variant.cpp

// Enable pin remapping in this file, so pin constants are meaningful
#undef ARDUINO_CORE_BUILD

#include "Arduino.h"

#include "double_tap.h"

#include <esp_system.h>
#include <esp_ota_ops.h>
#include <esp_partition.h>

extern "C" {
void initVariant() {
  // nothing to do
}
}

// global, accessible from recovery sketch
bool _recovery_marker_found;  // double tap detected
bool _recovery_active;        // running from factory partition

#define DELAY_US 10000
#define FADESTEP 8
static void rgb_pulse_delay(void) {
  //                Bv   R^  G  x
  int widths[4] = {192, 64, 0, 0};
  int dec_led = 0;

  // initialize RGB signals from weak pinstraps
  pinMode(LED_RED, OUTPUT);
  pinMode(LED_GREEN, OUTPUT);
  pinMode(LED_BLUE, OUTPUT);
  while (dec_led < 3) {
    widths[dec_led] -= FADESTEP;
    widths[dec_led + 1] += FADESTEP;
    if (widths[dec_led] <= 0) {
      widths[dec_led] = 0;
      dec_led = dec_led + 1;
      widths[dec_led] = 255;
    }

    analogWrite(LED_RED, 255 - widths[1]);
    analogWrite(LED_GREEN, 255 - widths[2]);
    analogWrite(LED_BLUE, 255 - widths[0]);
    delayMicroseconds(DELAY_US);
  }

  // reset pins to digital HIGH before leaving
  digitalWrite(LED_RED, HIGH);
  digitalWrite(LED_GREEN, HIGH);
  digitalWrite(LED_BLUE, HIGH);
}

static void NANO_ESP32_enter_bootloader(void) {
  if (!_recovery_active) {
    // check for valid partition scheme
    const esp_partition_t *ota_part = esp_ota_get_next_update_partition(NULL);
    const esp_partition_t *fact_part = esp_partition_find_first(ESP_PARTITION_TYPE_APP, ESP_PARTITION_SUBTYPE_APP_FACTORY, NULL);
    if (ota_part && fact_part) {
      // set tokens so the recovery FW will find them
      double_tap_mark();
      // invalidate other OTA image
      esp_partition_erase_range(ota_part, 0, 4096);
      // activate factory partition
      esp_ota_set_boot_partition(fact_part);
    }
  }

  esp_restart();
}

static void boot_double_tap_logic() {
  const esp_partition_t *part = esp_ota_get_running_partition();
  _recovery_active = (part->subtype == ESP_PARTITION_SUBTYPE_APP_FACTORY);

  double_tap_init();

  _recovery_marker_found = double_tap_check_match();
  if (_recovery_marker_found && !_recovery_active) {
    // double tap detected in user application, reboot to factory
    NANO_ESP32_enter_bootloader();
  }

  // delay with mark set then proceed
  // - for normal startup, to detect first double tap
  // - in recovery mode, to ignore several short presses
  double_tap_mark();
  rgb_pulse_delay();
  double_tap_invalidate();
}

namespace {
class DoubleTap {
public:
  DoubleTap() {
    boot_double_tap_logic();
  }
};

DoubleTap dt __attribute__((init_priority(101)));
}  // namespace