weather app

weather.c

#include <k8mod_app.h>
#include <bitmaps.h>

#define FRAME_DURATION 500
#define FRAME_COUNT 2

const uint8_t DEGREE[] = {0x8e}; // Offset 28

const uint8_t RAIN[FRAME_COUNT][5] = {ICON_WEATHER_RAIN_0_V1, ICON_WEATHER_RAIN_1_V1};
const uint8_t CLOUDY[FRAME_COUNT][5] = {ICON_WEATHER_CLOUDY_0_V3, ICON_WEATHER_CLOUDY_1_V3};
const uint8_t SUNNY[FRAME_COUNT][5] = {ICON_WEATHER_SUNNY_0_V2, ICON_WEATHER_SUNNY_1_V2};
const uint8_t SUNNY_N_CLOUDY[FRAME_COUNT][5] = {ICON_WEATHER_SUNNY_N_CLOUDY_0_V3, ICON_WEATHER_SUNNY_N_CLOUDY_1_V3};
const uint8_t WINDY[FRAME_COUNT][5] = {ICON_WEATHER_WINDY_0_V1, ICON_WEATHER_WINDY_1_V1};
const uint8_t NONE[FRAME_COUNT][5] = {{0xF8, 0x23, 0x1A, 0xA8, 0x1F}, {0xF8, 0x00, 0x00, 0x00, 0x1F}};

const Format FMT_TITLE = {
    .seg = Seg_S9,
    .offset = 0,
    .width = 7,
    .fill_with = ' ',
    .align = Alignment_Left,
};

const Format FMT_TEMP = {
    .seg = Seg_S7,
    .offset = 0,
    .width = 3,
    .fill_with = ' ',
    .align = Alignment_Right,
};

static bool m_invalidated;
static int8_t m_temp;
static uint8_t *m_icon;
static uint16_t m_current_frame;
const char *init() {
  m_invalidated = true;
  m_temp = 0;
  m_icon = (uint8_t *)NONE;
  m_current_frame = 0;
  return "CWeather";
}

uint16_t get_script_uuid() {
  return 0x43A7;
}

void tick(const uint64_t *big_time) {
  uint32_t time = (uint32_t)*big_time; // FIXME: can't do math operations on uint64_t. Otherwise: __aeabi_uldivmod undefined
  uint16_t current = time % (FRAME_DURATION * FRAME_COUNT);
  uint16_t frame_idx = current / FRAME_DURATION;

  if (frame_idx != m_current_frame) {
    m_current_frame = frame_idx;
    m_invalidated = true;
  }

  if (m_invalidated) {
    m_invalidated = false;
    screen_clear();
    screen_write_string_to_seg("WEATHER", &FMT_TITLE);
    if (m_icon != (uint8_t *)NONE) {
      screen_write_number_to_seg(m_temp, &FMT_TEMP);
      screen_write_bytes_to_seg(Seg_S7, DEGREE, sizeof(DEGREE), 8, 21);
    }
    screen_write_to_matrix((const uint8_t(*)[5])(m_icon + m_current_frame * 5));
  }
}

void on_bluetooth_receive(const uint8_t *data, uint32_t len) {
  if (len != 2) {
    print("Unexpected data. Probably a HTTP error");
  } else {
    print("Got data from phone");
    m_temp = (int8_t)data[1];
    m_invalidated = true;
    int8_t wmo = (int8_t)data[0];
    if (wmo <= 1) {
      m_icon = (uint8_t *)SUNNY;
    } else if (wmo <= 2) {
      m_icon = (uint8_t *)SUNNY_N_CLOUDY;
    } else if (wmo <= 3) {
      m_icon = (uint8_t *)CLOUDY;
    } else if (wmo < 95) {
      m_icon = (uint8_t *)RAIN;
    } else {
      m_icon = (uint8_t *)WINDY;
    }
  }
}

void on_connection_changed(ConnectionStatus status) {
  if (status == ConnectionStatus_ValidConnection) {
    bluetooth_send(NULL, 0);
  }
}

void invalidate() {
  m_invalidated = true;
}

weather.js

const app = {
  uuid: 0x43A7,
  on_data: (array) => {
    const url = 'https://api.open-meteo.com/v1/forecast?latitude=25.04&longitude=121.52&current_weather=true';
    fetch(url, data => {
      const json = JSON.parse(data);
      const resp = new Int8Array(2);
      const wwo = json.current_weather.weathercode;
      const temp = json.current_weather.temperature;
      resp[0] = wwo;
      resp[1] = temp;
      send_bytes(resp);
    }, error => { send_bytes(new Int8Array(0));});
  }
};
app