PAC1944 Click

PAC1944 Click is a compact add-on board that contains an energy monitoring solution. This board features the PAC1944, a multi-channel DC power/energy monitor from Microchip Technology. It uses real-time calibration to minimize offset and gain errors with no input filters required for this device.

Click Product page

Click library

• Author : Stefan Nikolic
• Date : dec 2020.
• Type : I2C type

Software Support

We provide a library for the PAC1944 Click as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

Package can be downloaded/installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on mikroE github account.

Library Description

This library contains API for PAC1944 Click driver.

Standard key functions :

• pac1944_cfg_setup Config Object Initialization function.

  void pac1944_cfg_setup ( pac1944_cfg_t *cfg );

• pac1944_init Initialization function.

  PAC1944_RETVAL pac1944_init ( pac1944_t *ctx, pac1944_cfg_t *cfg );

• pac1944_default_cfg Click Default Configuration function.

  void pac1944_default_cfg ( pac1944_t *ctx );

Example key functions :

• pac1944_setup_config PAC1944 setup config function.

  void pac1944_setup_config ( pac1944_t *ctx, pac1944_setup_t cfg_data );

• pac1944_refresh_cmd PAC1944 refresh command.

  void pac1944_refresh_cmd ( pac1944_t *ctx );

• pac1944_get_calc_measurement PAC1944 get calculated measurement function.

  float pac1944_get_calc_measurement ( pac1944_t *ctx, uint8_t meas_sel, uint8_t ch_sel, uint8_t avg_sel, uint8_t meas_mode );

Examples Description

This demo application shows an example of measuring voltage, current and power in a selected part of the circuit. Note that PAC1944 is a high side power monitor, therefore the desired channel should be connected accordingly.

The demo application is composed of two sections :

Application Init

Initialization of I2C module, log UART and additional pins. In addition, a default configuration is performed as followed:

• Sample mode is 1024, adaptive accumulation;
• INT pin is set as an alert;
• SLW pin is set as slow sampling rate control;
• All channels are on;
• Channel 1 is set for bipolar measurements;
• Channel 2 is set for bipolar measurements reduced by half;
• Channel 3 and 4 are set for unipolar measurements.

void application_init ( void ) {
    log_cfg_t log_cfg;  /**< Logger config object. */
    pac1944_cfg_t pac1944_cfg;  /**< Click config object. */

    /** 
     * Logger initialization.
     * Default baud rate: 115200
     * Default log level: LOG_LEVEL_DEBUG
     * @note If USB_UART_RX and USB_UART_TX 
     * are defined as HAL_PIN_NC, you will 
     * need to define them manually for log to work. 
     * See @b LOG_MAP_USB_UART macro definition for detailed explanation.
     */
    LOG_MAP_USB_UART( log_cfg );
    log_init( &logger, &log_cfg );
    log_info( &logger, " Application Init " );

    // Click initialization.

    pac1944_cfg_setup( &pac1944_cfg );
    PAC1944_MAP_MIKROBUS( pac1944_cfg, MIKROBUS_1 );
    err_t init_flag = pac1944_init( &pac1944, &pac1944_cfg );
    if ( init_flag == I2C_MASTER_ERROR ) {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }

    pac1944_device_state( &pac1944, PAC1944_DEV_ENABLE );
    Delay_ms ( 100 );
    pac1944_default_cfg ( &pac1944 );
    log_info( &logger, " Application Task " );
    log_printf( &logger, "-----------------------------\r\n" );
    Delay_ms ( 100 );
}

Application Task

The application sends a refresh command which stores the measurement data in registers. Measurements are acquired for voltage, current and power on channel 1 of PAC1944 Click board. The last 8 measurements are averaged and calculated in bipolar mode. Process is repeated every two seconds.

void application_task ( void ) {
    float voltage_sens;
    float current_sens;
    float power_sens;

    pac1944_refresh_cmd( &pac1944 );

    voltage_sens = pac1944_get_calc_measurement( &pac1944, PAC1944_MEAS_SEL_V_SOURCE,
                                                           PAC1944_CH_SEL_CH_1,
                                                           PAC1944_AVG_SEL_ENABLE,
                                                           PAC1944_MEAS_MODE_BIPOLAR_FSR );

    current_sens = pac1944_get_calc_measurement( &pac1944, PAC1944_MEAS_SEL_I_SENSE,
                                                           PAC1944_CH_SEL_CH_1,
                                                           PAC1944_AVG_SEL_ENABLE,
                                                           PAC1944_MEAS_MODE_BIPOLAR_FSR );

    power_sens = pac1944_get_calc_measurement( &pac1944,   PAC1944_MEAS_SEL_P_SENSE,
                                                           PAC1944_CH_SEL_CH_1,
                                                           PAC1944_AVG_SEL_ENABLE,
                                                           PAC1944_MEAS_MODE_BIPOLAR_FSR );


    log_printf( &logger, "  Voltage :  %.6f   V \r\n", voltage_sens );
    log_printf( &logger, "  Current :  %.6f   A \r\n", current_sens );
    log_printf( &logger, "  Power   :  %.6f   W \r\n", power_sens );
    log_printf( &logger, "-----------------------------\r\n" );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
}

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on mikroE github account.

Other mikroE Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.PAC1944

Additional notes and informations

Depending on the development board you are using, you may need USB UART Click, USB UART 2 Click or RS232 Click to connect to your PC, for development systems with no UART to USB interface available on the board. UART terminal is available in all Mikroelektronika compilers.