MCP23017 examples

Reading

#include <chrono>
#include <cstdint>
#include <iostream>
#include <thread>

#include "i2c_bus/i2c.hh"
#include "mcp23017/mcp23017.hh"

int main([[maybe_unused]] int argc, [[maybe_unused]] char* argv[]) {
    iplo::I2C i2c("/dev/i2c-1");
    iplo::MCP23017 mcp(i2c, 0x20);
    if (!mcp.begin()) {
        std::cout << "Error initializing communication with GPIO expander\n";
        return -1;
    }

    for (int pin = 0; pin < iplo::MCP23017::PINS; ++pin) {
        mcp.pinMode(pin, iplo::PinMode::INPUT);
        mcp.setPullUp(pin, true);
        mcp.setPolarity(pin, true);  // reversed polarity because of pull up
    }

    for (int i = 0; i < 10; ++i) {
        const auto value = mcp.digitalRead16();
        for (std::uint8_t pin = 0; pin < iplo::MCP23017::PINS; ++pin) {
            const auto pinValue = iplo::MCP23017::extractPinValue(value, pin);
            std::cout << "Value for pin " << +pin << ": " << +pinValue << "\n";
        }

        std::cout << "==================\n\n";
        std::this_thread::sleep_for(std::chrono::seconds(1));
    }

    return 0;
}

Writing

#include <chrono>
#include <thread>

#include "i2c_bus/i2c.hh"
#include "mcp23017/mcp23017.hh"

int main([[maybe_unused]] int argc, [[maybe_unused]] char* argv[]) {
    iplo::I2C i2c("/dev/i2c-1");
    iplo::MCP23017 mcp(i2c, 0x20);
    if (!mcp.begin()) {
        return -1;
    }

    for (int pin = 0; pin < iplo::MCP23017::PINS; ++pin) {
        mcp.pinMode(pin, iplo::PinMode::OUTPUT);
        std::this_thread::sleep_for(std::chrono::milliseconds(200));
    }

    for (int pin = 0; pin < iplo::MCP23017::PINS; ++pin) {
        mcp.digitalWrite(pin, 1 - pin % 2);
        std::this_thread::sleep_for(std::chrono::milliseconds(200));
    }

    return 0;
}