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mattallen37 wrote:I know the RS485 library should work, but I haven't run either of these test programs for a while.

NXC RS485 library

Code: Select all

/*
*  Matthew Richardson
*  matthewrichardson37<at>gmail.com
*  http://mattallen37.wordpress.com/
*  Aug. 11 / 2012
*
*  You may use this code as you wish, provided you give credit where it's due.
*
*  This is library for easy use of RS485 master/slave transactions.
*/

/*
My RS485 protocol data specs:

Sending byte array looks like this (based on how Mark Crosby does it) :
  
byte   type         description
0      MSG_TYPE     The type of message.
1      BYTE_COUNT   The count of bytes in the message body, excluding the header.
2      CHECKSUM     CRC8 checksum computed across the message body.
3      DEST_ADDR    Destination address for the message, or 0 for BROADCAST.
4      SRC_ADDR     Source address of the message sender.
5-n    The data

Returned values

-6 wrong message length
-5 wrong checksum
-4 not even the entire header was received
-3 not my address
-2 timeout
-1 something went wrong
0  Destination address was BROADCAST
1  Destination address was mine

*/

#ifndef _MyRS485Base_h_
#define _MyRS485Base_h_

void MyRS485BaseWriteArray (byte My485Address, byte TargetAddress, byte MsgType, byte SendData[], byte Length = 0){

  byte ByteCount = ArrayLen(SendData);

  if(Length){
    ByteCount = Length;
  }

  byte SendCompleteData[];
  byte SendCompleteDataLength = ByteCount + 5;
  ArrayInit(SendCompleteData, 0, SendCompleteDataLength);

  SendCompleteData[0] = MsgType;
  SendCompleteData[1] = ByteCount;
  SendCompleteData[2] = ArraySum(SendData, NA, ByteCount) & 0xFF;
  SendCompleteData[3] = TargetAddress;
  SendCompleteData[4] = My485Address;
  
  for(byte i = 0; i < ByteCount; i++){
    SendCompleteData[i + 5] = SendData[i];
  }

  RS485Write(SendCompleteData);
  until(HSOutputBufferOutPtr() == SendCompleteDataLength);
}

int MyRS485BaseRead(byte My485Address, byte & MsgType, byte & InArray[], int timeout = 250){
  byte RawInArray[];

  long OrigionalTick = CurrentTick();
  until(RS485DataAvailable()){                                                  // Wait until data has been received
    if(timeout && (CurrentTick() - OrigionalTick >= timeout))return -2;         // return -2 if it timed-out waiting for the responce.
    Yield();
  }
  byte DataAvailable = RS485DataAvailable();
  Wait(1);
  while(DataAvailable < RS485DataAvailable()){                                  // If it's been 1 ms since the last data was received, assume it's the end of the message.
    DataAvailable = RS485DataAvailable();
    Wait(1);
  }
  RS485Read(RawInArray);

  if(DataAvailable < 5)return -4;                                               // Not even the entire header was received.
  
  MsgType        = RawInArray[0];
  byte ByteCount = RawInArray[1];
  byte Checksum  = RawInArray[2];
  byte DestAddr  = RawInArray[3];
  byte SrcAddr   = RawInArray[4];

  if (DestAddr == My485Address || DestAddr == 0)
  {

    if(ByteCount != DataAvailable - 5){
      return -6;
    }

    byte ChecksumComputed = ArraySum(RawInArray, 5, NA) & 0xFF;
    if(Checksum != ChecksumComputed){
      return -5;
    }
    
    ArraySubset(InArray, RawInArray, 5, NA);
    
    return DestAddr?1:0;
  }
  else{
    return -3;
  }
  return -1;
}

void RS485Init(byte speed = HS_BAUD_921600)      // Turn on RS485 and set a baud rate
{
  UseRS485();
  Wait(MS_10);
  SetHSDataMode(DATA_MODE_RAW);
  Wait(MS_10);
  RS485Uart(speed, HS_MODE_DEFAULT);
  Wait(MS_10);
  SetHSInputBufferInPtr(0);
  SetHSInputBufferOutPtr(0);
}

void RS485UnInit(){                              // Turn off the RS485 port of the NXT
  SetSensorType(S4, SENSOR_TYPE_NONE);
  SetHSFlags(HS_UPDATE);
  SetSensorType(S4, SENSOR_TYPE_NONE);
}

#endif

rx test program

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#include "MyRS485Base lib.nxc"

byte Array[];
byte MsgType;

task main(){

  RS485Init(HS_BAUD_115200);

  while(true){
    //NumOut(0, LCD_LINE5, MyRS485BaseRead(2, MsgType, Array, 100));
    int result = MyRS485BaseRead(2, MsgType, Array, 100);
    ClearScreen();
    NumOut(0, LCD_LINE1, result);
    if(result >= 0){
      NumOut(0, LCD_LINE2, MsgType);
      for(byte i = 0; i < ArrayLen(Array); i ++){
        NumOut(50, LCD_LINE1 - (i*8), Array[i]);
      }
    }
  }
}

tx test program

Code: Select all

#include "MyRS485Base lib.nxc"

byte Array[6];
byte MsgType;
byte b1, b2, lx, ly, rx, ry;

task main(){

  RS485Init(HS_BAUD_115200);

  SetSensorLowspeed(S3);
  
  while(true){
  
    ReadSensorMSPlayStation(S3, 0x02, b1, b2, lx, ly, rx, ry);
    Array[0] = b1;
    Array[1] = b2;
    Array[2] = lx;
    Array[3] = ly;
    Array[4] = rx;
    Array[5] = ry;

    MsgType = ButtonPressed(BTNCENTER)?2:0;

    MyRS485BaseWriteArray(1, 2, MsgType, Array);
    
    Wait(10);
  }
}

RemoteSetSensor(RS, 2, S1, SENSOR_TOUCH); // via RS485: config at NXT #2: Touch sensor at S1
RemoteSetSensor(RS, 10, S2, SENSOR_US);  // via RS485: config at NXT #10: US sensor at S2
RemoteSetSensor(RS, 4, S3, SENSOR_RAW);  // via RS485: config at NXT #4: analog sensor (ADC raw) at S3

int x=RemoteSensorTouch(RS, 2, S1);       // via rs485: read at NXT #2: Touch Sensor value at S1
int x=RemoteSensorUS(RS, 10, S2);         // via rs485: read at NXT #10: US Sensor value at S2
int x=RemoteSensorRaw(RS, 4, S3);         // via rs485: read at NXT #4: analog sensor value (ADC raw) at S3


RemoteOnFwd(RS, 3, OUT_A, pwr);             // via rs485: onFwd at NXT #3: OUT_A by pwr
RemoteOnFwdReg(RS, 5, OUT_B, pwr, regmode); // via rs485: onFwdReg at NXT #5: OUT_B by pwr, regmode

long e=RemoteMotRotCounter(RS, 9, OUT_C);   // via rs485: at NXT #9: read motor rotation counter of OUT_C