new FCs

Author: bertmelis

Diff for: README.md

@@ -6,27 +6,13 @@
 
 - it is working
 - only RS485 half duplex using a GPIO as RTS (DE/RS) is implemented
-- only function code 04 is implemented (others will be there soon)
+- function codes implemented:
+  - read discrete inputs (02)
+  - read holding registers (03)
+  - read input registers (04)
 - async operation. blocking code is in a seperate task
 - error codes are implemented but untested (somehow my device just tries to answer all the time instead of generating a Modbus error)
 
-To add new function codes:
-- create class, inherit from `ModbusRequest`
-- the constructor needs to get all the needed data as arguments
-- in the constructor
-  - call `ModbusRequest(size_t)` in the initializer list with the needed message length as argument
-  - create the modbus request by sequentially call `add(uint8_t)` to add a byte to the message buffer
-  (first byte first, so start with the slave address)
-- add a (virtual) method:
-
-  ```C++
-  ModbusResponse* ModbusRequestType::makeResponse() {
-    uint8_t responseLength = 3 + (_byteCount * 2) + 2;  // expected length in the response
-    ModbusResponse* response = new ModbusResponse(responseLength, this);
-    return response;
-  }
-  ```
-Note: the response will be deleted elsewhere.
 
 # Example hardware:
 

Diff for: examples/SDM630/SDM630.ino

@@ -39,6 +39,6 @@ void loop() {
   if (millis() - lastMillis > 30000) {
     lastMillis = millis();
     Serial.print("sending Modbus request...\n");
-    modbus.readInputRegister(0x01, 52, 2);
+    modbus.readInputRegisters(0x01, 52, 2);
   }
 }