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Ad7734 Channel assignment and ADC overload behavior #5

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016b145
overloading input converts to +-10 instead of 0
zibrov-zlobin Jun 12, 2018
1b7a00d
ad7734-ad5764 simple channel assignment/ changed ADC overload behaviour
zibrov-zlobin Jun 13, 2018
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115 changes: 60 additions & 55 deletions AD7734_AD5764/AD7734_AD5764.ino
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Original file line number Diff line number Diff line change
Expand Up @@ -17,6 +17,9 @@ int delayUnit=0; // 0=microseconds 1=miliseconds

float DAC_FULL_SCALE = 10;

int chDAC[4] = {0, 1, 2, 3}; // change to reassign the port numbers
int chADC[4] = {0, 1, 2, 3}; // change to reassign the port numbers

// Calibration constans
float OS[4]={0,0,0,0}; // offset error
float GE[4]={1,1,1,1}; // gain error
Expand Down Expand Up @@ -137,16 +140,16 @@ void writeADCConversionTime(std::vector<String> DB)
int adcChannel;
switch(DB[1].toInt()){
case 0:
adcChannel = 0;
adcChannel = chADC[0];
break;
case 1:
adcChannel = 1;
adcChannel = chADC[1];
break;
case 2:
adcChannel = 2;
adcChannel = chADC[2];
break;
case 3:
adcChannel = 3;
adcChannel = chADC[3];
break;

default:
Expand Down Expand Up @@ -229,7 +232,8 @@ float getSingleReading(int adcchan)
int statusbyte=0;
byte o2;
byte o3;
int ovr;
int ovr, sign;
float voltage;
if(adcchan <= 3)
{
SPI.transfer(adc,0x38+adcchan); // Indicates comm register to access mode register with channel
Expand All @@ -239,21 +243,20 @@ float getSingleReading(int adcchan)
statusbyte=SPI.transfer(adc,0); // Reads Channel 'ch' status
o2=SPI.transfer(adc,0); // Reads first byte
o3=SPI.transfer(adc,0); // Reads second byte
ovr=statusbyte&1;
switch (ovr)
{
case 0:
int decimal;
decimal = twoByteToInt(o2,o3);
float voltage;
voltage = map2(decimal, 0, 65536, -10.0, 10.0);
ovr = statusbyte & 1; // select bit0 of channel status register - over or underrange of analog input
sign = statusbyte & 2; // select bi1 of channel status register - voltage polarity of analog input

if(ovr)
{
if (sign){ voltage = 10.0;
} else {
voltage = -10.0;
}
} else {
int decimal = twoByteToInt(o2,o3);
voltage = map2(decimal, 0, 65536, -10.0, 10.0);
}
return voltage;
break;

case 1:
return 0.0;
break;
}
}
}

Expand All @@ -263,16 +266,16 @@ float readADC(byte DB)
switch (adcChannel)
{
case 0:
return getSingleReading(0);
return getSingleReading(chADC[0]);
break;
case 1:
return getSingleReading(1);
return getSingleReading(chADC[1]);
break;
case 2:
return getSingleReading(2);
return getSingleReading(chADC[2]);
break;
case 3:
return getSingleReading(3);
return getSingleReading(chADC[3]);
break;

default:
Expand Down Expand Up @@ -305,19 +308,19 @@ float writeDAC(int dacChannel, float voltage)
switch(dacChannel)
{
case 0:
return dacDataSend(dacChannel,voltage/GE[0]-OS[0]);
return dacDataSend(chDAC[0],voltage/GE[0]-OS[0]);
break;

case 1:
return dacDataSend(dacChannel,voltage/GE[1]-OS[1]);
return dacDataSend(chDAC[1],voltage/GE[1]-OS[1]);
break;

case 2:
return dacDataSend(dacChannel,voltage/GE[2]-OS[2]);
return dacDataSend(chDAC[2],voltage/GE[2]-OS[2]);
break;

case 3:
return dacDataSend(dacChannel,voltage/GE[3]-OS[3]);
return dacDataSend(chDAC[3],voltage/GE[3]-OS[3]);
break;

default:
Expand All @@ -329,12 +332,13 @@ void readingRampAvg(int adcchan, byte b1, byte b2, byte * o1, byte * o2,int coun
{
Serial.flush();
int statusbyte=0;
int ovr;
int ovr, sign;
byte db1;
byte db2;
float sum=0;
float avg;
bool toSend = true;
float voltage;
if(adcchan <= 3)
{
for(int i = 1; i<=nReadings; i++)
Expand All @@ -352,26 +356,27 @@ void readingRampAvg(int adcchan, byte b1, byte b2, byte * o1, byte * o2,int coun
statusbyte=SPI.transfer(adc,0); // Reads Channel 'ch' status
db1=SPI.transfer(adc,0); // Reads first byte
db2=SPI.transfer(adc,0); // Reads second byte
ovr=statusbyte&1;
if (ovr){break;}
int decimal = twoByteToInt(db1,db2);
float voltage = map2(decimal, 0, 65536, -10.0, 10.0);
ovr = statusbyte&1;
sign = statusbyte & 2; // select bi1 of channel status register - voltage polarity of analog input
if(ovr)
{
if (sign){ voltage = 10.0;
} else {
voltage = -10.0;
}
} else {
int decimal = twoByteToInt(db1,db2);
voltage = map2(decimal, 0, 65536, -10.0, 10.0);
}
sum += voltage;
}
if(ovr)
{
*o1=128;
*o2=0;
}
else
{
avg = sum/nReadings;
int decimal = map2(avg, -10.0, 10.0, 0, 65536);
intToTwoByte(decimal, &db1, &db2);
*o1=db1;
*o2=db2;
}
}

avg = sum/nReadings;
int decimal = map2(avg, -10.0, 10.0, 0, 65536);
intToTwoByte(decimal, &db1, &db2);
*o1=db1;
*o2=db2;
}
}

void rampRead(byte DB,byte b1, byte b2, byte * o1, byte * o2, int count,int nReadings )
Expand All @@ -380,19 +385,19 @@ void rampRead(byte DB,byte b1, byte b2, byte * o1, byte * o2, int count,int nRea
switch (adcChannel)
{
case 0:
readingRampAvg(0, b1 , b2, o1, o2,count,nReadings);
readingRampAvg(chADC[0], b1 , b2, o1, o2,count,nReadings);
break;

case 1:
readingRampAvg(1, b1 , b2, o1, o2,count,nReadings);
readingRampAvg(chADC[1], b1 , b2, o1, o2,count,nReadings);
break;

case 2:
readingRampAvg(2, b1 , b2, o1, o2,count,nReadings);
readingRampAvg(chADC[3], b1 , b2, o1, o2,count,nReadings);
break;

case 3:
readingRampAvg(3, b1 , b2, o1, o2,count,nReadings);
readingRampAvg(chADC[4], b1 , b2, o1, o2,count,nReadings);
break;

default:
Expand Down Expand Up @@ -421,19 +426,19 @@ float writeDAC_buffer(int dacChannel, float voltage)
switch(dacChannel)
{
case 0:
return dacDataSend_buffer(dacChannel,voltage/GE[0]-OS[0]);
return dacDataSend_buffer(chDAC[0],voltage/GE[0]-OS[0]);
break;

case 1:
return dacDataSend_buffer(dacChannel,voltage/GE[1]-OS[1]);
return dacDataSend_buffer(chDAC[1],voltage/GE[1]-OS[1]);
break;

case 2:
return dacDataSend_buffer(dacChannel,voltage/GE[2]-OS[2]);
return dacDataSend_buffer(chDAC[2],voltage/GE[2]-OS[2]);
break;

case 3:
return dacDataSend_buffer(dacChannel,voltage/GE[3]-OS[3]);
return dacDataSend_buffer(chDAC[3],voltage/GE[3]-OS[3]);
break;

default:
Expand Down Expand Up @@ -868,4 +873,4 @@ void loop()
comm = query_serial();
router(comm);
}
}
}