Added T, RH readout

fw/Core/Inc/modbus.h

@@ -133,6 +133,8 @@ typedef struct {
 		uint16_t buffer16b[MODBUS_MAX_RTU_FRAME_SIZE/2];
 		uint16_t input_registers[MODBUS_MAX_REGISTERS];
 		uint16_t holding_registers[MODBUS_MAX_REGISTERS];
+		int16_t  input_registers_signed[MODBUS_MAX_REGISTERS];
+		int16_t  holding_registers_signed[MODBUS_MAX_REGISTERS];
 	};
 } modbus_transaction_t;
 

fw/Core/Src/main.c

@@ -51,7 +51,7 @@ const uint16_t tim21_prescaler = 60000-1; // 100Hz
 const uint16_t tim21_period = 1200-1; // 6s
 //const uint16_t tim21_period = 200-1; // 1s
 
-/* Input register memory map (just a suggestion, not implemented yet)
+/* Input register memory map
  * (All registers are 16-bit)
  * -------------------------
  *
@@ -63,40 +63,21 @@ const uint16_t tim21_period = 1200-1; // 6s
  * 30013 : T    [deg_C * 10] From SCD4x; unsigned value in range [0; 600]; e.g. 21.5 C => 215
  * 30014 : RH   [%]          From SCD4x; unsigned value in range [0; 100]
  *
- * Extended temperature range:
+ * Extended temperature range (signed values):
  * 30015 : T    [deg_C * 10] From SHT4x; signed value (two's complement) in range [-400;1250]
  * 30016 : T    [deg_C * 10] From SCD4x; signed value (two's complement) in range [-100;600]; e.g. -12.3 C => -123
  *
- *
- * Notes:
- *
- *  - je potreba uzivateli zpristupnit T a RH z SCD4x? Pripadne je tam nechat, ale pouze jako zalozni?
- *  - jaky pouzit format pro signed hodnoty? Two's complement (int16_t)? Nebo jich tam dat vic (one's complement)?
- *  - omezit rozsah? Pro mereni T v interieru nema smysl +125 deg C (na to uz jsou pozarni cidla, haha)
- *  - pocatecni cislo registru (30010) jsem si vymyslel. Muzeme pouzit jine, treba primo zacatek input registru (30001)
- *
  */
 /* Input registers memory map implementation */
-union {
+enum {
-	struct {
+	REGISTER_NUM_CO2 = 30010,
-		uint16_t CO2;			 // 30010
+	REGISTER_NUM_T_SHT4x = 30011,
-		uint16_t T_SHT4x;		 // 30011
+	REGISTER_NUM_RH_SHT4x = 30012,
-		uint16_t RH_SHT4x;		 // 30012
+	REGISTER_NUM_T_SCD4x = 30013,
-		uint16_t T_SCD4x;		 // 30013
+	REGISTER_NUM_RH_SCD4x = 30014,
-		uint16_t RH_SCD4x;		 // 30014
+	REGISTER_NUM_T_SHT4x_SIGNED = 30015,
-		int16_t  T_SHT4x_signed; // 30015
+	REGISTER_NUM_T_SCD4x_SIGNED = 30016
-		int16_t  T_SCD4x_signed; // 30016
+} register_numbers;
-	};
-	struct {
-		uint16_t main_values[3];			// CO2, T_SHT4x, RH_SHT4x
-		uint16_t backup_values[2];			// T_SCD4x, RH_SCD4x
-		int16_t  extended_range_values[2];	// T_SHT4x_signed, T_SCD4x_signed
-	};
-	struct {
-		uint16_t unsigned_values[5];
-		int16_t  signed_values[2];
-	};
-} measured_values;
 
 /* Variables to store the measured data */
 int CO2, T_SCD4x, RH_SCD4x;
@@ -118,14 +99,38 @@ void LPUART1_TX_Buffer(uint8_t* buffer_tx, uint8_t buffer_tx_len);
 /* USER CODE BEGIN 0 */
 int8_t modbus_slave_callback(modbus_transaction_t *transaction)
 {
+	uint16_t register_number = transaction->register_number;
 	if (transaction->function_code == MODBUS_READ_INPUT_REGISTERS) {
-		// TODO select reasonable register numbers and implement
+		for (int i = 0; i < transaction->register_count; i++, register_number++) {
-		// readout of all measured variables
+			switch (register_number) {
-		if (transaction->register_number == 30010) { // register number 30010 (randomly selected)
+			case REGISTER_NUM_CO2:
-			transaction->input_registers[0] = CO2;
+				transaction->input_registers[i] = (uint16_t)CO2;
-			return MODBUS_OK;
+				break;
+			case REGISTER_NUM_T_SHT4x:
+				transaction->input_registers[i] = (uint16_t)T_SHT4x;
+				break;
+			case REGISTER_NUM_RH_SHT4x:
+				transaction->input_registers[i] = (uint16_t)RH_SHT4x;
+				break;
+			case REGISTER_NUM_T_SCD4x:
+				transaction->input_registers[i] = (uint16_t)T_SCD4x;
+				break;
+			case REGISTER_NUM_RH_SCD4x:
+				transaction->input_registers[i] = (uint16_t)RH_SCD4x;
+				break;
+			case REGISTER_NUM_T_SHT4x_SIGNED:
+				transaction->input_registers_signed[i] = (int16_t)T_SHT4x;
+				break;
+			case REGISTER_NUM_T_SCD4x_SIGNED:
+				transaction->input_registers_signed[i] = (int16_t)T_SCD4x;
+				break;
+			default:
+				return MODBUS_ERROR_FUNCTION_NOT_IMPLEMENTED;
+			}
 		}
+		return MODBUS_OK;
 	}
+	/* Catch-all error */
 	return MODBUS_ERROR_FUNCTION_NOT_IMPLEMENTED; /* nothing implemented yet! TODO */
 }
 

tests/minimalmodbus_test.py

@@ -1,4 +1,5 @@
 #!/usr/bin/env python3
+from time import sleep
 import minimalmodbus
 import serial
 
@@ -14,5 +15,11 @@ instrument.mode = minimalmodbus.MODE_RTU   # rtu or ascii mode
 instrument.clear_buffers_before_each_transaction = True
 
 # read
+T = 0
+RH = T
 CO2 = instrument.read_register(9, 1, functioncode=4) * 10
-print(CO2)
+sleep(0.1)
+T = instrument.read_register(10, 1, functioncode=4)
+sleep(0.1)
+RH = instrument.read_register(11, 1, functioncode=4) * 10
+print(f'CO2: {CO2} ppm\t\tT: {T} deg C\t\tRH: {RH} %')