable(SilentStepper *silent_stepper)

Enables the driver chip. The driver parameters can be configured (maximum velocity, acceleration, etc) before it is enabled.

int silent_stepper_disable(SilentStepper *silent_stepper)

Disables the driver chip. The configurations are kept (maximum velocity, acceleration, etc) but the motor is not driven until it is enabled again.

int silent_stepper_is_enabled(SilentStepper *silent_stepper, bool *ret_enabled)

Returns true if the driver chip is enabled, false otherwise.

int silent_stepper_set_basic_configuration(SilentStepper *silent_stepper, uint16_t standstill_current, uint16_t motor_run_current, uint16_t standstill_delay_time, uint16_t power_down_time, uint16_t stealth_threshold, uint16_t coolstep_threshold, uint16_t classic_threshold, bool high_velocity_chopper_mode)

Sets the basic configuration parameters for the different modes (Stealth, Coolstep, Classic).

  • Standstill Current: This value can be used to lower the current during stand still. This might be reasonable to reduce the heating of the motor and the Brick. When the motor is in standstill the configured motor phase current will be driven until the configured Power Down Time is elapsed. After that the phase current will be reduced to the standstill current. The elapsed time for this reduction can be configured with the Standstill Delay Time. The unit is in mA and the maximum allowed value is the configured maximum motor current (see silent_stepper_set_motor_current()).
  • Motor Run Current: The value sets the motor current when the motor is running. Use a value of at least one half of the global maximum motor current for a good microstep performance. The unit is in mA and the maximum allowed value is the current motor current. The API maps the entered value to 1/32 ... 32/32 of the maximum motor current. This value should be used to change the motor current during motor movement, whereas the global maximum motor current should not be changed while the motor is moving (see silent_stepper_set_motor_current()).
  • Standstill Delay Time: Controls the duration for motor power down after a motion as soon as standstill is detected and the Power Down Time is expired. A high Standstill Delay Time results in a smooth transition that avoids motor jerk during power down. The value range is 0 to 307ms
  • Power Down Time: Sets the delay time after a stand still. The value range is 0 to 5222ms.
  • Stealth Threshold: Sets the upper threshold for Stealth mode in steps/s. The value range is 0-65536 steps/s. If the velocity of the motor goes above this value, Stealth mode is turned off. Otherwise it is turned on. In Stealth mode the torque declines with high speed.
  • Coolstep Threshold: Sets the lower threshold for Coolstep mode in steps/s. The value range is 0-65536 steps/s. The Coolstep Threshold needs to be above the Stealth Threshold.
  • Classic Threshold: Sets the lower threshold for classic mode. The value range is 0-65536 steps/s. In classic mode the stepper becomes more noisy, but the torque is maximized.
  • High Velocity Shopper Mode: If High Velocity Shopper Mode is enabled, the stepper control is optimized to run the stepper motors at high velocities.

If you want to use all three thresholds make sure that Stealth Threshold < Coolstep Threshold < Classic Threshold.

The default values are:

  • Standstill Current: 200
  • Motor Run Current: 800
  • Standstill Delay Time: 0
  • Power Down Time: 1000
  • Stealth Threshold: 500
  • Coolstep Threshold: 500
  • Classic Threshold: 1000
  • High Velocity Shopper Mode: false
int silent_stepper_get_basic_configuration(SilentStepper *silent_stepper, uint16_t *ret_standstill_current, uint16_t *ret_motor_run_current, uint16_t *ret_standstill_delay_time, uint16_t *ret_power_down_time, uint16_t *ret_stealth_threshold, uint16_t *ret_coolstep_threshold, uint16_t *ret_classic_threshold, bool *ret_high_velocity_chopper_mode)

Returns the configuration as set by silent_stepper_set_basic_configuration().

Advanced Functions

int silent_stepper_set_current_position(SilentStepper *silent_stepper, int32_t position)

Sets the current steps of the internal step counter. This can be used to set the current position to 0 when some kind of starting position is reached (e.g. when a CNC machine reaches a corner).

int silent_stepper_get_current_position(SilentStepper *silent_stepper, int32_t *ret_position)

Returns the current position of the stepper motor in steps. On startup the position is 0. The steps are counted with all possible driving functions (silent_stepper_set_target_position(), silent_stepper_set_steps(), silent_stepper_drive_forward() or silent_stepper_drive_backward()). It also is possible to reset the steps to 0 or set them to any other desired value with silent_stepper_set_current_position().

int silent_stepper_set_target_position(SilentStepper *silent_stepper, int32_t position)

Sets the target position of the stepper motor in steps. For example, if the current position of the motor is 500 and silent_stepper_set_target_position() is called with 1000, the stepper motor will drive 500 steps forward. It will use the velocity, acceleration and deacceleration as set by silent_stepper_set_max_velocity() and silent_stepper_set_speed_ramping().

A call of silent_stepper_set_target_position() with the parameter x is equivalent to a call of silent_stepper_set_steps() with the parameter (x - silent_stepper_get_current_position()).

int silent_stepper_get_target_position(SilentStepper *silent_stepper, int32_t *ret_position)

Returns the last target position as set by silent_stepper_set_target_position().

int silent_stepper_set_step_configuration(SilentStepper *silent_stepper, uint8_t step_resolution, bool interpolation)

Sets the step resolution from full-step up to 1/256-step.

If interpolation is turned on, the Silent Stepper Brick will always interpolate your step inputs as 1/256-step. If you use full-step mode with interpolation, each step will generate 256 1/256 steps.

For maximum torque use full-step without interpolation. For maximum resolution use 1/256-step. Turn interpolation on to make the Stepper driving less noisy.

If you often change the speed with high acceleration you should turn the interpolation off.

The default is 1/256-step with interpolation on.

The following defines are available for this function:

  • SILENT_STEPPER_STEP_RESOLUTION_1 = 8
  • SILENT_STEPPER_STEP_RESOLUTION_2 = 7
  • SILENT_STEPPER_STEP_RESOLUTION_4 = 6
  • SILENT_STEPPER_STEP_RESOLUTION_8 = 5
  • SILENT_STEPPER_STEP_RESOLUTION_16 = 4
  • SILENT_STEPPER_STEP_RESOLUTION_32 = 3
  • SILENT_STEPPER_STEP_RESOLUTION_64 = 2
  • SILENT_STEPPER_STEP_RESOLUTION_128 = 1
  • SILENT_STEPPER_STEP_RESOLUTION_256 = 0
int silent_stepper_get_step_configuration(SilentStepper *silent_stepper, uint8_t *ret_step_resolution, bool *ret_interpolation)

Returns the step mode as set by silent_stepper_set_step_configuration().

The following defines are available for this function:

  • SILENT_STEPPER_STEP_RESOLUTION_1 = 8
  • SILENT_STEPPER_STEP_RESOLUTION_2 = 7
  • SILENT_STEPPER_STEP_RESOLUTION_4 = 6
  • SILENT_STEPPER_STEP_RESOLUTION_8 = 5
  • SILENT_STEPPER_STEP_RESOLUTION_16 = 4
  • SILENT_STEPPER_STEP_RESOLUTION_32 = 3
  • SILENT_STEPPER_STEP_RESOLUTION_64 = 2
  • SILENT_STEPPER_STEP_RESOLUTION_128 = 1
  • SILENT_STEPPER_STEP_RESOLUTION_256 = 0
int silent_stepper_get_stack_input_voltage(SilentStepper *silent_stepper, uint16_t *ret_voltage)

Returns the stack input voltage in mV. The stack input voltage is the voltage that is supplied via the stack, i.e. it is given by a Step-Down or Step-Up Power Supply.

int silent_stepper_get_external_input_voltage(SilentStepper *silent_stepper, uint16_t *ret_voltage)

Returns the external input voltage in mV. The external input voltage is given via the black power input connector on the Slient Stepper Brick.

If there is an external input voltage and a stack input voltage, the motor will be driven by the external input voltage. If there is only a stack voltage present, the motor will be driven by this voltage.

Warning

This means, if you have a high stack voltage and a low external voltage, the motor will be driven with the low external voltage. If you then remove the external connection, it will immediately be driven by the high stack voltage

int silent_stepper_set_spreadcycle_configuration(SilentStepper *silent_stepper, uint8_t slow_decay_duration, bool enable_random_slow_decay, uint8_t fast_decay_duration, uint8_t hysteresis_start_value, int8_t hysteresis_end_value, int8_t sine_wave_offset, uint8_t chopper_mode, uint8_t comparator_blank_time, bool fast_decay_without_comparator)

Note: If you don't know what any of this means you can very likely keep all of the values as default!

Sets the Spreadcycle configuration parameters. Spreadcycle is a chopper algorithm which actively controls the motor current flow. More information can be found in the TMC2130 datasheet on page 47 (7 spreadCycle and Classic Chopper).

  • Slow Decay Duration: Controls duration of off time setting of slow decay phase. The value range is 0-15. 0 = driver disabled, all bridges off. Use 1 only with Comparator Blank time >= 2.

  • Enable Random Slow Decay: Set to false to fix chopper off time as set by Slow Decay Duration. If you set it to true, Decay Duration is randomly modulated.

  • Fast Decay Duration: Sets the fast decay duration. The value range is 0-15. This parameters is only used if the Chopper Mode is set to Fast Decay.

  • Hysteresis Start Value: Sets the hysteresis start value. The value range is 0-7. This parameter is only used if the Chopper Mode is set to Spread Cycle.

  • Hysteresis End Value: Sets the hysteresis end value. The value range is -3 to 12. This parameter is only used if the Chopper Mode is set to Spread Cycle.

  • Sine Wave Offset: Sets the sine wave offset. The value range is -3 to 12. This parameters is only used if the Chopper Mode is set to Fast Decay. 1/512 of the value becomes added to the absolute value of the sine wave.

  • Chopper Mode: 0 = Spread Cycle, 1 = Fast Decay.

  • Comparator Blank Time: Sets the blank time of the comparator. Available values are

    • 0 = 16 clocks,
    • 1 = 24 clocks,
    • 2 = 36 clocks and
    • 3 = 54 clocks.

    A value of 1 or 2 is recommended for most applications.

  • Fast Decay Without Comparator: If set to true the current comparator usage for termination of the fast decay cycle is disabled.

The default values are:

  • Slow Decay Duration: 4
  • Enable Random Slow Decay: 0
  • Fast Decay Duration: 0
  • Hysteresis Start Value: 0
  • Hysteresis End Value: 0
  • Sine Wave Offset: 0
  • Chopper Mode: 0
  • Comparator Blank Time: 1
  • Fast Decay Without Comparator: false

The following defines are available for this function:

  • SILENT_STEPPER_CHOPPER_MODE_SPREAD_CYCLE = 0
  • SILENT_STEPPER_CHOPPER_MODE_FAST_DECAY = 1
int silent_stepper_get_spreadcycle_configuration(SilentStepper *silent_stepper, uint8_t *ret_slow_decay_duration, bool *ret_enable_random_slow_decay, uint8_t *ret_fast_decay_duration, uint8_t *ret_hysteresis_start_value, int8_t *ret_hysteresis_end_value, int8_t *ret_sine_wave_offset, uint8_t *ret_chopper_mode, uint8_t *ret_comparator_blank_time, bool *ret_fast_decay_without_comparator)

Returns the configuration as set by silent_stepper_set_basic_configuration().

The following defines are available for this function:

  • SILENT_STEPPER_CHOPPER_MODE_SPREAD_CYCLE = 0
  • SILENT_STEPPER_CHOPPER_MODE_FAST_DECAY = 1
int silent_stepper_set_stealth_configuration(SilentStepper *silent_stepper, bool enable_stealth, uint8_t amplitude, uint8_t gradient, bool enable_autoscale, bool force_symmetric, uint8_t freewheel_mode)

Note: If you don't know what any of this means you can very likely keep all of the values as default!

Sets the configuration relevant for Stealth mode.

  • Enable Stealth: If set to true the stealth mode is enabled, if set to false the stealth mode is disabled, even if the speed is below the threshold set in silent_stepper_set_basic_configuration().
  • Amplitude: If autoscale is disabled, the PWM amplitude is scaled by this value. If autoscale is enabled, this value defines the maximum PWM amplitude change per half wave. The value range is 0-255.
  • Gradient: If autoscale is disabled, the PWM gradient is scaled by this value. If autoscale is enabled, this value defines the maximum PWM gradient. With autoscale a value above 64 is recommended, otherwise the regulation might not be able to measure the current. The value range is 0-255.
  • Enable Autoscale: If set to true, automatic current control is used. Otherwise the user defined amplitude and gradient are used.
  • Force Symmetric: If true, A symmetric PWM cycle is enforced. Otherwise the PWM value may change within each PWM cycle.
  • Freewheel Mode: The freewheel mode defines the behavior in stand still if the Standstill Current (see silent_stepper_set_basic_configuration()) is set to 0.

The default values are:

  • Enable Stealth: true
  • Amplitude: 128
  • Gradient: 4
  • Enable Autoscale: true
  • Force Symmetric: false
  • Freewheel Mode: 0 (Normal)

The following defines are available for this function:

  • SILENT_STEPPER_FREEWHEEL_MODE_NORMAL = 0
  • SILENT_STEPPER_FREEWHEEL_MODE_FREEWHEELING = 1
  • SILENT_STEPPER_FREEWHEEL_MODE_COIL_SHORT_LS = 2
  • SILENT_STEPPER_FREEWHEEL_MODE_COIL_SHORT_HS = 3
int silent_stepper_get_stealth_configuration(SilentStepper *silent_stepper, bool *ret_enable_stealth, uint8_t *ret_amplitude, uint8_t *ret_gradient, bool *ret_enable_autoscale, bool *ret_force_symmetric, uint8_t *ret_freewheel_mode)

Returns the configuration as set by silent_stepper_set_stealth_configuration().

The following defines are available for this function:

  • SILENT_STEPPER_FREEWHEEL_MODE_NORMAL = 0
  • SILENT_STEPPER_FREEWHEEL_MODE_FREEWHEELING = 1
  • SILENT_STEPPER_FREEWHEEL_MODE_COIL_SHORT_LS = 2
  • SILENT_STEPPER_FREEWHEEL_MODE_COIL_SHORT_HS = 3
int silent_stepper_set_coolstep_configuration(SilentStepper *silent_stepper, uint8_t minimum_stallguard_value, uint8_t maximum_stallguard_value, uint8_t current_up_step_width, uint8_t current_down_step_width, uint8_t minimum_current, int8_t stallguard_threshold_value, uint8_t stallguard_mode)

Note: If you don't know what any of this means you can very likely keep all of the values as default!

Sets the configuration relevant for Coolstep.

  • Minimum Stallguard Value: If the Stallguard result falls below this value*32, the motor current is increased to reduce motor load angle. The value range is 0-15. A value of 0 turns Coolstep off.
  • Maximum Stallguard Value: If the Stallguard result goes above (Min Stallguard Value + Max Stallguard Value + 1) * 32, the motor current is decreased to save energy.
  • Current Up Step Width: Sets the up step increment per Stallguard value. The value range is 0-3, corresponding to the increments 1, 2, 4 and 8.
  • Current Down Step Width: Sets the down step decrement per Stallguard value. The value range is 0-3, corresponding to the decrements 1, 2, 8 and 16.
  • Minimum Current: Sets the minimum current for Coolstep current control. You can choose between half and quarter of the run current.
  • Stallguard Threshold Value: Sets the level for stall output (see silent_stepper_get_driver_status()). The value range is -64 to +63. A lower value gives a higher sensitivity. You have to find a suitable value for your motor by trial and error, 0 works for most motors.
  • Stallguard Mode: Set to 0 for standard resolution or 1 for filtered mode. In filtered mode the Stallguard signal will be updated every four full-steps.

The default values are:

  • Minimum Stallguard Value: 2
  • Maximum Stallguard Value: 10
  • Current Up Step Width: 0
  • Current Down Step Width: 0
  • Minimum Current: 0
  • Stallguard Threshold Value: 0
  • Stallguard Mode: 0

The following defines are available for this function:

  • SILENT_STEPPER_CURRENT_UP_STEP_INCREMENT_1 = 0
  • SILENT_STEPPER_CURRENT_UP_STEP_INCREMENT_2 = 1
  • SILENT_STEPPER_CURRENT_UP_STEP_INCREMENT_4 = 2
  • SILENT_STEPPER_CURRENT_UP_STEP_INCREMENT_8 = 3
  • SILENT_STEPPER_CURRENT_DOWN_STEP_DECREMENT_1 = 0
  • SILENT_STEPPER_CURRENT_DOWN_STEP_DECREMENT_2 = 1
  • SILENT_STEPPER_CURRENT_DOWN_STEP_DECREMENT_8 = 2
  • SILENT_STEPPER_CURRENT_DOWN_STEP_DECREMENT_32 = 3
  • SILENT_STEPPER_MINIMUM_CURRENT_HALF = 0
  • SILENT_STEPPER_MINIMUM_CURRENT_QUARTER = 1
  • SILENT_STEPPER_STALLGUARD_MODE_STANDARD = 0
  • SILENT_STEPPER_STALLGUARD_MODE_FILTERED = 1
int silent_stepper_get_coolstep_configuration(SilentStepper *silent_stepper, uint8_t *ret_minimum_stallguard_value, uint8_t *ret_maximum_stallguard_value, uint8_t *ret_current_up_step_width, uint8_t *ret_current_down_step_width, uint8_t *ret_minimum_current, int8_t *ret_stallguard_threshold_value, uint8_t *ret_stallguard_mode)

Returns the configuration as set by silent_stepper_set_coolstep_configuration().

The following defines are available for this function:

  • SILENT_STEPPER_CURRENT_UP_STEP_INCREMENT_1 = 0
  • SILENT_STEPPER_CURRENT_UP_STEP_INCREMENT_2 = 1
  • SILENT_STEPPER_CURRENT_UP_STEP_INCREMENT_4 = 2
  • SILENT_STEPPER_CURRENT_UP_STEP_INCREMENT_8 = 3
  • SILENT_STEPPER_CURRENT_DOWN_STEP_DECREMENT_1 = 0
  • SILENT_STEPPER_CURRENT_DOWN_STEP_DECREMENT_2 = 1
  • SILENT_STEPPER_CURRENT_DOWN_STEP_DECREMENT_8 = 2
  • SILENT_STEPPER_CURRENT_DOWN_STEP_DECREMENT_32 = 3
  • SILENT_STEPPER_MINIMUM_CURRENT_HALF = 0
  • SILENT_STEPPER_MINIMUM_CURRENT_QUARTER = 1
  • SILENT_STEPPER_STALLGUARD_MODE_STANDARD = 0
  • SILENT_STEPPER_STALLGUARD_MODE_FILTERED = 1
int silent_stepper_set_misc_configuration(SilentStepper *silent_stepper, bool disable_short_to_ground_protection, uint8_t synchronize_phase_frequency)

Note: If you don't know what any of this means you can very likely keep all of the values as default!

Sets miscellaneous configuration parameters.

  • Disable Short To Ground Protection: Set to false to enable short to ground protection, otherwise it is disabled.
  • Synchronize Phase Frequency: With this parameter you can synchronize the chopper for both phases of a two phase motor to avoid the occurrence of a beat. The value range is 0-15. If set to 0, the synchronization is turned off. Otherwise the synchronization is done through the formula f_sync = f_clk/(value*64). In Classic Mode the synchronization is automatically switched off. f_clk is 12.8MHz.

The default values are:

  • Disable Short To Ground Protection: 0
  • Synchronize Phase Frequency: 0
int silent_stepper_get_misc_configuration(SilentStepper *silent_stepper, bool *ret_disable_short_to_ground_protection, uint8_t *ret_synchronize_phase_frequency)

Returns the configuration as set by silent_stepper_set_misc_configuration().

int silent_stepper_get_driver_status(SilentStepper *silent_stepper, uint8_t *ret_open_load, uint8_t *ret_short_to_ground, uint8_t *ret_over_temperature, bool *ret_motor_stalled, uint8_t *ret_actual_motor_current, bool *ret_full_step_active, uint8_t *ret_stallguard_result, uint8_t *ret_stealth_voltage_amplitude)

Returns the current driver status.

  • Open Load: Indicates if an open load is present on phase A, B or both. This could mean that there is a problem with the wiring of the motor. False detection can occur in fast motion as well as during stand still.
  • Short To Ground: Indicates if a short to ground is present on phase A, B or both. If this is detected the driver automatically becomes disabled and stays disabled until it is enabled again manually.
  • Over Temperature: The over temperature indicator switches to "Warning" if the driver IC warms up. The warning flag is expected during long duration stepper uses. If the temperature limit is reached the indicator switches to "Limit". In this case the driver becomes disabled until it cools down again.
  • Motor Stalled: Is true if a motor stall was detected.
  • Actual Motor Current: Indicates the actual current control scaling as used in Coolstep mode. The returned value is between 0 and 31. It represents a multiplier of 1/32 to 32/32 of the Motor Run Current as set by silent_stepper_set_basic_configuration(). Example: If a Motor Run Current of 1000mA was set and the returned value is 15, the Actual Motor Current is 16/32*1000mA = 500mA.
  • Stallguard Result: Indicates the load of the motor. A lower value signals a higher load. Per trial and error you can find out which value corresponds to a suitable torque for the velocity used in your application. After that you can use this threshold value to find out if a motor stall becomes probable and react on it (e.g. decrease velocity). During stand still this value can not be used for stall detection, it shows the chopper on-time for motor coil A.
  • Stealth Voltage Amplitude: Shows the actual PWM scaling. In Stealth mode it can be used to detect motor load and stall if autoscale is enabled (see silent_stepper_set_stealth_configuration()).

The following defines are available for this function:

  • SILENT_STEPPER_OPEN_LOAD_NONE = 0
  • SILENT_STEPPER_OPEN_LOAD_PHASE_A = 1
  • SILENT_STEPPER_OPEN_LOAD_PHASE_B = 2
  • SILENT_STEPPER_OPEN_LOAD_PHASE_AB = 3
  • SILENT_STEPPER_SHORT_TO_GROUND_NONE = 0
  • SILENT_STEPPER_SHORT_TO_GROUND_PHASE_A = 1
  • SILENT_STEPPER_SHORT_TO_GROUND_PHASE_B = 2
  • SILENT_STEPPER_SHORT_TO_GROUND_PHASE_AB = 3
  • SILENT_STEPPER_OVER_TEMPERATURE_NONE = 0
  • SILENT_STEPPER_OVER_TEMPERATURE_WARNING = 1
  • SILENT_STEPPER_OVER_TEMPERATURE_LIMIT = 2
int silent_stepper_set_time_base(SilentStepper *silent_stepper, uint32_t time_base)

Sets the time base of the velocity and the acceleration of the Silent Stepper Brick (in seconds).

For example, if you want to make one step every 1.5 seconds, you can set the time base to 15 and the velocity to 10. Now the velocity is 10steps/15s = 1steps/1.5s.

The default value is 1.

int silent_stepper_get_time_base(SilentStepper *silent_stepper, uint32_t *ret_time_base)

Returns the time base as set by silent_stepper_set_time_base().

int silent_stepper_get_all_data(SilentStepper *silent_stepper, uint16_t *ret_current_velocity, int32_t *ret_current_position, int32_t *ret_remaining_steps, uint16_t *ret_stack_voltage, uint16_t *ret_external_voltage, uint16_t *ret_current_consumption)

Returns the following parameters: The current velocity, the current position, the remaining steps, the stack voltage, the external voltage and the current consumption of the stepper motor.

The current consumption is calculated by multiplying the Actual Motor Current value (see silent_stepper_set_basic_configuration()) with the Motor Run Current (see silent_stepper_get_driver_status()). This is an internal calculation of the driver, not an independent external measurement.

The current consumption calculation was broken up to firmware 2.0.1, it is fixed since firmware 2.0.2.

There is also a callback for this function, see SILENT_STEPPER_CALLBACK_ALL_DATA callback.

int silent_stepper_get_api_version(SilentStepper *silent_stepper, uint8_t ret_api_version[3])

Returns the version of the API definition (major, minor, revision) implemented by this API bindings. This is neither the release version of this API bindings nor does it tell you anything about the represented Brick or Bricklet.

int silent_stepper_get_response_expected(SilentStepper *silent_stepper, uint8_t function_id, bool *ret_response_expected)

Returns the response expected flag for the function specified by the function ID parameter. It is true if the function is expected to send a response, false otherwise.

For getter functions this is enabled by default and cannot be disabled, because those functions will always send a response. For callback configuration functions it is enabled by default too, but can be disabled by silent_stepper_set_response_expected(). For setter functions it is disabled by default and can be enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

See silent_stepper_set_response_expected() for the list of function ID defines available for this function.

int silent_stepper_set_response_expected(SilentStepper *silent_stepper, uint8_t function_id, bool response_expected)

Changes the response expected flag of the function specified by the function ID parameter. This flag can only be changed for setter (default value: false) and callback configuration functions (default value: true). For getter functions it is always enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

The following function ID defines are available for this function:

  • SILENT_STEPPER_FUNCTION_SET_MAX_VELOCITY = 1
  • SILENT_STEPPER_FUNCTION_SET_SPEED_RAMPING = 4
  • SILENT_STEPPER_FUNCTION_FULL_BRAKE = 6
  • SILENT_STEPPER_FUNCTION_SET_CURRENT_POSITION = 7
  • SILENT_STEPPER_FUNCTION_SET_TARGET_POSITION = 9
  • SILENT_STEPPER_FUNCTION_SET_STEPS = 11
  • SILENT_STEPPER_FUNCTION_SET_STEP_CONFIGURATION = 14
  • SILENT_STEPPER_FUNCTION_DRIVE_FORWARD = 16
  • SILENT_STEPPER_FUNCTION_DRIVE_BACKWARD = 17
  • SILENT_STEPPER_FUNCTION_STOP = 18
  • SILENT_STEPPER_FUNCTION_SET_MOTOR_CURRENT = 22
  • SILENT_STEPPER_FUNCTION_ENABLE = 24
  • SILENT_STEPPER_FUNCTION_DISABLE = 25
  • SILENT_STEPPER_FUNCTION_SET_BASIC_CONFIGURATION = 27
  • SILENT_STEPPER_FUNCTION_SET_SPREADCYCLE_CONFIGURATION = 29
  • SILENT_STEPPER_FUNCTION_SET_STEALTH_CONFIGURATION = 31
  • SILENT_STEPPER_FUNCTION_SET_COOLSTEP_CONFIGURATION = 33
  • SILENT_STEPPER_FUNCTION_SET_MISC_CONFIGURATION = 35
  • SILENT_STEPPER_FUNCTION_SET_MINIMUM_VOLTAGE = 38
  • SILENT_STEPPER_FUNCTION_SET_TIME_BASE = 42
  • SILENT_STEPPER_FUNCTION_SET_ALL_DATA_PERIOD = 45
  • SILENT_STEPPER_FUNCTION_SET_SPITFP_BAUDRATE_CONFIG = 231
  • SILENT_STEPPER_FUNCTION_SET_SPITFP_BAUDRATE = 234
  • SILENT_STEPPER_FUNCTION_ENABLE_STATUS_LED = 238
  • SILENT_STEPPER_FUNCTION_DISABLE_STATUS_LED = 239
  • SILENT_STEPPER_FUNCTION_RESET = 243
int silent_stepper_set_response_expected_all(SilentStepper *silent_stepper, bool response_expected)

Changes the response expected flag for all setter and callback configuration functions of this device at once.

int silent_stepper_set_spitfp_baudrate_config(SilentStepper *silent_stepper, bool enable_dynamic_baudrate, uint32_t minimum_dynamic_baudrate)

The SPITF protocol can be used with a dynamic baudrate. If the dynamic baudrate is enabled, the Brick will try to adapt the baudrate for the communication between Bricks and Bricklets according to the amount of data that is transferred.

The baudrate will be increased exponentially if lots of data is send/received and decreased linearly if little data is send/received.

This lowers the baudrate in applications where little data is transferred (e.g. a weather station) and increases the robustness. If there is lots of data to transfer (e.g. Thermal Imaging Bricklet) it automatically increases the baudrate as needed.

In cases where some data has to transferred as fast as possible every few seconds (e.g. RS485 Bricklet with a high baudrate but small payload) you may want to turn the dynamic baudrate off to get the highest possible performance.

The maximum value of the baudrate can be set per port with the function silent_stepper_set_spitfp_baudrate(). If the dynamic baudrate is disabled, the baudrate as set by silent_stepper_set_spitfp_baudrate() will be used statically.

The minimum dynamic baudrate has a value range of 400000 to 2000000 baud.

By default dynamic baudrate is enabled and the minimum dynamic baudrate is 400000.

New in version 2.0.4 (Firmware).

int silent_stepper_get_spitfp_baudrate_config(SilentStepper *silent_stepper, bool *ret_enable_dynamic_baudrate, uint32_t *ret_minimum_dynamic_baudrate)

Returns the baudrate config, see silent_stepper_set_spitfp_baudrate_config().

New in version 2.0.4 (Firmware).

int silent_stepper_get_send_timeout_count(SilentStepper *silent_stepper, uint8_t communication_method, uint32_t *ret_timeout_count)

Returns the timeout count for the different communication methods.

The methods 0-2 are available for all Bricks, 3-7 only for Master Bricks.

This function is mostly used for debugging during development, in normal operation the counters should nearly always stay at 0.

The following defines are available for this function:

  • SILENT_STEPPER_COMMUNICATION_METHOD_NONE = 0
  • SILENT_STEPPER_COMMUNICATION_METHOD_USB = 1
  • SILENT_STEPPER_COMMUNICATION_METHOD_SPI_STACK = 2
  • SILENT_STEPPER_COMMUNICATION_METHOD_CHIBI = 3
  • SILENT_STEPPER_COMMUNICATION_METHOD_RS485 = 4
  • SILENT_STEPPER_COMMUNICATION_METHOD_WIFI = 5
  • SILENT_STEPPER_COMMUNICATION_METHOD_ETHERNET = 6
  • SILENT_STEPPER_COMMUNICATION_METHOD_WIFI_V2 = 7
int silent_stepper_set_spitfp_baudrate(SilentStepper *silent_stepper, char bricklet_port, uint32_t baudrate)

Sets the baudrate for a specific Bricklet port ('a' - 'd'). The baudrate can be in the range 400000 to 2000000.

If you want to increase the throughput of Bricklets you can increase the baudrate. If you get a high error count because of high interference (see silent_stepper_get_spitfp_error_count()) you can decrease the baudrate.

If the dynamic baudrate feature is enabled, the baudrate set by this function corresponds to the maximum baudrate (see silent_stepper_set_spitfp_baudrate_config()).

Regulatory testing is done with the default baudrate. If CE compatibility or similar is necessary in you applications we recommend to not change the baudrate.

The default baudrate for all ports is 1400000.

int silent_stepper_get_spitfp_baudrate(SilentStepper *silent_stepper, char bricklet_port, uint32_t *ret_baudrate)

Returns the baudrate for a given Bricklet port, see silent_stepper_set_spitfp_baudrate().

int silent_stepper_get_spitfp_error_count(SilentStepper *silent_stepper, char bricklet_port, uint32_t *ret_error_count_ack_checksum, uint32_t *ret_error_count_message_checksum, uint32_t *ret_error_count_frame, uint32_t *ret_error_count_overflow)

Returns the error count for the communication between Brick and Bricklet.

The errors are divided into

  • ACK checksum errors,
  • message checksum errors,
  • framing errors and
  • overflow errors.

The errors counts are for errors that occur on the Brick side. All Bricklets have a similar function that returns the errors on the Bricklet side.

int silent_stepper_enable_status_led(SilentStepper *silent_stepper)

Enables the status LED.

The status LED is the blue LED next to the USB connector. If enabled is is on and it flickers if data is transfered. If disabled it is always off.

The default state is enabled.

int silent_stepper_disable_status_led(SilentStepper *silent_stepper)

Disables the status LED.

The status LED is the blue LED next to the USB connector. If enabled is is on and it flickers if data is transfered. If disabled it is always off.

The default state is enabled.

int silent_stepper_is_status_led_enabled(SilentStepper *silent_stepper, bool *ret_enabled)

Returns true if the status LED is enabled, false otherwise.

int silent_stepper_get_protocol1_bricklet_name(SilentStepper *silent_stepper, char port, uint8_t *ret_protocol_version, uint8_t ret_firmware_version[3], char ret_name[40])

Returns the firmware and protocol version and the name of the Bricklet for a given port.

This functions sole purpose is to allow automatic flashing of v1.x.y Bricklet plugins.

int silent_stepper_get_chip_temperature(SilentStepper *silent_stepper, int16_t *ret_temperature)

Returns the temperature in °C/10 as measured inside the microcontroller. The value returned is not the ambient temperature!

The temperature is only proportional to the real temperature and it has an accuracy of +-15%. Practically it is only useful as an indicator for temperature changes.

int silent_stepper_reset(SilentStepper *silent_stepper)

Calling this function will reset the Brick. Calling this function on a Brick inside of a stack will reset the whole stack.

After a reset you have to create new device objects, calling functions on the existing ones will result in undefined behavior!

int silent_stepper_get_identity(SilentStepper *silent_stepper, char ret_uid[8], char ret_connected_uid[8], char *ret_position, uint8_t ret_hardware_version[3], uint8_t ret_firmware_version[3], uint16_t *ret_device_identifier)

Returns the UID, the UID where the Brick is connected to, the position, the hardware and firmware version as well as the device identifier.

The position can be '0'-'8' (stack position).

The device identifier numbers can be found here. There is also a constant for the device identifier of this Brick.

Callback Configuration Functions

void silent_stepper_register_callback(SilentStepper *silent_stepper, int16_t callback_id, void *function, void *user_data)

Registers the given function with the given callback_id. The user_data will be passed as the last parameter to the function.

The available callback IDs with corresponding function signatures are listed below.

int silent_stepper_set_minimum_voltage(SilentStepper *silent_stepper, uint16_t voltage)

Sets the minimum voltage in mV, below which the SILENT_STEPPER_CALLBACK_UNDER_VOLTAGE callback is triggered. The minimum possible value that works with the Slient Stepper Brick is 8V. You can use this function to detect the discharge of a battery that is used to drive the stepper motor. If you have a fixed power supply, you likely do not need this functionality.

The default value is 8V.

int silent_stepper_get_minimum_voltage(SilentStepper *silent_stepper, uint16_t *ret_voltage)

Returns the minimum voltage as set by silent_stepper_set_minimum_voltage().

int silent_stepper_set_all_data_period(SilentStepper *silent_stepper, uint32_t period)

Sets the period in ms with which the SILENT_STEPPER_CALLBACK_ALL_DATA callback is triggered periodically. A value of 0 turns the callback off.

int silent_stepper_get_all_data_period(SilentStepper *silent_stepper, uint32_t *ret_period)

Returns the period as set by silent_stepper_set_all_data_period().

Callbacks

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the silent_stepper_register_callback() function. The parameters consist of the device object, the callback ID, the callback function and optional user data:

void my_callback(int p, void *user_data) {
    printf("parameter: %d\n", p);
}

silent_stepper_register_callback(&silent_stepper, SILENT_STEPPER_CALLBACK_EXAMPLE, (void *)my_callback, NULL);

The available constants with corresponding callback function signatures are described below.

Note

Using callbacks for recurring events is always preferred compared to using getters. It will use less USB bandwidth and the latency will be a lot better, since there is no round trip time.

SILENT_STEPPER_CALLBACK_UNDER_VOLTAGE
void callback(uint16_t voltage, void *user_data)

This callback is triggered when the input voltage drops below the value set by silent_stepper_set_minimum_voltage(). The parameter is the current voltage given in mV.

SILENT_STEPPER_CALLBACK_POSITION_REACHED
void callback(int32_t position, void *user_data)

This callback is triggered when a position set by silent_stepper_set_steps() or silent_stepper_set_target_position() is reached.

Note

Since we can't get any feedback from the stepper motor, this only works if the acceleration (see silent_stepper_set_speed_ramping()) is set smaller or equal to the maximum acceleration of the motor. Otherwise the motor will lag behind the control value and the callback will be triggered too early.

SILENT_STEPPER_CALLBACK_ALL_DATA
void callback(uint16_t current_velocity, int32_t current_position, int32_t remaining_steps, uint16_t stack_voltage, uint16_t external_voltage, uint16_t current_consumption, void *user_data)

This callback is triggered periodically with the period that is set by silent_stepper_set_all_data_period(). The parameters are: the current velocity, the current position, the remaining steps, the stack voltage, the external voltage and the current consumption of the stepper motor.

SILENT_STEPPER_CALLBACK_NEW_STATE
void callback(uint8_t state_new, uint8_t state_previous, void *user_data)

This callback is triggered whenever the Slient Stepper Brick enters a new state. It returns the new state as well as the previous state.

The following defines are available for this function:

  • SILENT_STEPPER_STATE_STOP = 1
  • SILENT_STEPPER_STATE_ACCELERATION = 2
  • SILENT_STEPPER_STATE_RUN = 3
  • SILENT_STEPPER_STATE_DEACCELERATION = 4
  • SILENT_STEPPER_STATE_DIRECTION_CHANGE_TO_FORWARD = 5
  • SILENT_STEPPER_STATE_DIRECTION_CHANGE_TO_BACKWARD = 6

Constants

SILENT_STEPPER_DEVICE_IDENTIFIER

This constant is used to identify a Silent Stepper Brick.

The silent_stepper_get_identity() function and the IPCON_CALLBACK_ENUMERATE callback of the IP Connection have a device_identifier parameter to specify the Brick's or Bricklet's type.

SILENT_STEPPER_DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Silent Stepper Brick.