feat: get capacitor range

Author: CloudyPadmal

src/commands.c

@@ -252,7 +252,7 @@ command_func_t* const cmd_table[NUM_PRIMARY_CMDS + 1][NUM_SECONDARY_CMDS_MAX + 1
      // 12 READ_PROGRAM_ADDRESS         13 WRITE_PROGRAM_ADDRESS        14 READ_DATA_ADDRESS            15 WRITE_DATA_ADDRESS
         Removed,                        Removed,                        DEVICE_ReadRegisterData,        DEVICE_WriteRegisterData,
      // 16 GET_CAP_RANGE                17 SET_RGB2                     18 READ_LOG                     19 RESTORE_STANDALONE
-        Unimplemented,                  Removed,                        Removed,                        DEVICE_Reset,
+        MULTIMETER_GetCapRange,         Removed,                        Removed,                        DEVICE_Reset,
      // 20 GET_ALTERNATE_HIGH_FREQUENCY 21 SET_RGB_COMMON               22 SET_RGB3                     23 START_CTMU
         Unimplemented,                  LIGHT_RGBPin,                   Removed,                        CTMU_Start,
      // 24 STOP_CTMU                    25 START_COUNTING               26 FETCH_COUNT                  27 FILL_BUFFER

src/instruments/multimeter.c

@@ -16,6 +16,7 @@ void ChargeCapacitor(uint8_t charge, uint16_t period);
 void GetCapacitance_InitCTMU_TMR5(uint8_t current_range, uint8_t trim,
         uint16_t charge_time);
 void GetCapacitance_ConfigADC_CTMU_TMR5();
+void GetCapacitor_Range(uint16_t charge_time);
 
 void ChargeCapacitor(uint8_t charge, uint16_t period) {
     CAP_OUT_SetDigitalOutput();
@@ -95,6 +96,33 @@ uint16_t GetVoltage_Summed(uint8_t channel) {
     return voltage_sum;
 }
 
+uint16_t GetCapacitor_Range(uint16_t charge_time) {
+
+    ChargeCapacitor(0, 50000);
+    ChargeCapacitor(0, 50000); // TODO: Check if we need two of these
+
+    ADC1_SetOperationMode(ADC1_12BIT_AVERAGING_MODE, CH0_CHANNEL_CAP, 0);
+
+    TMR5_Initialize();
+    TMR5_Period16BitSet(charge_time);
+    TMR5_SetPrescaler(TMR_PRESCALER_64);
+    TMR5_Start();
+
+    // Start charging the capacitor through 10K resistor
+    CAP_OUT_SetDigitalOutput();
+    CAP_OUT_SetHigh();
+
+    TMR5_WaitForInterruptEvent();
+
+    // Stop the charging process
+    CAP_OUT_SetDigitalInput();
+    CAP_OUT_SetLow();
+
+    uint16_t total = GetVoltage_Summed(CH0_CHANNEL_CAP);
+
+    return total;
+}
+
 response_t MULTIMETER_GetVoltage(void) {
 
     uint8_t channel = UART1_Read();
@@ -193,6 +221,16 @@ response_t MULTIMETER_GetCapacitance(void) {
     return SUCCESS;
 }
 
+response_t MULTIMETER_GetCapRange(void) {
+
+    uint16_t charge_time = UART1_ReadInt(); // in microseconds
+
+    uint16_t range = GetCapacitor_Range(charge_time);
+    UART1_WriteInt(range);
+
+    return SUCCESS;
+}
+
 response_t MULTIMETER_GetCTMUVolts(void) {
 
     uint8_t config = UART1_Read();

src/instruments/multimeter.h

@@ -28,6 +28,19 @@ extern "C" {
      * @return SUCCESS
      */
     response_t MULTIMETER_GetCapacitance(void);
+
+    /**
+     * @brief Get an estimate of the capacitor range
+     *
+     * @description
+     * This command takes only one argument over serial:
+     * 1. (uint16) Charge time
+     *
+     * It returns the range value as uint16.
+     *
+     * @return SUCCESS
+     */
+    response_t MULTIMETER_GetCapRange(void);
 
     /**
      * @brief Measurements using Charge Time Measurement Unit