#include "mbed.h"

SPI spi(p5, p6, p7); // mosi(out), miso(in), sclk(clock)
DigitalOut cs(p8); // cs (the chip select signal)

Serial pc(USBTX, USBRX); // tx, rx ( the usb serial communication )

int main() {
    // Setup the spi for 7 bit data, high steady state clock,
    // second edge capture, with a 1MHz clock rate
    spi.format(7,0);
    spi.frequency(1000000);

    // notify the user that we are starting with the ADC communication
    pc.printf("Starting ADC interaction\n");
    
    // lets just do this forever
    while (1) {

        // Select the device by seting chip select low
        cs = 0;

        // sending the 5 bits + 2 bits to ignore the null bits
        // coming from the device, so the data that is sent is 1100000
        spi.write(0xC0);
        
        // now the device sends back the readings 12 bits, 7 bits at a time
        int adc2 = spi.write(0x00);
        int adc3 = spi.write(0x00);

        // now we have to mask out the right bits
        // 31 in binary is 00011111
        int mask = 31;
        
        // we only want the 5 bits from the second reading not 7 as recived
        adc3 = mask & adc3;
        
        // we shift and or the result together
        int value = ( adc2 << 5 ) | adc3;
        
        // and voila we have the value and we can print it for the user
        pc.printf("WHOAMI register2 = %u\n", value);

        // Deselect the device
        cs = 1;

        // delay some time before reading again
        wait(1);
    }
}