Interfacing ESP8266-03 with ADS8343 via SPI bus
Posted: Sun Mar 27, 2016 12:13 pmI need some help to interface an ADS8343 16-bit ADC with and ESP8266-03 using SPI.
I have managed to read the ADC using an arduino Uno but I was not successful with the ESP.
Here is the code I am try to use. I have used a library for the ADS8343 from digilent analog shield.
The serial output is full of random numbers that does not make sense. I think that the communication is not being done correctly. Unfortunately I do not have a logic analyzer to check the SPI lines. Is there someone that can help me on this?
I have managed to read the ADC using an arduino Uno but I was not successful with the ESP.
Here is the code I am try to use. I have used a library for the ADS8343 from digilent analog shield.
Code: Select all
#include <SPI.h>
#define CS_PIN 15
#define BUSY_PIN 2
#define multiplier 0.050140380859375
unsigned int count = 0;
void setChannelAndModeByte(byte channel, bool mode){
//control byte
//S - sentinel, always 1
//A2 - channel select
//A1 - channel select
//A0 - channel select
//- N/C
//Single / Diff pair
//PD1 - power down mode
//PD0 - power down mode
byte control = B10000010; //default to channel 1 '001'
//channel mask
if(channel == 3){
control = control | B11100000;
}
else if(channel == 2){
control = control | B10100000;
}
else if(channel == 1){
control = control | B11010000;
}
else if(channel == 0){
control = control | B00010000;
}
//differential mode active
if(mode){
control = control & B11111011;
}
else{
control = control | B00000100;
}
SPI.transfer(control);
return;
}
unsigned int readADC(int channel, bool mode) {
// initialize SPI:
SPI.setDataMode(SPI_MODE3);
digitalWrite(CS_PIN,LOW);
setChannelAndModeByte(channel, mode);
digitalWrite(CS_PIN,HIGH);
//wait for busy signal to rise. If it lasts a while, try resending.
while(digitalRead(BUSY_PIN) == 0); //wait for pin 2 to == 0
digitalWrite(CS_PIN,LOW);
//collect data
byte high = SPI.transfer(0x00);
byte low = SPI.transfer(0x00);
//release chip select
digitalWrite(CS_PIN,HIGH);
//compile the result into a 32 bit integer.
int result;
result = (int)high<<24;
result+= low<<16;
//make into an unsigned int for compatibility with the DAC used on the analog shield.
if(result < 0)
{
result = result >> 16;
result &= 0x7FFF;
}
else
{
result = result >> 16;
result |= 0x8000;
}
return result;
}
void setup()
{
Serial.begin(115200); // For debugging output
Serial.println("Program Starting...");
pinMode(CS_PIN, OUTPUT);
pinMode(BUSY_PIN, INPUT);
pinMode(14, OUTPUT);
pinMode(12, INPUT);
pinMode(13, OUTPUT);
SPI.begin();
SPI.setFrequency(1000000L);
}
void loop()
{
count = readADC(0, false); //read in on port labeled 'IN0'
Serial.print("Channel 0 = ");
Serial.println(count);
delay(500);
count = readADC(1, false); //read in on port labeled 'IN0'
Serial.print("Channel 1 = ");
Serial.println(count);
delay(500);
count = readADC(2, false); //read in on port labeled 'IN0'
Serial.print("Channel 2 = ");
Serial.println(count);
delay(500);
count = readADC(3, false); //read in on port labeled 'IN0'
Serial.print("Channel 3 = ");
Serial.println(count);
Serial.println();
delay(1000);
}The serial output is full of random numbers that does not make sense. I think that the communication is not being done correctly. Unfortunately I do not have a logic analyzer to check the SPI lines. Is there someone that can help me on this?