Analog In

Unlike digital input pins, which only read high or low, analog pins read a range of voltages between 0 V and the chip's reference voltage (3.3 V on Endpoint). Each pin connects internally to an analog-to-digital converter (ADC) that samples the voltage and returns a digital value.

The resolution of the ADC determines the smallest voltage change that registers. A 12-bit ADC has 4096 steps, so one step is roughly 0.8 mV at a 3.3 V reference, and smaller changes are indistinguishable.

Endpoint uses the standard System.Device.Analog API through the AdcController class. Open the pin with a board-level Adc.Pin constant and read voltage or raw samples.

.NET

using GHIElectronics.Endpoint.Core;
using GHIElectronics.Endpoint.Devices.Adc;

using var adc = new AdcController();
using var input = adc.OpenPin(EPDomino24.Adc.Pin.PC3);   // mikroBUS #1 ADC

while (true) {
    Console.WriteLine($"{input.ReadVoltage().Volts:0.000} V  (raw {input.ReadRaw()})");
    Thread.Sleep(1000);
}

Python

import time
from GHIElectronics.Endpoint.Core import EPDomino24
from GHIElectronics.Endpoint.Devices.Adc import AdcController

with AdcController() as adc:
    with adc.OpenPin(EPDomino24.Adc.Pin.PC3) as input:   # mikroBUS #1 ADC
        while True:
            print(f"{input.ReadVoltage().Volts:.3f} V  (raw {input.ReadRaw()})")
            time.sleep(1)

C/C++

#include <chrono>
#include <cstdio>
#include <thread>
#include <endpoint/Adc.h>
#include <endpoint/EPDomino24.h>

using namespace GHIElectronics::Endpoint::Core;
using namespace GHIElectronics::Endpoint::Devices::Adc;

AdcController adc;
auto input = adc.OpenPin(EPDomino24::Adc::Pin::PC3);   // mikroBUS #1 ADC

while (true) {
    std::printf("%.3f V  (raw %u)\n", input.ReadVoltage().Volts(), input.ReadRaw());
    std::this_thread::sleep_for(std::chrono::milliseconds(1000));
}

ReadVoltage() returns a UnitsNet.ElectricPotential; ReadRaw() returns the integer sample straight from the ADC. The reference voltage is AdcController.VoltageReference.