MeshCoreTel-firmware/variants/heltec_v3/HeltecV3Board.h

#pragma once

#include <Arduino.h>
#include <helpers/RefCountedDigitalPin.h>
#include <helpers/ESP32Board.h>

// built-ins
#ifndef PIN_VBAT_READ              // set in platformio.ini for boards like Heltec Wireless Paper (20)
  #define  PIN_VBAT_READ    1
#endif
#ifndef PIN_ADC_CTRL              // set in platformio.ini for Heltec Wireless Tracker (2)
  #define  PIN_ADC_CTRL    37
#endif
#ifndef ADC_MULTIPLIER            //default ADC multiplier
  #define ADC_MULTIPLIER 5.42
#endif
#define  PIN_ADC_CTRL_ACTIVE    LOW
#define  PIN_ADC_CTRL_INACTIVE  HIGH

#include <driver/rtc_io.h>

class HeltecV3Board : public ESP32Board {
private:
  bool adc_active_state;
  bool battery_reporting_enabled;

public:
  RefCountedDigitalPin periph_power;

  HeltecV3Board() : adc_active_state(false),
                    battery_reporting_enabled(true),
                    periph_power(PIN_VEXT_EN) { }

  void begin() {
    ESP32Board::begin();

    // Auto-detect correct ADC_CTRL pin polarity (different for boards >3.2)
    pinMode(PIN_ADC_CTRL, INPUT);
    adc_active_state = !digitalRead(PIN_ADC_CTRL);

    pinMode(PIN_ADC_CTRL, OUTPUT);
    digitalWrite(PIN_ADC_CTRL, !adc_active_state); // Initially inactive

    periph_power.begin();

    esp_reset_reason_t reason = esp_reset_reason();
    if (reason == ESP_RST_DEEPSLEEP) {
      long wakeup_source = esp_sleep_get_ext1_wakeup_status();
      if (wakeup_source & (1 << P_LORA_DIO_1)) {  // received a LoRa packet (while in deep sleep)
        startup_reason = BD_STARTUP_RX_PACKET;
      }

      rtc_gpio_hold_dis((gpio_num_t)P_LORA_NSS);
      rtc_gpio_deinit((gpio_num_t)P_LORA_DIO_1);
    }
  }

  void enterDeepSleep(uint32_t secs, int pin_wake_btn = -1) {
    esp_sleep_pd_config(ESP_PD_DOMAIN_RTC_PERIPH, ESP_PD_OPTION_ON);

    // Make sure the DIO1 and NSS GPIOs are hold on required levels during deep sleep
    rtc_gpio_set_direction((gpio_num_t)P_LORA_DIO_1, RTC_GPIO_MODE_INPUT_ONLY);
    rtc_gpio_pulldown_en((gpio_num_t)P_LORA_DIO_1);

    rtc_gpio_hold_en((gpio_num_t)P_LORA_NSS);

    if (pin_wake_btn < 0) {
      esp_sleep_enable_ext1_wakeup( (1L << P_LORA_DIO_1), ESP_EXT1_WAKEUP_ANY_HIGH);  // wake up on: recv LoRa packet
    } else {
      esp_sleep_enable_ext1_wakeup( (1L << P_LORA_DIO_1) | (1L << pin_wake_btn), ESP_EXT1_WAKEUP_ANY_HIGH);  // wake up on: recv LoRa packet OR wake btn
    }

    if (secs > 0) {
      esp_sleep_enable_timer_wakeup(secs * 1000000);
    }

    // Finally set ESP32 into sleep
    esp_deep_sleep_start();   // CPU halts here and never returns!
  }

  void powerOff() override {
    enterDeepSleep(0);
  }

  uint16_t getBattMilliVolts() override {
    if (!battery_reporting_enabled) {
      return 0;
    }

    analogReadResolution(10);
    digitalWrite(PIN_ADC_CTRL, adc_active_state);

    uint32_t raw = 0;
    for (int i = 0; i < 8; i++) {
      raw += analogRead(PIN_VBAT_READ);
    }
    raw = raw / 8;

    digitalWrite(PIN_ADC_CTRL, !adc_active_state);

    uint16_t mv = (ADC_MULTIPLIER * (3.3 / 1024.0) * raw) * 1000;

    // Heltec V3 USB-powered boards without a battery can bias or float the
    // VBAT sense rail, which shows up as an impossible LiPo voltage.
    if (mv > 4400) {
      return 0;
    }

    return mv;
  }

  bool supportsBatteryReporting() const override {
    return true;
  }

  bool setBatteryReporting(bool enabled) override {
    battery_reporting_enabled = enabled;
    return true;
  }

  bool isBatteryReportingEnabled() const override {
    return battery_reporting_enabled;
  }

  const char* getManufacturerName() const override {
    return "Heltec V3";
  }
};