Code Examples

Read Variable Voltage from a Potentiometer

Following code configures GPIO 27 to be used in conjunction with the ADC to read a variable voltage. This variable voltage is produced by a Potentiometer.

#include <stdio.h>
#include <pico/stdlib.h>
#include <hardware/gpio.h>
#include <hardware/adc.h>

#define PIN 27
#define ADC_NUM 1

void setup()
{
    stdio_init_all();
    adc_init();                         // Initialize the ADC
    adc_gpio_init(PIN);                 // Initialize a GPIO
    adc_select_input(ADC_NUM);          // Select appropriate ADC Input for measurement
}

void loop()
{
    uint16_t x = adc_read();            // Read voltage on selected ADC Input
    printf("%fV\r\n",x/4095.0*3.3);     // Convert the unsigned integer into a voltage and print it
    sleep_ms(100);
}

int main()
{
    setup();
    while (true)
        loop();
}

Onboard Temperature Sensor

Use ADC to measure temperature from the onborad temperature sensor.

#include <stdio.h>
#include <pico/stdlib.h>
#include <hardware/gpio.h>
#include <hardware/adc.h>

#define adcPin 4

void setup()
{
    stdio_init_all();

    adc_init();
    adc_set_temp_sensor_enabled(true);
    adc_select_input(adcPin);

}

void loop()
{
    int x = adc_read();
    float adcConvertToVoltage  = (float) x/4095*3.3;
    float convertToTemp = 27-(adcConvertToVoltage-0.706)/0.001721;
    printf("%.2f degrees C\r\n", convertToTemp);
    sleep_ms(100);
}

int main()
{
    setup();

    while (true)
        loop();
}

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