M5Unit-DISTANCE/examples/UnitUnified/UnitUltraSonic/PlotToSerial/main/PlotToSerial.cpp

/*
 * SPDX-FileCopyrightText: 2024 M5Stack Technology CO LTD
 *
 * SPDX-License-Identifier: MIT
 */
/*
  Example using M5UnitUnified for UnitUltraSonic I2C/IO
*/
#include <M5Unified.h>
#include <M5UnitUnified.h>
#include <M5UnitUnifiedDISTANCE.h>
#include <M5Utility.h>
#include <M5HAL.hpp>  // For NessoN1

// *********************************************************************
// Choose connection
// *********************************************************************
#if !defined(CONNECT_VIA_I2C) && !defined(CONNECT_VIA_GPIO)
// UnitUltraSonicI2C (SKU:U098-B1)
// #define CONNECT_VIA_I2C
// UnitUltraSonicIO  (SKU:U098-B2)
// #define CONNECT_VIA_GPIO
#endif

namespace {
auto& lcd = M5.Display;
m5::unit::UnitUnified Units;
#if defined(CONNECT_VIA_I2C)
m5::unit::UnitUltraSonicI2C unit;
constexpr uint32_t interval{150};  // For I2C, the measurement interval is 150 ms or more
#elif defined(CONNECT_VIA_GPIO)
m5::unit::UnitUltraSonicIO unit;
constexpr uint32_t interval{50};  // For GPIO, the measurement interval is 50 ms or more
#else
#error "Choose connection"
#endif

}  // namespace

using namespace m5::unit::rcwl9620;

void setup()
{
    M5.begin();
    M5.setTouchButtonHeightByRatio(100);
    // The screen shall be in landscape mode
    if (lcd.height() > lcd.width()) {
        lcd.setRotation(1);
    }

    auto cfg        = unit.config();
    cfg.interval_ms = interval;
    unit.config(cfg);

#if defined(CONNECT_VIA_I2C)
    // PortA as I2C
    M5.Log.printf("Using I2C\n");
    auto pin_num_sda = M5.getPin(m5::pin_name_t::port_a_sda);
    auto pin_num_scl = M5.getPin(m5::pin_name_t::port_a_scl);

    auto board = M5.getBoard();

    // NessoN1: Arduino Wire (I2C_NUM_0) cannot be used for GROVE port.
    //   Wire is used by M5Unified In_I2C for internal devices (IOExpander etc.).
    //   Wire1 exists but is reserved for HatPort — cannot be used for GROVE.
    //   Reconfiguring Wire to GROVE pins breaks In_I2C, causing ESP_ERR_INVALID_STATE in M5.update().
    //   Solution: Use SoftwareI2C via M5HAL (bit-banging) for the GROVE port.
    // NanoC6: Wire.begin() on GROVE pins conflicts with m5::I2C_Class registered by Ex_I2C.setPort()
    //   on the same I2C_NUM_0, causing sporadic NACK errors.
    //   Solution: Use M5.Ex_I2C (m5::I2C_Class) directly instead of Arduino Wire.
    bool unit_ready{};
    if (board == m5::board_t::board_ArduinoNessoN1) {
        // NessoN1: GROVE is on port_b (GPIO 5/4), not port_a (which maps to Wire pins 8/10)
        pin_num_sda = M5.getPin(m5::pin_name_t::port_b_out);
        pin_num_scl = M5.getPin(m5::pin_name_t::port_b_in);
        M5_LOGI("getPin(M5HAL): SDA:%u SCL:%u", pin_num_sda, pin_num_scl);
        m5::hal::bus::I2CBusConfig i2c_cfg;
        i2c_cfg.pin_sda = m5::hal::gpio::getPin(pin_num_sda);
        i2c_cfg.pin_scl = m5::hal::gpio::getPin(pin_num_scl);
        auto i2c_bus    = m5::hal::bus::i2c::getBus(i2c_cfg);
        M5_LOGI("Bus:%d", i2c_bus.has_value());
        unit_ready = Units.add(unit, i2c_bus ? i2c_bus.value() : nullptr) && Units.begin();
    } else if (board == m5::board_t::board_M5NanoC6) {
        // NanoC6: Use M5.Ex_I2C (m5::I2C_Class, not Arduino Wire)
        M5_LOGI("Using M5.Ex_I2C");
        unit_ready = Units.add(unit, M5.Ex_I2C) && Units.begin();
    } else {
        M5_LOGI("getPin: SDA:%u SCL:%u", pin_num_sda, pin_num_scl);
        Wire.end();
        Wire.begin(pin_num_sda, pin_num_scl, 400 * 1000U);
        unit_ready = Units.add(unit, Wire) && Units.begin();
    }
    if (!unit_ready) {
        M5_LOGE("Failed to begin");
        lcd.fillScreen(TFT_RED);
        while (true) {
            m5::utility::delay(10000);
        }
    }
#elif defined(CONNECT_VIA_GPIO)
    // PortB as GPIO if available, PortA if not
    M5.Log.printf("Using GPIO\n");
    auto pin_num_gpio_in  = M5.getPin(m5::pin_name_t::port_b_in);
    auto pin_num_gpio_out = M5.getPin(m5::pin_name_t::port_b_out);
    if (pin_num_gpio_in < 0 || pin_num_gpio_out < 0) {
        M5_LOGW("PortB is not available");
        Wire.end();
        pin_num_gpio_in  = M5.getPin(m5::pin_name_t::port_a_pin1);
        pin_num_gpio_out = M5.getPin(m5::pin_name_t::port_a_pin2);
    }
    M5_LOGI("getPin :%d,%d", pin_num_gpio_in, pin_num_gpio_out);

    if (!Units.add(unit, pin_num_gpio_in, pin_num_gpio_out) || !Units.begin()) {
        M5_LOGE("Failed to begin");
        lcd.fillScreen(TFT_RED);
        while (true) {
            m5::utility::delay(10000);
        }
    }
#endif

    M5_LOGI("M5UnitUnified has been begun");
    M5_LOGI("%s", Units.debugInfo().c_str());

    lcd.setFont(&fonts::AsciiFont8x16);
    lcd.fillScreen(TFT_DARKGREEN);
    lcd.fillRect(8, 8, 8 * 24, 16 * 1, TFT_BLACK);
}

void loop()
{
    M5.update();

    // Periodic
    Units.update();
    if (unit.updated()) {
        M5.Log.printf("Distance:%f Raw:%x\n", unit.distance(), unit.oldest().raw_distance());

        lcd.startWrite();
        lcd.fillRect(8, 8, 8 * 24, 16 * 1, TFT_BLACK);
        lcd.setCursor(8, 8 + 16 * 0);
        lcd.printf("Distance:%7.2f mm", unit.distance());
        lcd.endWrite();
    }

    if (M5.BtnA.wasClicked()) {
        unit.stopPeriodicMeasurement();
        Data d{};
        if (unit.measureSingleshot(d)) {
            M5.Log.printf("Single: %.2f mm\n", d.distance());
        }
        unit.startPeriodicMeasurement(interval);
    }
}