|
| 1 | +/* |
| 2 | + Modbus RTU Temeperature Sensor |
| 3 | +
|
| 4 | + This sketch show how to use the modbus library, in in order to sent a request to a slave RTU sensor |
| 5 | + unit and read the responce packet return by the remote unit. |
| 6 | +
|
| 7 | + Circuit: |
| 8 | + - MKR board |
| 9 | + - TModbus RS485 Temperature |
| 10 | + - MKR 485 shield |
| 11 | + - ISO GND connected to GND of the Modbus RTU server |
| 12 | + - Y connected to A/Y of the Modbus RTU sensor |
| 13 | + - Z connected to B/Z of the Modbus RTU sensor |
| 14 | + - Jumper positions |
| 15 | + - FULL set to OFF |
| 16 | + - Z \/\/ Y set to OFF |
| 17 | +
|
| 18 | + created 16 July 2018 |
| 19 | + by Sandeep Mistry |
| 20 | +*/ |
| 21 | + |
| 22 | +#include <ArduinoModbus.h> |
| 23 | + |
| 24 | +float temperature, humidity; |
| 25 | + |
| 26 | +void setup() { |
| 27 | + Serial.begin(9600); |
| 28 | + while (!Serial); |
| 29 | + |
| 30 | + Serial.println("Modbus Temperature Humidity Sensor"); |
| 31 | + // start the Modbus RTU client |
| 32 | + if (!ModbusRTUClient.begin(9600)) { |
| 33 | + Serial.println("Failed to start Modbus RTU Client!"); |
| 34 | + while (1); |
| 35 | + } |
| 36 | +} |
| 37 | + |
| 38 | +void loop() { |
| 39 | + //send a reading request to the RTU slave with id=1, type=HOLDING_REGISTERS address=0, number of values to read, nb=2 |
| 40 | + if (!ModbusRTUClient.requestFrom(1, HOLDING_REGISTERS, 0x00, 2)) { |
| 41 | + Serial.print("failed to read registers! "); |
| 42 | + Serial.println(ModbusRTUClient.lastError()); |
| 43 | + } else { |
| 44 | + //if the request goes fine read the value with the read() function |
| 45 | + short rawtemperature = ModbusRTUClient.read(); |
| 46 | + short rawhumidity = ModbusRTUClient.read(); |
| 47 | + temperature = rawtemperature / 10.0; |
| 48 | + humidity = rawhumidity / 10.0; |
| 49 | + Serial.println(temperature); |
| 50 | + Serial.println(humidity); |
| 51 | + } |
| 52 | + |
| 53 | + delay(5000); |
| 54 | +} |
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