Hello there!
This is my first time posting here, please forgive me if I forget stuff.
I got a problem using the ADC MCP3208 with Arduino Due.
I want to read out a flexsensor using a voltage divider and the said ADC. It is kinda working, but the value really is shaking a lot and makes it almost impossible to read out a good value.
Now I read that you can add coupling capacitators. To be honest I am quite bad at electronics and don't get (not even with the mcp datasheet) how to use it properly. Does somebody have any suggestions or maybe layouts I can use as an orientation?
I am not using a library, the code I use to read out the ADC is this:
#include <SPI.h>
#define _CS_PIN_ 52 //Pin 10 defined as the CS Pin.
void setup()
{
Serial.begin(115200); //Initalize the Serial Port to print the Analog Readings from MCP3208 onto teh Terminal.
pinMode(_CS_PIN_,OUTPUT); //Pin 10 acting as OUTPUT as CS is a OUTPUT Pin.
digitalWrite(_CS_PIN_,HIGH);
SPI.begin(); //Intialize SPI PORT
SPI.setClockDivider(52, 84);
}
void loop()
{
Serial.println(readADC(4)); //Reads Cahnnel 0 From MCP3208 and Prints the Value. Change it If u want t o read Other Cahnnel.
delay(2000); //Delay
}
uint16_t readADC(int channel)
{
uint16_t output;
byte channelBits = channel<<6;
//if(channel>3)
//Select ADC
digitalWrite(_CS_PIN_, LOW); //Select the Connected MCP3208 by pulling _CS_PIN_ LOW.
if(channel>3)
SPI.transfer(B00000111); //Defines Single mode of Operation for the ADC. D2=1 Start Bit. D1=1 Sinfgle Ended Mode D0=0 For Channel 0-3. 1 For Channel 4-7
else
SPI.transfer(B00000110);
byte msb = SPI.transfer(channelBits); //Transfers 2nd Byte from MCU to MCP3208 which returns MSB of the read data.
byte lsb = SPI.transfer(0x00);//Transfers 3rd Byte from MCU to MCP3208 which returns LSB of the read data.
digitalWrite(_CS_PIN_,HIGH); //Deselect the Connected MCP3208 by pulling _CS_PIN_ HIGH.
msb = msb & B00001111; // Make all 4 Higher bits of the MSB 0 as 12 Bit Resolution is provided by MCP3208
output = msb<<8 | lsb; //Combine MSB with LSB to form the 12 Bit Analog read Value.
return output; //Output Value
}
I didn't make it myself, I got it from here: MCP3208_Arduino/MCP3208_With_Arduino.ino at master · oksbwn/MCP3208_Arduino · GitHub
This is a part of my current layout. I am powering (VDD) the MCP with 5V from the SPI Pin header, NOT 3.3V.
Would be very happy if maybe somebody has got a few suggestions!
