DAS1612.mpas

program DAS1612;
{ Declarations section }
// DAS1612 acquisition program
// PIC16F73 controls an AD574 acquisition board
// get acquisition parameters from a config. string
// output data in +/- 5000 or 10000 mV
// I/O CONFIGURATION:
// DIP baud-rate   input   A2,A3      0..4: 9600,19200,57600,115200
// ADC CFS         output  A4         Lo: +/-5V, Hi: +/-10V FS
// LED ACQ         output  A5         Hi: ON
// MPX address   output    C0,C3
// ADC data bus   input    B0,B7
// ADC EOC        input    A0         Hi->Lo: End Of Conversion
// ADC STR        output   C4         Hi->Lo->Hi: Start Of Conversion
// ADC CA0(Hi/Lo) output   C5         Lo: ADC MS byte, Hi: ADC LS digit
// start buttton  input    A1         Lo: Start
// Serial Tx      output   C6
// Serial Rx      input    C7
// MCU Xtal: 18.432 MHz
// New version - G. Carrera 26/06/2016

const
  CR: char = 13;
  LF: char = 10;
var
  b,chin,chfi,BPm,baud,FS,ic,temp: byte;
  Ns,sc,ts,ttx,tscan: word;
  cf: real;
  sigdata: integer;
  cis,cfs,Rs,Tms: string[3];
  NSs,tx6: string[6];
  int0flg,err: boolean;

procedure interrupt;
// timer#0 for interrupt every 1 msec (1000Hz)
begin
  if TestBit(INTCON, T0IF) then  // timer#0 interrupt
    begin
      ClearBit(INTCON, T0IF); // reset Timer#0 interrupt flag
      TMR0:= 238;
      SetBit(INTCON, T0IE); // Enables Timer#0 interrupt
      int0flg:= true;
    end;
end;

procedure IOinit;
// initialize I/O
begin
  PORTA:=0; // ACQ LED off, +/-5V FS
  ADCON1:=$06;{PortA : Digital I/O}
  TRISA:= $CF;{PORTA bits 4,5 are outputs}
  TRISC:= $80;{PORTC bits 0..6 are outputs}
  {PortB is 8 bit inputs}
  ClearBit(PORTC, 5);  // Clear CA0
  SetBit(PORTC, 4);  // ADC Strobe = Hi
  baud:= (PORTA And $0C) Shr 2; {read  baud rate DIP}
  case baud of
    0: UART1_Init(9600);
    1: UART1_Init(19200);
    2: UART1_Init(57600);
    3: UART1_Init(115200);
  end;
  OPTION_REG:= $07;{set prescaler of Timer#0 to 256,PB pull-up disabled}
  TMR0:= 238; // T0 overflow every 18 counts
  SetBit(INTCON, T0IE); // Enables Timer#0 interrupt
  ClearBit(INTCON, T0IF); // reset Timer#0 interrupt flag
  SetBit(INTCON, GIE); // Enables global interrupt
  int0flg:= false;
end;

function GetByte: char;
// get a byte from UART1 and convert in upper case
begin
  if UART1_Data_Ready() = 1 then
    begin
      result:= UART1_Read;
      if (result>=$61) And (result<$7B) then result:= result-$20; {Upper Case convert}
    end;
end;


begin  { Main program }
  IOinit;
  UART1_Write_Text('DAS1612 serial acquisition system'+CR+LF);
  UART1_Write_Text('Cfg string: $ci,cf,BPm,ns,fs*'+CR+LF);
  UART1_Write_Text('Base Period is 1 [ms]'+CR+LF);
  UART1_Write_Text('G.Carrera -- rev. 26/06/16'+CR+LF);
   repeat  {get acquisition configuration string}
    UART1_Write_Text('Waiting for configuration string..'+CR+LF);
    {get configuration string: $ci,cf,BPm,ns,fs* ,Base Period = 10ms}
    repeat until GetByte='$'; {wait for configuration string}
    err:= false;
    //read the configuration parameters
    UART1_Read_Text(cis,',',3); {read start channel}
    UART1_Read_Text(cfs,',',3); {read last channel}
    UART1_Read_Text(Tms,',',10); {read Base Period multiplier}
    UART1_Read_Text(NSs,',',10); {read Number of samples }
    UART1_Read_Text(Rs,'*',3); {read ADC Full Scale}
    // convert in numerical format
    chin:= byte(StrToInt(cis));
    chfi:= byte(StrToInt(cfs));
    BPm:= byte(StrToInt(Tms));
    Ns:= StrToWord(NSs);
    FS:= byte(StrToInt(Rs));
    // now controls parameters
    if (chin>15) or (chfi>15) or (chin>chfi) then err:= true;
    if (BPm=0) or (NS=0) then err:= true;
    if (FS=5) then ClearBit(PORTA, 4)  {+/-5V}
    else if (FS=10) then SetBit(PORTA, 4) {+/-10V}
    else err:= true; {errors on config string}
    if err then UART1_Write_Text('Errors on configuration string !!'+CR+LF);
    //PeriodVerify;
    
    b:= (chfi-chin+1)*6+2;{number of characters to transmit}
    ts:= BPm*1000; {sample period in micros}
    tscan:= (chfi-chin+1)*25; {scan time in microseconds}
    case baud of  {transmit time in microseconds}
      0: ttx:= 1042*b;
      1: ttx:= 521*b;
      2: ttx:= 174*b;
      3: ttx:= 87*b;
    end;
    if ((tscan+ttx) > ts) then
      begin
        UART1_Write_Text('Ts is incompatible with baud rate !!'+CR+LF);
        WordToStr(word(tscan+ttx), tx6);
        UART1_Write_Text('Ts must be greater than '+tx6+' [us]'+CR+LF);
        err:= true;
      end;
   until err=0;
   // print acquisition parameters
   UART1_Write_Text(CR+LF);
   UART1_Write_Text('Initial Ch = '+cis+', Final Ch = '+cfs+', +/- F.S. [V] = '+Rs+CR+LF);
   UART1_Write_Text('Ts [ms] = '+Tms+', Samples = '+NSs+CR+LF);
   cf:= FS*1000/2047; // mV conversion factor
  while true Do //  endless loop
    begin
      UART1_Write_Text('Push Start Button or write A to start'+CR+LF);
      repeat until (GetByte='A') Or (TestBit(PORTA, 1)=0);
      ic:=0;
      UART1_Write_Text(CR+LF);
      SetBit(PORTA, 5);  // LED on
      UART1_Write_Text('DATA'+CR+LF);
      ic:=0; sc:=0;
      while sc<ns Do
        begin
          if int0flg then
             begin
               int0flg:= false;
               ic:=ic+1; {counts periods of 10ms}
             end;
          if (ic= BPm) then
            begin {scan every sample period}
              ic:=0;
              b:= chin;
              for b:= chin to chfi  do
                begin {scan channels and transmit}
                  PORTC:= (PORTC And $F0) + b; // set channel address
                  Delay_us(2);
                  ClearBit(PORTC, 4);{ADC Strobe = Lo}
                  SetBit(PORTC, 4);{ADC Strobe = Hi}
                  repeat until TestBit(PORTA, 0);{wait for /EOC going Hi}
                  repeat until (TestBit(PORTA, 0)=0);{wait for /EOC going Lo}
                  sigdata:= PORTB shl 4;{shift MS byte}
                  SetBit(PORTC, 5);{CA0=Hi -> LS digit}
                  temp:= PORTB shr 4; {shift LS digit}
                  ClearBit(PORTC, 5);  // Clear CA0
                  {assemble and convert data from offset binary code}
                  sigdata:= (sigdata or integer(temp))-2048;
                  sigdata:= integer(sigdata*cf);{convert in mV}
                  IntToStr(sigdata,tx6);
                  UART1_Write_Text(tx6);{now transmit data}
                end;
              UART1_Write_Text(CR+LF);
              sc:=sc+1; {increment sample counter}
            end; {end of scan loop}
        end; {end of acquisition loop}
        ClearBit(PORTA, 5);  // LED off
    end;{end of endless loop}
end.