Hi tried to set up a code for auto sequenceing through 8 channels (sensors) and concerting the anaolg to digital signal (reding out with Arduino Mega). Apparently the data does not make sense. I checked with the oscilloscope that the transmission and receiving works properly. Hence, I assume it is due to the code. Could you please help me? The sample code did not help me in this regard.
#include <SPI.h>
// chip select
uint8_t csPins[] = {53}; //ADC csPins to Arduino, specify the Arduino pins
// Mode Clock Polarity (CPOL) Clock Phase (CPHA) Output Edge Data Capture
// SPI_MODE0 0 0 Falling Rising
// SPI_MODE1 0 1 Rising Falling
// SPI_MODE2 1 0 Rising Falling
// SPI_MODE3 1 1 Falling Rising
static const SPISettings SPI_SETTINGS {1000000, MSBFIRST, SPI_MODE0};
// Register addresses
static const uint8_t ADDR_SYSTEM_STATUS {0x00};
static const uint8_t ADDR_GENERAL_CFG {0x01};
static const uint8_t ADDR_DATA_CFG {0x02};
static const uint8_t ADDR_OSR_CFG {0x03};
static const uint8_t ADDR_PIN_CFG {0x05};
static const uint8_t ADDR_SEQUENCE_CFG {0x10};
static const uint8_t ADDR_CHANNEL_SEL {0x11};
static const uint8_t ADDR_AUTO_SEQ_CH_SEL {0x12};
static const uint8_t OPCODE_NO_OP {0x00};
static const uint8_t OPCODE_WR_REG {0x08};
static const uint8_t OPCODE_RD_REG {0x10};
static const uint8_t OPCODE_SET_BIT {0x18};
static const uint8_t OPCODE_CLR_BIT {0x20};
int8_t selected_adc_idx {-1};
void selectADC(uint8_t idx = 0) {
digitalWrite(csPins[idx], LOW);
selected_adc_idx = idx;
}
void deselectADC() {
digitalWrite(csPins[selected_adc_idx], HIGH);
selected_adc_idx = -1;
}
uint8_t readRegister(uint8_t adc_idx, uint8_t reg)
{
// send 24-bit cmd: RD_REG, addr, NO_OP
uint8_t cmd[3] {OPCODE_RD_REG, reg, OPCODE_NO_OP};
uint8_t response[3];
selectADC(adc_idx);
SPI.beginTransaction(SPI_SETTINGS);
for (int i = 0; i < 3; i++)
{
SPI.transfer(cmd[i]);
}
// CS needs to be pulled high for the command to be processed
deselectADC();
delayMicroseconds(100);
selectADC(adc_idx);
for (int i = 0; i < 3; i++)
{
response[i] = SPI.transfer(0);
}
SPI.endTransaction();
deselectADC();
return response[0];
}
void writeRegister(uint8_t adc_idx, uint8_t addr, uint8_t val)
{
// send 24-bit cmd: WR_REG, addr, data
uint8_t cmd[3] {OPCODE_WR_REG, addr, val};
selectADC(adc_idx);
SPI.beginTransaction(SPI_SETTINGS);
for (int i = 0; i < 3; i++)
{
SPI.transfer(cmd[i]);
}
SPI.endTransaction();
deselectADC();
}
void calibrateADC(uint8_t adc_idx)
{
bool calibrated = false;
// Set calibration bit
uint8_t cfg = readRegister(adc_idx, ADDR_GENERAL_CFG);
cfg |= 0x02;
writeRegister(adc_idx, ADDR_GENERAL_CFG, cfg);
// Wait for calibration bit to go back to 0
while (!calibrated)
{
delayMicroseconds(100);
cfg = readRegister(adc_idx, ADDR_GENERAL_CFG);
//Serial.print(cfg);
if ((cfg && 0x02) == 0)
{
calibrated = true;
}
}
Serial.print("finished calibration");
}
void initADC(uint8_t adc_idx)
{
// Add channel ID to ADC data
uint8_t data_cfg = readRegister(adc_idx, ADDR_DATA_CFG);
data_cfg |= 0x10;
writeRegister(adc_idx, ADDR_GENERAL_CFG, data_cfg);
// Enable all channels to be in sequence
writeRegister(adc_idx, ADDR_AUTO_SEQ_CH_SEL, 0xFF);
// Select auto sequence mode
uint8_t seq_cfg = readRegister(adc_idx, ADDR_SEQUENCE_CFG);
seq_cfg |= 0x11;
writeRegister(adc_idx, ADDR_GENERAL_CFG, seq_cfg);
}
void readADC(uint8_t adc_idx, float* outputData)
{
uint8_t data[2];
uint8_t channel;
uint16_t adcValue;
selectADC(adc_idx);
SPI.beginTransaction(SPI_SETTINGS);
for (int i = 0; i < 2; i++)
{
data[i] = SPI.transfer(0);
//Serial.println(data[i]);
}
SPI.endTransaction();
deselectADC();
channel = data[1] & 0x0F;
adcValue = ((((uint16_t) data[0]) << 4) & 0x0FF0) | ((((uint16_t) data[1]) >> 4) & 0x000F);
Serial.println(adcValue);
// Scaling: AVDD / 4096
*(outputData + channel) = ((float) adcValue) * (5.0f/4096.0f);
}
void setup()
{
// Setup CS pins
for (int i = 0; i < sizeof(csPins); i++)
{
pinMode(csPins[i], OUTPUT);
digitalWrite(csPins[i], HIGH);
}
// Setup SPI
SPI.begin();
// Setup Serial
Serial.begin(115200);
// Setup ADC
for (int i = 0; i < sizeof(csPins); i++)
{
calibrateADC(0);
initADC(0);
}
delay(1);
}
void loop()
{
float adcValues[8];
char buffer[50];
for (int i = 0; i < 8; i++)
{
Serial.print("channel "); Serial.println(i);
readADC(0, adcValues);
delayMicroseconds(10);
}
// sprintf(buffer, "ADC Values: \t CH0: %.2f \t CH1: %.2f \t CH2: %.2f \t CH3: %.2f \t CH4: %.2f \t CH5: %.2f \t CH6: %.2f \t CH7: %.2f \n\n", adcValues[0], adcValues[1], adcValues[2], adcValues[3], adcValues[4], adcValues[5], adcValues[6], adcValues[7]);
// Serial.print(buffer);
delay(1000);
}
