雪寄せ時間を記録するためのM5StickCのプログラム

env.h

#ifndef __ENV_H__
#define __ENV_H__

#define WIFI_SSID           "your wifi ssid"
#define WIFI_PASSWORD       "your password for WIFI_SSID"
//#define WIFI_SSID_2         "your second wifi ssid if you have"
//#define WIFI_PASSWORD_2     "your password for WIFI_SSID2"
//#define WIFI_SSID_3         "your third wifi ssid if you have"
//#define WIFI_PASSWORD_3     "your password for WIFI_SSID3"

#define AMBIENT_CHANNEL_ID    1234    // your ambient channel id
#define AMBIENT_WRITE_KEY     "your write key of ambient"

#endif

main.c

#include <Arduino.h>
#include <M5Unified.h>
#include <WiFiMulti.h>
#include <Ambient.h>
#include "env.h"

static float velocity[2] = {0};
static float diff[2] = {0};
static float diff2[2] = {0};
static int num_of_steps = 0;


static void imu_task(void*)
{
  float threshold = 0.004; // 0.008; // 0.010; //0.005;
  int b_ptr = 0;
  float val[3];
  float vel = 0;
  float sum = 0;
  bool over = false;
  int tap_size = 63;
  float z_buf[tap_size] = {0};
  int ignore_count = 0;

  while(true) {
    M5.Imu.getAccel(&val[0], &val[1], &val[2]);
    vel = sqrt(val[0] * val[0] + val[1] * val[1] + val[2] * val[2]);

    sum -= z_buf[b_ptr];
    z_buf[b_ptr] = vel;
    sum += z_buf[b_ptr];
    b_ptr = (b_ptr + 1) % tap_size;
    
    velocity[0] = sum / tap_size;
    diff[0] = velocity[0] - velocity[1];
    diff2[0] = diff[0] - diff[1];

    velocity[1] = velocity[0];
    diff[1] = diff[0];
    diff2[1] = diff2[0];
    
    // 250ms以内は無視
    if (ignore_count >= 25) {
      if (diff2[0] <= - threshold || diff2[0] >= threshold) {
        if (over == false) {
          over = true;
          ignore_count = 0;
          num_of_steps++;
        }
      } else {
          over = false;
      }
    }
    delay(10);
    ignore_count++;
  }
}

static void transfer_task(void*)
{
  Ambient ambient;
  unsigned long sent_at = millis();
  WiFiMulti wifiMulti;
  WiFiClient client;
  int power_off_count = 0;
  int power_off_min = 10;

  WiFi.disconnect();
  WiFi.softAPdisconnect(true);
  WiFi.mode(WIFI_STA);
  wifiMulti.addAP(WIFI_SSID, WIFI_PASSWORD);
#ifdef WIFI_SSID2
  wifiMulti.addAP(WIFI_SSID2, WIFI_PASSWORD2);
#endif
#ifdef WIFI_SSID3
  wifiMulti.addAP(WIFI_SSID3, WIFI_PASSWORD3);
#endif

  ambient.begin(AMBIENT_CHANNEL_ID, AMBIENT_WRITE_KEY, &client);

  while(true) {
    if (wifiMulti.run() == WL_CONNECTED) {
      unsigned long now = millis();
      if (now - sent_at >= 60000) {
        if (num_of_steps < 15) {
          if (++power_off_count >= power_off_min) {
            M5.Power.powerOff();
          }
        } else {
          power_off_count = 0;
        }

        ambient.set(1, num_of_steps);
        ambient.send();
        num_of_steps = 0;
        sent_at = now;
      }
    }
  }
}

static void display_bar(int no, float fvalue, float gain, int min, int max) {
  int value = fvalue * gain;
  int space = 2;
  int bar_height = 20;
  int h = M5.Lcd.height();
  int w = M5.Lcd.width();
  int y = h - (space + bar_height) * (no + 1) + space;

  int bar_value = map(value, min, max, 0, w);
  Serial.println(bar_value);
  bar_value = constrain(bar_value, 0, w);
  Serial.println(bar_value);

  M5.Lcd.fillRect(0, y, w, bar_height, TFT_BLACK);
  if (min >= 0) {
    // 正方向のみ
    M5.Lcd.fillRect(0, y, bar_value, bar_height, TFT_GREEN);
    M5.Lcd.fillRect(0, y, 3, bar_height, TFT_WHITE);
  } else {
    // 正負センター振り分け
    int half_w = w / 2;
    if (bar_value < half_w) {
      // 負
      M5.Lcd.fillRect(bar_value, y, half_w - bar_value, bar_height, TFT_RED);
    } else {
      // 正
      M5.Lcd.fillRect(half_w, y, bar_value - half_w, bar_height, TFT_GREEN);
    }
    M5.Lcd.fillRect(half_w - 1, y, 2, bar_height, TFT_WHITE);
  }
  M5.Lcd.setCursor(1, y + 3);
  M5.Lcd.printf("%8.4f", fvalue);
}

static void display() {
  display_bar(0, velocity[0], 10000, 0, 20000);
  display_bar(1, diff[0], 10000, -200, 200);
  display_bar(2, diff2[0], 10000, -200, 200);

  int x = M5.Lcd.width() * 3 / 4;
  M5.Lcd.setCursor(x, 1);
  M5.Lcd.printf("%6d", num_of_steps);
}

void setup() {
  auto cfg = M5.config();

  cfg.clear_display = true;  // default=true. clear the screen when begin.
  cfg.output_power  = false;  // default=true. use external port 5V output.
  cfg.internal_imu  = true;  // default=true. use internal IMU.
  cfg.internal_rtc  = false;  // default=true. use internal RTC.
  cfg.internal_spk  = false;  // default=true. use internal speaker.
  cfg.internal_mic  = false;  // default=true. use internal microphone.
  cfg.external_imu  = false;  // default=false. use Unit Accel & Gyro.
  cfg.external_rtc  = false;  // default=false. use Unit RTC.
  cfg.external_spk  = false; // default=false. use SPK_HAT / ATOMIC_SPK
  cfg.led_brightness = 50;   // default= 0. system LED brightness (0=off / 255=max) (※ not NeoPixel)

  M5.begin(cfg);

  // Rotate LCD origin
  M5.Lcd.setRotation(1);
  M5.Lcd.setTextSize(1);

  // LED OFF
  pinMode(GPIO_NUM_10, OUTPUT);
  digitalWrite(GPIO_NUM_10, HIGH);

  // IMU task
  xTaskCreatePinnedToCore(imu_task, "imu_task", 2048, NULL, 25, NULL, APP_CPU_NUM);
  xTaskCreatePinnedToCore(transfer_task, "transfer_task", 4096, NULL, 25, NULL, APP_CPU_NUM);
}

void loop() {
  Serial.print(".");
  display();
  delay(100);
}

platformio.ini

[env:m5stick-c]
platform = espressif32
board = m5stick-c
framework = arduino
lib_deps = 
	m5stack/M5Unified@^0.0.7
	ambientdatainc/Ambient ESP32 ESP8266 lib@^1.0.3
monitor_speed = 115200