by the way: the used board is a MEGA
// set up the speed, data order and data mode
SPISettings settingsA(2000000, MSBFIRST, SPI_MODE0);
// … wait for ADC ready variables …
unsigned long start_time, used_time, delta_t, ADCdelay;
unsigned long s_time, e_time, laps;
boolean readADC , setADC, ADCready, set_read;
uint8_t stat, val1, val2, val3, result; // uint8_t = unsigned int 8 bit = byte;
unsigned long temp0; // 24 bit ADC value
unsigned int Temperatur[3]; // Hex Temperatur value of each channel
unsigned int CelsiusT;
float Celsius[3]; // scaled or mapped Celsius Degree
int ADC_run; // circle through ADC 0 - 3
// +++++++++++++++++ Set up +++++++++++++
void setup() {
Serial.begin(9600); // for debugging and communication
SPI.begin();
// read three bytes from device A
SPI.beginTransaction(settingsA);
// BEGIN( col,row) for LCD
lcd.begin(16, 4);
lcd.clear();
lcd.setCursor(0, 0); // colum 0 , row 0 = 1st and line
Serial.println();
Serial.print(" MOSI:");
Serial.print(PIN_SPI_MOSI); // to verify the correct pin selction for the selected hardware
Serial.print(" SCK:");
Serial.print(PIN_SPI_SCK);
Serial.print(" MISO:");
Serial.print(PIN_SPI_MISO);
Serial.print(" SS:");
Serial.println(PIN_SPI_SS);
lcd.write(" Magnet Heating “);
lcd.setCursor(0,1); // begin 2nd line
lcd.write(” Unit “);
lcd.setCursor(0,3); // begin of line 4
lcd.write(” Version 1.0 ");
delay(1000); // enable the user to see header and version
setADC=false; // enter channel select routine
readADC=false; //read selected channel
set_read=false; // toggle function ; if false set ADC true & readADC false
ADCdelay = 160; // equals to 160 ms waiting time for ADC conversion
ADC_run=0; // select channel 0 - 3
start_time=millis(); // set time to actual now
}
// +++++++++++ end setup +++++++++++++++++
void loop() {
used_time=millis(); // get actual time counter
if (used_time < start_time) start_time= millis(); // reset time after timer overrun
delta_t = used_time - start_time; // calculate actual time passed
if (delta_t > ADCdelay) // ADC ready for readout or channel select
{
Serial.println(ADC_run); // if this line is removed channel 3 can not be selected!!!
if (!set_read)
{
setADC=true; // enable channel select
readADC=false; // disable reading ADC
set_read=true; // toggle function select
}
else
{
setADC=false; // disable channel select
readADC=true; // enable reading ADC
set_read=false; // toggle function select
}
// } // end if
// ************ read ADC ***********
if (readADC) // if enabled start reading ADC
{
digitalWrite (PIN_SPI_SS, LOW); // chip select for ADC
// reading only, so data sent does not matter
val1 = SPI.transfer(0);
val2 = SPI.transfer(0);
val3 = SPI.transfer(0);
digitalWrite (PIN_SPI_SS, HIGH); // chip deselect
// create a 20 bit word out of 3 bytes ADC readings
temp0=0;
temp0= (temp0 | val1) << 8; // transfere a byte and shift left
temp0= (temp0 | val2) << 8; // tranfere 2nd byte and shift left
temp0 = (temp0 | val3) >> 4; // transfere 3rd byte and shift 4 unused bits right
// as the last 4 bits are not used in this version
Temperatur[ADC_run] = temp0 & 0xFFFF; // convert to integer and cut off status bits
CelsiusT = map(Temperatur[ADC_run],0x83,0xFFFF,0,50000); // 4 - 20mA scaling 0ºC - 50ºC
Celsius[ADC_run] = CelsiusT/1000.0; // the use of decimal point makse constand a float
// ======== display channel no, nominal value and actual value on 4x16 LCD
if (ADC_run == 0) {
lcd.setCursor(0,ADC_run); // set cursor in line 0 … 3
lcd.print(txt1);
lcd.print(ADC_run);
lcd.print(set0);
lcd.print(Celsius[ADC_run],3);
}
if (ADC_run == 1) {
lcd.setCursor(0,ADC_run); // set cursor in line 0 … 3
lcd.print(txt1);
lcd.print(ADC_run);
lcd.print(set1);
lcd.print(Celsius[ADC_run],3);
}
if (ADC_run == 2) {
lcd.setCursor(0,ADC_run); // set cursor in line 0 … 3
lcd.print(txt1);
lcd.print(ADC_run);
lcd.print(set2);
lcd.print(Celsius[ADC_run],3);
}
if (ADC_run == 3) {
lcd.setCursor(0,ADC_run); // set cursor in line 0 … 3
lcd.print(txt1);
lcd.print(ADC_run);
lcd.print(set3);
lcd.print(Celsius[ADC_run],3);
}
++ADC_run;
if (ADC_run >=4) ADC_run=0;
start_time = millis(); // restart ADC waiting time
} // end if {readADC}
if (setADC)
{
//send channel select to device
digitalWrite(PIN_SPI_SS, LOW); // not set by SPI lib ! chip select
SPI.transfer(SelChannel[ADC_run]);
digitalWrite (PIN_SPI_SS, HIGH); // chip deselct
start_time = millis(); // restart ADC waiting time
} // end if setADC
} // end if delta_t>
//} // end loop
}
