Delphi/Lazarus - Energy Monitor Bricklet

This is the description of the Delphi/Lazarus API bindings for the Energy Monitor Bricklet. General information and technical specifications for the Energy Monitor Bricklet are summarized in its hardware description.

An installation guide for the Delphi/Lazarus API bindings is part of their general description.

Examples

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

Simple

Download (ExampleSimple.pas)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
program ExampleSimple;

{$ifdef MSWINDOWS}{$apptype CONSOLE}{$endif}
{$ifdef FPC}{$mode OBJFPC}{$H+}{$endif}

uses
  SysUtils, IPConnection, BrickletEnergyMonitor;

type
  TExample = class
  private
    ipcon: TIPConnection;
    em: TBrickletEnergyMonitor;
  public
    procedure Execute;
  end;

const
  HOST = 'localhost';
  PORT = 4223;
  UID = 'XYZ'; { Change XYZ to the UID of your Energy Monitor Bricklet }

var
  e: TExample;

procedure TExample.Execute;
var voltage, current, energy, realPower, apparentPower, reactivePower: longint;
    powerFactor, frequency: word;
begin
  { Create IP connection }
  ipcon := TIPConnection.Create;

  { Create device object }
  em := TBrickletEnergyMonitor.Create(UID, ipcon);

  { Connect to brickd }
  ipcon.Connect(HOST, PORT);
  { Don't use device before ipcon is connected }

  { Get current Energy Data }
  em.GetEnergyData(voltage, current, energy, realPower, apparentPower, reactivePower,
                   powerFactor, frequency);

  WriteLn(Format('Voltage: %f V', [voltage/100.0]));
  WriteLn(Format('Current: %f A', [current/100.0]));
  WriteLn(Format('Energy: %f Wh', [energy/100.0]));
  WriteLn(Format('Real Power: %f h', [realPower/100.0]));
  WriteLn(Format('Apparent Power: %f VA', [apparentPower/100.0]));
  WriteLn(Format('Reactive Power: %f VAR', [reactivePower/100.0]));
  WriteLn(Format('Power Factor: %f', [powerFactor/1000.0]));
  WriteLn(Format('Frequency: %f Hz', [frequency/100.0]));

  WriteLn('Press key to exit');
  ReadLn;
  ipcon.Destroy; { Calls ipcon.Disconnect internally }
end;

begin
  e := TExample.Create;
  e.Execute;
  e.Destroy;
end.

Callback

Download (ExampleCallback.pas)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
program ExampleCallback;

{$ifdef MSWINDOWS}{$apptype CONSOLE}{$endif}
{$ifdef FPC}{$mode OBJFPC}{$H+}{$endif}

uses
  SysUtils, IPConnection, BrickletEnergyMonitor;

type
  TExample = class
  private
    ipcon: TIPConnection;
    em: TBrickletEnergyMonitor;
  public
    procedure EnergyDataCB(sender: TBrickletEnergyMonitor; const voltage: longint;
                           const current: longint; const energy: longint;
                           const realPower: longint; const apparentPower: longint;
                           const reactivePower: longint; const powerFactor: word;
                           const frequency: word);
    procedure Execute;
  end;

const
  HOST = 'localhost';
  PORT = 4223;
  UID = 'XYZ'; { Change XYZ to the UID of your Energy Monitor Bricklet }

var
  e: TExample;

{ Callback procedure for Energy Data callback }
procedure TExample.EnergyDataCB(sender: TBrickletEnergyMonitor; const voltage: longint;
                                const current: longint; const energy: longint;
                                const realPower: longint; const apparentPower: longint;
                                const reactivePower: longint; const powerFactor: word;
                                const frequency: word);
begin
  WriteLn(Format('Voltage: %f V', [voltage/100.0]));
  WriteLn(Format('Current: %f A', [current/100.0]));
  WriteLn(Format('Energy: %f Wh', [energy/100.0]));
  WriteLn(Format('Real Power: %f h', [realPower/100.0]));
  WriteLn(Format('Apparent Power: %f VA', [apparentPower/100.0]));
  WriteLn(Format('Reactive Power: %f VAR', [reactivePower/100.0]));
  WriteLn(Format('Power Factor: %f', [powerFactor/1000.0]));
  WriteLn(Format('Frequency: %f Hz', [frequency/100.0]));
  WriteLn('');
end;

procedure TExample.Execute;
begin
  { Create IP connection }
  ipcon := TIPConnection.Create;

  { Create device object }
  em := TBrickletEnergyMonitor.Create(UID, ipcon);

  { Connect to brickd }
  ipcon.Connect(HOST, PORT);
  { Don't use device before ipcon is connected }

  { Register Energy Data callback to procedure EnergyDataCB }
  em.OnEnergyData := {$ifdef FPC}@{$endif}EnergyDataCB;

  { Set period for Energy Data callback to 1s (1000ms) }
  em.SetEnergyDataCallbackConfiguration(1000, false);

  WriteLn('Press key to exit');
  ReadLn;
  ipcon.Destroy; { Calls ipcon.Disconnect internally }
end;

begin
  e := TExample.Create;
  e.Execute;
  e.Destroy;
end.

API

Since Delphi does not support multiple return values directly, we use the out keyword to return multiple values from a function.

All functions and procedures listed below are thread-safe.

Basic Functions

constructor TBrickletEnergyMonitor.Create(const uid: string; ipcon: TIPConnection)

Creates an object with the unique device ID uid:

energyMonitor := TBrickletEnergyMonitor.Create('YOUR_DEVICE_UID', ipcon);

This object can then be used after the IP Connection is connected (see examples above).

procedure TBrickletEnergyMonitor.GetEnergyData(out voltage: longint; out current: longint; out energy: longint; out realPower: longint; out apparentPower: longint; out reactivePower: longint; out powerFactor: word; out frequency: word)

Returns all of the measurements that are done by the Energy Monitor Bricklet.

  • Voltage (V): Voltage RMS with a resolution of 10mV (example: 230.05V = 23005)
  • Current (A): Current RMS with a resolution of 10mA (example: 1.42A = 142)
  • Energy (Wh): Energy (integrated over time) with a resolution of 10mWh (example: 1.1kWh = 110000)
  • Real Power (W): Real Power with a resolution of 10mW (example: 1234.56W = 123456)
  • Apparent Power (VA): Apparent Power with a resolution of 10mVA (example: 1234.56VA = 123456)
  • Reactive Power (VAR): Reactive Power with a resolution of 10mVAR (example: 1234.56VAR = 123456)
  • Power Factor: Power Factor with a resolution of 1/1000 (example: PF 0.995 = 995)
  • Frequency (Hz): AC Frequency of the mains voltage with a resolution of 1/100 Hz (example: 50Hz = 5000)

The frequency is recalculated every 6 seconds.

All other values are integrated over 10 zero-crossings of the voltage sine wave. With a standard AC mains voltage frequency of 50Hz this results in a 5 measurements per second (or an integration time of 200ms per measurement).

If no voltage transformer is connected, the Bricklet will use the current waveform to calculate the frequency and it will use an integration time of 10 zero-crossings of the current waveform.

procedure TBrickletEnergyMonitor.ResetEnergy

Sets the energy value (see GetEnergyData) back to 0Wh.

function TBrickletEnergyMonitor.GetWaveform: array [0..1535] of smallint

Returns a snapshot of the voltage and current waveform. The values in the returned array alternate between voltage and current. The data from one getter call contains 768 data points for voltage and current, which correspond to about 3 full sine waves.

The voltage is given with a resolution of 100mV and the current is given with a resolution of 10mA.

This data is meant to be used for a non-realtime graphical representation of the voltage and current waveforms.

procedure TBrickletEnergyMonitor.GetTransformerStatus(out voltageTransformerConnected: boolean; out currentTransformerConnected: boolean)

Returns true if a voltage/current transformer is connected to the Bricklet.

procedure TBrickletEnergyMonitor.SetTransformerCalibration(const voltageRatio: word; const currentRatio: word; const phaseShift: smallint)

Sets the transformer ratio for the voltage and current transformer in 1/100 form.

Example: If your mains voltage is 230V, you use 9V voltage transformer and a 1V:30A current clamp your voltage ratio is 230/9 = 25.56 and your current ratio is 30/1 = 30.

In this case you have to set the values 2556 and 3000 for voltage ratio and current ratio.

The calibration is saved in non-volatile memory, you only have to set it once.

By default the voltage ratio is set to 1923 and the current ratio is set to 3000.

Set the phase shift to 0. It is for future use and currently not supported by the Bricklet.

procedure TBrickletEnergyMonitor.GetTransformerCalibration(out voltageRatio: word; out currentRatio: word; out phaseShift: smallint)

Returns the transformer calibration as set by SetTransformerCalibration.

procedure TBrickletEnergyMonitor.CalibrateOffset

Calling this function will start an offset calibration. The offset calibration will integrate the voltage and current waveform over a longer time period to find the 0 transition point in the sine wave.

The Bricklet comes with a factory-calibrated offset value, you should not have to call this function.

If you want to re-calibrate the offset we recommend that you connect a load that has a smooth sinusoidal voltage and current waveform. Alternatively you can also short both inputs.

The calibration is saved in non-volatile memory, you only have to set it once.

Advanced Functions

function TBrickletEnergyMonitor.GetAPIVersion: array [0..2] of byte

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.

function TBrickletEnergyMonitor.GetResponseExpected(const functionId: byte): boolean

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 SetResponseExpected. 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.

The following constants are available for this function:

  • BRICKLET_ENERGY_MONITOR_FUNCTION_RESET_ENERGY = 2
  • BRICKLET_ENERGY_MONITOR_FUNCTION_SET_TRANSFORMER_CALIBRATION = 5
  • BRICKLET_ENERGY_MONITOR_FUNCTION_CALIBRATE_OFFSET = 7
  • BRICKLET_ENERGY_MONITOR_FUNCTION_SET_ENERGY_DATA_CALLBACK_CONFIGURATION = 8
  • BRICKLET_ENERGY_MONITOR_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BRICKLET_ENERGY_MONITOR_FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BRICKLET_ENERGY_MONITOR_FUNCTION_RESET = 243
  • BRICKLET_ENERGY_MONITOR_FUNCTION_WRITE_UID = 248
procedure TBrickletEnergyMonitor.SetResponseExpected(const functionId: byte; const responseExpected: boolean)

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 constants are available for this function:

  • BRICKLET_ENERGY_MONITOR_FUNCTION_RESET_ENERGY = 2
  • BRICKLET_ENERGY_MONITOR_FUNCTION_SET_TRANSFORMER_CALIBRATION = 5
  • BRICKLET_ENERGY_MONITOR_FUNCTION_CALIBRATE_OFFSET = 7
  • BRICKLET_ENERGY_MONITOR_FUNCTION_SET_ENERGY_DATA_CALLBACK_CONFIGURATION = 8
  • BRICKLET_ENERGY_MONITOR_FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BRICKLET_ENERGY_MONITOR_FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BRICKLET_ENERGY_MONITOR_FUNCTION_RESET = 243
  • BRICKLET_ENERGY_MONITOR_FUNCTION_WRITE_UID = 248
procedure TBrickletEnergyMonitor.SetResponseExpectedAll(const responseExpected: boolean)

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

procedure TBrickletEnergyMonitor.GetSPITFPErrorCount(out errorCountAckChecksum: longword; out errorCountMessageChecksum: longword; out errorCountFrame: longword; out errorCountOverflow: longword)

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.

function TBrickletEnergyMonitor.SetBootloaderMode(const mode: byte): byte

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 constants are available for this function:

  • BRICKLET_ENERGY_MONITOR_BOOTLOADER_MODE_BOOTLOADER = 0
  • BRICKLET_ENERGY_MONITOR_BOOTLOADER_MODE_FIRMWARE = 1
  • BRICKLET_ENERGY_MONITOR_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BRICKLET_ENERGY_MONITOR_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BRICKLET_ENERGY_MONITOR_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
  • BRICKLET_ENERGY_MONITOR_BOOTLOADER_STATUS_OK = 0
  • BRICKLET_ENERGY_MONITOR_BOOTLOADER_STATUS_INVALID_MODE = 1
  • BRICKLET_ENERGY_MONITOR_BOOTLOADER_STATUS_NO_CHANGE = 2
  • BRICKLET_ENERGY_MONITOR_BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
  • BRICKLET_ENERGY_MONITOR_BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
  • BRICKLET_ENERGY_MONITOR_BOOTLOADER_STATUS_CRC_MISMATCH = 5
function TBrickletEnergyMonitor.GetBootloaderMode: byte

Returns the current bootloader mode, see SetBootloaderMode.

The following constants are available for this function:

  • BRICKLET_ENERGY_MONITOR_BOOTLOADER_MODE_BOOTLOADER = 0
  • BRICKLET_ENERGY_MONITOR_BOOTLOADER_MODE_FIRMWARE = 1
  • BRICKLET_ENERGY_MONITOR_BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BRICKLET_ENERGY_MONITOR_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BRICKLET_ENERGY_MONITOR_BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
procedure TBrickletEnergyMonitor.SetWriteFirmwarePointer(const pointer: longword)

Sets the firmware pointer for WriteFirmware. 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.

function TBrickletEnergyMonitor.WriteFirmware(const data: array [0..63] of byte): byte

Writes 64 Bytes of firmware at the position as written by SetWriteFirmwarePointer 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.

procedure TBrickletEnergyMonitor.SetStatusLEDConfig(const config: byte)

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 constants are available for this function:

  • BRICKLET_ENERGY_MONITOR_STATUS_LED_CONFIG_OFF = 0
  • BRICKLET_ENERGY_MONITOR_STATUS_LED_CONFIG_ON = 1
  • BRICKLET_ENERGY_MONITOR_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BRICKLET_ENERGY_MONITOR_STATUS_LED_CONFIG_SHOW_STATUS = 3
function TBrickletEnergyMonitor.GetStatusLEDConfig: byte

Returns the configuration as set by SetStatusLEDConfig

The following constants are available for this function:

  • BRICKLET_ENERGY_MONITOR_STATUS_LED_CONFIG_OFF = 0
  • BRICKLET_ENERGY_MONITOR_STATUS_LED_CONFIG_ON = 1
  • BRICKLET_ENERGY_MONITOR_STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BRICKLET_ENERGY_MONITOR_STATUS_LED_CONFIG_SHOW_STATUS = 3
function TBrickletEnergyMonitor.GetChipTemperature: smallint

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.

procedure TBrickletEnergyMonitor.Reset

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!

procedure TBrickletEnergyMonitor.WriteUID(const uid: longword)

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.

function TBrickletEnergyMonitor.ReadUID: longword

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

procedure TBrickletEnergyMonitor.GetIdentity(out uid: string; out connectedUid: string; out position: char; out hardwareVersion: array [0..2] of byte; out firmwareVersion: array [0..2] of byte; out deviceIdentifier: word)

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

procedure TBrickletEnergyMonitor.SetEnergyDataCallbackConfiguration(const period: longword; const valueHasToChange: boolean)

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

If the value has to change-parameter is set to true, the callback is only triggered after the value has changed. If the value didn't change within the period, the callback is triggered immediately on change.

If it is set to false, the callback is continuously triggered with the period, independent of the value.

The default value is (0, false).

procedure TBrickletEnergyMonitor.GetEnergyDataCallbackConfiguration(out period: longword; out valueHasToChange: boolean)

Returns the callback configuration as set by SetEnergyDataCallbackConfiguration.

Callbacks

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done by assigning a procedure to an callback property of the device object:

procedure TExample.MyCallback(sender: TBrickletEnergyMonitor; const param: word);
begin
  WriteLn(param);
end;

energyMonitor.OnExample := {$ifdef FPC}@{$endif}example.MyCallback;

The available callback property and their type of parameters 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.

property TBrickletEnergyMonitor.OnEnergyData
procedure(sender: TBrickletEnergyMonitor; const voltage: longint; const current: longint; const energy: longint; const realPower: longint; const apparentPower: longint; const reactivePower: longint; const powerFactor: word; const frequency: word) of object;

This callback is triggered periodically according to the configuration set by SetEnergyDataCallbackConfiguration.

The parameters are the same as GetEnergyData.

Constants

const BRICKLET_ENERGY_MONITOR_DEVICE_IDENTIFIER

This constant is used to identify a Energy Monitor Bricklet.

The GetIdentity function and the TIPConnection.OnEnumerate callback of the IP Connection have a deviceIdentifier parameter to specify the Brick's or Bricklet's type.

const BRICKLET_ENERGY_MONITOR_DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Energy Monitor Bricklet.