C/C++ - Outdoor Weather Bricklet

This is the description of the C/C++ API bindings for the Outdoor Weather Bricklet. General information and technical specifications for the Outdoor Weather Bricklet 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).

Callback

Download (example_callback.c)

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#include <stdio.h>

#include "ip_connection.h"
#include "bricklet_outdoor_weather.h"

#define HOST "localhost"
#define PORT 4223
#define UID "XYZ" // Change XYZ to the UID of your Outdoor Weather Bricklet

// Callback function for station data callback
void cb_station_data(uint8_t identifier, int16_t temperature, uint8_t humidity,
                     uint32_t wind_speed, uint32_t gust_speed, uint32_t rain,
                     uint8_t wind_direction, bool battery_low, void *user_data) {
    (void)user_data; // avoid unused parameter warning

    printf("Identifier (Station): %u\n", identifier);
    printf("Temperature (Station): %f °C\n", temperature/10.0);
    printf("Humidity (Station): %u %%RH\n", humidity);
    printf("Wind Speed (Station): %f m/s\n", wind_speed/10.0);
    printf("Gust Speed (Station): %f m/s\n", gust_speed/10.0);
    printf("Rain (Station): %f mm\n", rain/10.0);
    printf("Wind Direction (Station): %u\n", wind_direction);
    printf("Battery Low (Station): %s\n", battery_low ? "true" : "false");
    printf("\n");
}

// Callback function for sensor data callback
void cb_sensor_data(uint8_t identifier, int16_t temperature, uint8_t humidity,
                    void *user_data) {
    (void)user_data; // avoid unused parameter warning

    printf("Identifier (Sensor): %u\n", identifier);
    printf("Temperature (Sensor): %f °C\n", temperature/10.0);
    printf("Humidity (Sensor): %u %%RH\n", humidity);
    printf("\n");
}

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

    // Create device object
    OutdoorWeather ow;
    outdoor_weather_create(&ow, 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

    // Enable station data callbacks
    outdoor_weather_set_station_callback_configuration(&ow, true);

    // Enable sensor data callbacks
    outdoor_weather_set_sensor_callback_configuration(&ow, true);

    // Register station data callback to function cb_station_data
    outdoor_weather_register_callback(&ow,
                                      OUTDOOR_WEATHER_CALLBACK_STATION_DATA,
                                      (void *)cb_station_data,
                                      NULL);

    // Register sensor data callback to function cb_sensor_data
    outdoor_weather_register_callback(&ow,
                                      OUTDOOR_WEATHER_CALLBACK_SENSOR_DATA,
                                      (void *)cb_sensor_data,
                                      NULL);

    printf("Press key to exit\n");
    getchar();
    outdoor_weather_destroy(&ow);
    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 outdoor_weather_create(OutdoorWeather *outdoor_weather, const char *uid, IPConnection *ipcon)

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

OutdoorWeather outdoor_weather;
outdoor_weather_create(&outdoor_weather, "YOUR_DEVICE_UID", &ipcon);

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

void outdoor_weather_destroy(OutdoorWeather *outdoor_weather)

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

int outdoor_weather_get_station_identifiers(OutdoorWeather *outdoor_weather, uint8_t *ret_identifiers, uint16_t *ret_identifiers_length)

Returns the identifiers (number between 0 and 255) of all stations that have been seen since the startup of the Bricklet.

Each station gives itself a random identifier on first startup.

int outdoor_weather_get_sensor_identifiers(OutdoorWeather *outdoor_weather, uint8_t *ret_identifiers, uint16_t *ret_identifiers_length)

Returns the identifiers (number between 0 and 255) of all sensors that have been seen since the startup of the Bricklet.

Each sensor gives itself a random identifier on first startup.

int outdoor_weather_get_station_data(OutdoorWeather *outdoor_weather, uint8_t identifier, int16_t *ret_temperature, uint8_t *ret_humidity, uint32_t *ret_wind_speed, uint32_t *ret_gust_speed, uint32_t *ret_rain, uint8_t *ret_wind_direction, bool *ret_battery_low, uint16_t *ret_last_change)

Returns the last received data for a station with the given identifier. Call outdoor_weather_get_station_identifiers() for a list of all available identifiers.

The return values are:

  • Temperature in °C/10,
  • Humidity in %RH,
  • Wind Speed in m/10s,
  • Gust Speed in m/10s,
  • Rain Fall in mm/10,
  • Wind Direction (N, NNE, NE, ENE, E, ESE, SE, SSE, S, SSW, SW, WSW, W, WNW, NW, NNW),
  • Battery Low (true or false) and
  • Last Change (time in seconds since the reception of this data).

The following defines are available for this function:

  • OUTDOOR_WEATHER_WIND_DIRECTION_N = 0
  • OUTDOOR_WEATHER_WIND_DIRECTION_NNE = 1
  • OUTDOOR_WEATHER_WIND_DIRECTION_NE = 2
  • OUTDOOR_WEATHER_WIND_DIRECTION_ENE = 3
  • OUTDOOR_WEATHER_WIND_DIRECTION_E = 4
  • OUTDOOR_WEATHER_WIND_DIRECTION_ESE = 5
  • OUTDOOR_WEATHER_WIND_DIRECTION_SE = 6
  • OUTDOOR_WEATHER_WIND_DIRECTION_SSE = 7
  • OUTDOOR_WEATHER_WIND_DIRECTION_S = 8
  • OUTDOOR_WEATHER_WIND_DIRECTION_SSW = 9
  • OUTDOOR_WEATHER_WIND_DIRECTION_SW = 10
  • OUTDOOR_WEATHER_WIND_DIRECTION_WSW = 11
  • OUTDOOR_WEATHER_WIND_DIRECTION_W = 12
  • OUTDOOR_WEATHER_WIND_DIRECTION_WNW = 13
  • OUTDOOR_WEATHER_WIND_DIRECTION_NW = 14
  • OUTDOOR_WEATHER_WIND_DIRECTION_NNW = 15
  • OUTDOOR_WEATHER_WIND_DIRECTION_ERROR = 255
int outdoor_weather_get_sensor_data(OutdoorWeather *outdoor_weather, uint8_t identifier, int16_t *ret_temperature, uint8_t *ret_humidity, uint16_t *ret_last_change)

Returns the last measured data for a sensor with the given identifier. Call outdoor_weather_get_sensor_identifiers() for a list of all available identifiers.

The return values are:

  • Temperature in °C/10,
  • Humidity in %RH and
  • Last Change (time in seconds since the last reception of data).

Advanced Functions

int outdoor_weather_get_api_version(OutdoorWeather *outdoor_weather, 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 outdoor_weather_get_response_expected(OutdoorWeather *outdoor_weather, 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 outdoor_weather_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 outdoor_weather_set_response_expected() for the list of function ID defines available for this function.

int outdoor_weather_set_response_expected(OutdoorWeather *outdoor_weather, 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:

  • OUTDOOR_WEATHER_FUNCTION_SET_STATION_CALLBACK_CONFIGURATION = 5
  • OUTDOOR_WEATHER_FUNCTION_SET_SENSOR_CALLBACK_CONFIGURATION = 7
  • OUTDOOR_WEATHER_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • OUTDOOR_WEATHER_FUNCTION_SET_STATUS_LED_CONFIG = 239
  • OUTDOOR_WEATHER_FUNCTION_RESET = 243
  • OUTDOOR_WEATHER_FUNCTION_WRITE_UID = 248
int outdoor_weather_set_response_expected_all(OutdoorWeather *outdoor_weather, bool response_expected)

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

int outdoor_weather_get_spitfp_error_count(OutdoorWeather *outdoor_weather, 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 Bricklet side. All Bricks have a similar function that returns the errors on the Brick side.

int outdoor_weather_set_bootloader_mode(OutdoorWeather *outdoor_weather, uint8_t mode, uint8_t *ret_status)

Sets the bootloader mode and returns the status after the requested mode change was instigated.

You can change from bootloader mode to firmware mode and vice versa. A change from bootloader mode to firmware mode will only take place if the entry function, device identifier and CRC are present and correct.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

The following defines are available for this function:

  • OUTDOOR_WEATHER_BOOTLOADER_MODE_BOOTLOADER = 0
  • OUTDOOR_WEATHER_BOOTLOADER_MODE_FIRMWARE = 1
  • OUTDOOR_WEATHER_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • OUTDOOR_WEATHER_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • OUTDOOR_WEATHER_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
  • OUTDOOR_WEATHER_BOOTLOADER_STATUS_OK = 0
  • OUTDOOR_WEATHER_BOOTLOADER_STATUS_INVALID_MODE = 1
  • OUTDOOR_WEATHER_BOOTLOADER_STATUS_NO_CHANGE = 2
  • OUTDOOR_WEATHER_BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
  • OUTDOOR_WEATHER_BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
  • OUTDOOR_WEATHER_BOOTLOADER_STATUS_CRC_MISMATCH = 5
int outdoor_weather_get_bootloader_mode(OutdoorWeather *outdoor_weather, uint8_t *ret_mode)

Returns the current bootloader mode, see outdoor_weather_set_bootloader_mode().

The following defines are available for this function:

  • OUTDOOR_WEATHER_BOOTLOADER_MODE_BOOTLOADER = 0
  • OUTDOOR_WEATHER_BOOTLOADER_MODE_FIRMWARE = 1
  • OUTDOOR_WEATHER_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • OUTDOOR_WEATHER_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • OUTDOOR_WEATHER_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
int outdoor_weather_set_write_firmware_pointer(OutdoorWeather *outdoor_weather, uint32_t pointer)

Sets the firmware pointer for outdoor_weather_write_firmware(). The pointer has to be increased by chunks of size 64. The data is written to flash every 4 chunks (which equals to one page of size 256).

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

int outdoor_weather_write_firmware(OutdoorWeather *outdoor_weather, uint8_t data[64], uint8_t *ret_status)

Writes 64 Bytes of firmware at the position as written by outdoor_weather_set_write_firmware_pointer() before. The firmware is written to flash every 4 chunks.

You can only write firmware in bootloader mode.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

int outdoor_weather_set_status_led_config(OutdoorWeather *outdoor_weather, uint8_t config)

Sets the status LED configuration. By default the LED shows communication traffic between Brick and Bricklet, it flickers once for every 10 received data packets.

You can also turn the LED permanently on/off or show a heartbeat.

If the Bricklet is in bootloader mode, the LED is will show heartbeat by default.

The following defines are available for this function:

  • OUTDOOR_WEATHER_STATUS_LED_CONFIG_OFF = 0
  • OUTDOOR_WEATHER_STATUS_LED_CONFIG_ON = 1
  • OUTDOOR_WEATHER_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • OUTDOOR_WEATHER_STATUS_LED_CONFIG_SHOW_STATUS = 3
int outdoor_weather_get_status_led_config(OutdoorWeather *outdoor_weather, uint8_t *ret_config)

Returns the configuration as set by outdoor_weather_set_status_led_config()

The following defines are available for this function:

  • OUTDOOR_WEATHER_STATUS_LED_CONFIG_OFF = 0
  • OUTDOOR_WEATHER_STATUS_LED_CONFIG_ON = 1
  • OUTDOOR_WEATHER_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • OUTDOOR_WEATHER_STATUS_LED_CONFIG_SHOW_STATUS = 3
int outdoor_weather_get_chip_temperature(OutdoorWeather *outdoor_weather, int16_t *ret_temperature)

Returns the temperature in °C 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 bad accuracy. Practically it is only useful as an indicator for temperature changes.

int outdoor_weather_reset(OutdoorWeather *outdoor_weather)

Calling this function will reset the Bricklet. All configurations will be lost.

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

int outdoor_weather_write_uid(OutdoorWeather *outdoor_weather, uint32_t uid)

Writes a new UID into flash. If you want to set a new UID you have to decode the Base58 encoded UID string into an integer first.

We recommend that you use Brick Viewer to change the UID.

int outdoor_weather_read_uid(OutdoorWeather *outdoor_weather, uint32_t *ret_uid)

Returns the current UID as an integer. Encode as Base58 to get the usual string version.

int outdoor_weather_get_identity(OutdoorWeather *outdoor_weather, 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 Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.

The position can be 'a', 'b', 'c' or 'd'.

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

Callback Configuration Functions

void outdoor_weather_register_callback(OutdoorWeather *outdoor_weather, 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 outdoor_weather_set_station_callback_configuration(OutdoorWeather *outdoor_weather, bool enable_callback)

Turns callback for station data on or off. Default is off.

int outdoor_weather_get_station_callback_configuration(OutdoorWeather *outdoor_weather, bool *ret_enable_callback)

Returns the configuration as set by outdoor_weather_set_station_callback_configuration().

int outdoor_weather_set_sensor_callback_configuration(OutdoorWeather *outdoor_weather, bool enable_callback)

Turns callback for sensor data on or off. Default is off.

int outdoor_weather_get_sensor_callback_configuration(OutdoorWeather *outdoor_weather, bool *ret_enable_callback)

Returns the configuration as set by outdoor_weather_set_sensor_callback_configuration().

Callbacks

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the outdoor_weather_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);
}

outdoor_weather_register_callback(&outdoor_weather, OUTDOOR_WEATHER_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.

OUTDOOR_WEATHER_CALLBACK_STATION_DATA
void callback(uint8_t identifier, int16_t temperature, uint8_t humidity, uint32_t wind_speed, uint32_t gust_speed, uint32_t rain, uint8_t wind_direction, bool battery_low, void *user_data)

Reports the station data every time a new data packet is received. See outdoor_weather_get_station_data() for information about the data.

For each station the callback will be triggered about every 45 seconds.

Turn the callback on/off with outdoor_weather_set_station_callback_configuration() (by default it is turned off).

The following defines are available for this function:

  • OUTDOOR_WEATHER_WIND_DIRECTION_N = 0
  • OUTDOOR_WEATHER_WIND_DIRECTION_NNE = 1
  • OUTDOOR_WEATHER_WIND_DIRECTION_NE = 2
  • OUTDOOR_WEATHER_WIND_DIRECTION_ENE = 3
  • OUTDOOR_WEATHER_WIND_DIRECTION_E = 4
  • OUTDOOR_WEATHER_WIND_DIRECTION_ESE = 5
  • OUTDOOR_WEATHER_WIND_DIRECTION_SE = 6
  • OUTDOOR_WEATHER_WIND_DIRECTION_SSE = 7
  • OUTDOOR_WEATHER_WIND_DIRECTION_S = 8
  • OUTDOOR_WEATHER_WIND_DIRECTION_SSW = 9
  • OUTDOOR_WEATHER_WIND_DIRECTION_SW = 10
  • OUTDOOR_WEATHER_WIND_DIRECTION_WSW = 11
  • OUTDOOR_WEATHER_WIND_DIRECTION_W = 12
  • OUTDOOR_WEATHER_WIND_DIRECTION_WNW = 13
  • OUTDOOR_WEATHER_WIND_DIRECTION_NW = 14
  • OUTDOOR_WEATHER_WIND_DIRECTION_NNW = 15
  • OUTDOOR_WEATHER_WIND_DIRECTION_ERROR = 255
OUTDOOR_WEATHER_CALLBACK_SENSOR_DATA
void callback(uint8_t identifier, int16_t temperature, uint8_t humidity, void *user_data)

Reports the sensor data every time a new data packet is received. See outdoor_weather_get_sensor_data() for information about the data.

For each station the callback will be called about every 45 seconds.

Turn the callback on/off with outdoor_weather_set_sensor_callback_configuration() (by default it is turned off).

Constants

OUTDOOR_WEATHER_DEVICE_IDENTIFIER

This constant is used to identify a Outdoor Weather Bricklet.

The outdoor_weather_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.

OUTDOOR_WEATHER_DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Outdoor Weather Bricklet.