manchoz_fix_rs485 (#52)

* Fix endTrasmission timings

* Fix RS485 Full Duplex support

* Update RS485 example

* Update supported architectures

Author: manchoz

examples/RS485_fullduplex/RS485_fullduplex.ino

@@ -19,43 +19,49 @@ using namespace machinecontrol;
 
 unsigned long counter = 0;
 
-void setup() {
-
-  Serial.begin(9600);
-  while (!Serial) {
-    ; // wait for serial port to connect.
-  }
-  Serial.println("Start RS485 initialization");
-
-  // Initialize the serial interface, enable the 
-  // RS485 on SP335ECR1 and set as full duplex 
-  comm_protocols.rs485.begin(9600);
-  comm_protocols.rs485.enable = 1;
-  comm_protocols.rs485.sel_485 = 1;
-  comm_protocols.rs485.half_duplex = 0;
-
-  Serial.println("Initialization done!");
+void setup()
+{
+
+    Serial.begin(115200);
+    while (!Serial) {
+        ; // wait for serial port to connect.
+    }
+    delay(1000);
+    Serial.println("Start RS485 initialization");
+
+    comm_protocols.rs485.begin(115200);
+    comm_protocols.rs485.enable = 1;        // SDHN_N
+    comm_protocols.rs485.sel_485 = 1;       // RS485_RS232_N
+    comm_protocols.rs485.half_duplex = 0;   // HALF_FULL_N
+    comm_protocols.rs485.receive();         // RE_N
+    comm_protocols.rs485.fd_tx_term = 1;    // FD_TX_TERM - 120 Ohm Y-Z termination enabled when both TERM and FD_TX_TERM are high
+    comm_protocols.rs485.term = 1;          // TERM - 120 Ohm A-B termination enabled when high
+
+    Serial.println("Initialization done!");
 }
 
+constexpr unsigned long sendInterval { 1000 };
+unsigned long sendNow { 0 };
+
+constexpr unsigned long halfFullInterval { 5000 };
+unsigned long halfFull { 0 };
+byte halfFullStatus { 0 };
+
+void loop()
+{
+    while (comm_protocols.rs485.available())
+        Serial.write(comm_protocols.rs485.read());
+
+    if (millis() > sendNow) {
+        comm_protocols.rs485.noReceive();
+        comm_protocols.rs485.beginTransmission();
+
+        comm_protocols.rs485.print("hello ");
+        comm_protocols.rs485.println(counter++);
+
+        comm_protocols.rs485.endTransmission();
+        comm_protocols.rs485.receive();
 
-void loop() {
-  // Call receive(); sets the flux control pins properly
-  // and allows receiving data if available
-  comm_protocols.rs485.receive();
-  if (comm_protocols.rs485.available()) {
-    Serial.print("read byte: ");
-    Serial.write(comm_protocols.rs485.read());
-    Serial.println();
-  }
-  // Call beginTransmission(); sets the flux control pins properly
-  // and allows starting a trasnsmission.
-  // If instead of a string, you want
-  // to send bytes, use the API write();
-  comm_protocols.rs485.beginTransmission();
-  comm_protocols.rs485.print("hello ");
-  comm_protocols.rs485.println(counter);
-  comm_protocols.rs485.endTransmission();
-  counter++;
-
-  delay(1000);
+        sendNow = millis() + sendInterval;
+    }
 }

library.properties

@@ -6,5 +6,5 @@ sentence=Arduino Library for Arduino Machine Control
 paragraph=
 category=Communication
 url=https://github.com/arduino-libraries/MachineControl
-architectures=mbed
+architectures=mbed, mbed_portenta
 includes=MachineControl.h

src/utility/RS485/RS485.cpp

@@ -50,6 +50,8 @@ void RS485Class::begin(unsigned long baudrate, uint16_t config)
 
   _transmisionBegun = false;
 
+  half_duplex.output();
+
   _serial->begin(baudrate, config);
 }
 
@@ -123,7 +125,7 @@ void RS485Class::endTransmission()
   _serial->flush();
 
   if (_dePin != NC) {
-    delayMicroseconds(50);
+    delayMicroseconds(500);
     digitalWrite(_dePin, LOW);
   }
 

src/utility/RS485/RS485.h

@@ -50,7 +50,7 @@ class RS485Class : public HardwareSerial {
 
     void setPins(PinName txPin, PinName dePin, PinName rePin);
 
-    mbed::DigitalOut half_duplex = mbed::DigitalOut(PA_9);
+    mbed::DigitalInOut half_duplex = mbed::DigitalInOut(PA_9);
     mbed::DigitalOut sel_485 = mbed::DigitalOut(PA_10);
     mbed::DigitalOut slew_n = mbed::DigitalOut(PG_14);
     mbed::DigitalOut fd_tx_term = mbed::DigitalOut(PI_15);