ADC on the Odroid

One of the biggest features that the ODROID-C1 (odroid, from now on) has that is different than the Raspberry Pi B+ is the ADC. This is a welcome addition and will allow you to interface with analog sensors in a very simple way.

I figured I would use a photocell since I just finished doing a photocell blog project for the B+, so everything was in place.

The first thing I did was log into my odroid, and from my home directory type the following commands:

git clone https://github.com/hardkernel/wiringPi
cd wiringPi/
./build

This built and installed the wiringPi library on my odroid.

Next I opened my favorite code editor (not really, but I installed a pretty cool ide from the Lubuntu Software Store, CodeLite) and entered the following code:

#include <stdio.h>
#include <time.h>

#include <wiringPi.h>

#define PORT_ADC1   0 


int main (int argc, char *argv[])
{
    static int timer = 0 ;
  int adcValue;

    wiringPiSetup();

    for(;;)    {

        if (millis () < timer)  continue ;

        timer = millis() + 100;

        adcValue = analogRead(PORT_ADC1);

       printf("Value read is %d\n", adcValue);
    }

    return 0 ;
}

I attached the code below.

time to hook up the circuit:

I connected pin 1 of the Odroid to the + power rail on my breadboard

Pin 6 to the - Power rail

straddled a 1K resistor (any value will work) from the - rail to row 10

straddled a photocell over the channel in the middl on row 10

connected a jumper from the power rail to row 10 on the right side of the channel

connected a jumper from pin 40 of the odroid to row 10 of the bread board right between the photocell and the resistor

see the image below:

then I typed:

gcc -o photoSensor photoSensor.c -lwiringPi -lpthread

and finally:

sudo ./photoSensor

this gave me an ouput as follows:

That was with me waving my hand all above the sensor.

This is what the finished product looked like:

This wasn't intended to be a sophisticated project of any kind, just a quick example of how to use the ADC and the wiringPi libraries on the ODROID-C1.