Code the Weather Display
Once you've finished setting up your QT Py ESP32-S2 with CircuitPython, you can access the code and necessary libraries by downloading the Project Bundle.
To do this, click on the Download Project Bundle button in the window below. It will download as a zipped folder.
# SPDX-FileCopyrightText: 2022 Liz Clark for Adafruit Industries
# SPDX-License-Identifier: MIT
import os
import ssl
import time
import board
import wifi
import socketpool
import fontio
import neopixel
import simpleio
from adafruit_display_text.bitmap_label import Label
from adafruit_bitmap_font import bitmap_font
from displayio import Bitmap
from rainbowio import colorwheel
from adafruit_ticks import ticks_ms, ticks_add, ticks_diff
import adafruit_requests
from weather_codes import weather_codes
# minimum expected temperature
min_temp = 0
# maximum expected temperature
max_temp = 100
# first daylight hour
daytime_min = 7
# last daylight hour
daytime_max = 17
# latitude
lat = 42.36
# longitude
long = -71.06
# temp unit for API request
temperature_unit = "fahrenheit"
# temp unit for display
temp_unit = "F"
# API request to open-meteo
weather_url = "https://api.open-meteo.com/v1/forecast?"
# pass latitude and longitude
weather_url += "latitude=%d&longitude=%d&timezone=auto" % (lat, long)
# pass temperature_unit
weather_url += "¤t_weather=true&temperature_unit=%s&windspeed_unit=mph" % temperature_unit
# connect to SSID
wifi.radio.connect(os.getenv('CIRCUITPY_WIFI_SSID'), os.getenv('CIRCUITPY_WIFI_PASSWORD'))
pool = socketpool.SocketPool(wifi.radio)
requests = adafruit_requests.Session(pool, ssl.create_default_context())
def get_the_weather():
# make the API request
response = requests.get(weather_url)
# packs the response into a JSON
response_as_json = response.json()
print()
# prints the entire JSON
print(response_as_json)
print()
# gets current weather code
w = int(response_as_json['current_weather']['weathercode'])
# gets temperature
t = response_as_json['current_weather']['temperature']
temp_int = int(t)
t_c = simpleio.map_range(temp_int, min_temp, max_temp, 255, 0)
# gets time
json_time = response_as_json['current_weather']['time']
n_t = json_time.rsplit("T", 1)[-1]
n_t = int(n_t[:2])
return w, t, t_c, n_t
# initial API call
weather, temp, temp_color, new_time = get_the_weather()
# font edit code by Jeff Epler
tom_thumb = bitmap_font.load_font("tom-thumb.pcf", Bitmap)
_glyph_keys = ['bitmap', 'tile_index', 'width', 'height', 'dx', 'dy', 'shift_x', 'shift_y']
def patch_glyph(base, **kw):
d = {}
for k in _glyph_keys:
d[k] = kw.get(k, getattr(base, k))
return fontio.Glyph(**d)
class PatchedFont:
def __init__(self, base_font, patches):
self.base_font = base_font
self.patches = patches
def get_glyph(self, glyph):
g = self.base_font.get_glyph(glyph)
patch = self.patches.get(glyph)
if patch is not None:
#print("patching", repr(chr(glyph)), g)
g = patch_glyph(g, **patch)
#print("patched", g)
return g
def get_bounding_box(self):
return self.base_font.get_bounding_box()
font = PatchedFont(tom_thumb,
{
32: {'shift_x': 1, 'dx': 0},
105: {'dx': 0, 'shift_x': 2},
33: {'dx': 0, 'shift_x': 2},
})
# thank you Jeff for this PatchedFont() function!
# temperature for scrolling text
label = Label(text=" %s°%s " % (temp, temp_unit), font=font)
text = label.bitmap
# create 5x5 neopixels
pixels = neopixel.NeoPixel(board.A3, 5*5, brightness=.08, auto_write=False)
# count for pixels when drawing bitmaps
count = 0
# arrays to pack assets from weather_codes helper
# weather condition code
codes = []
# bitmaps for daytime
day_images = []
# bitmaps for nighttime
night_images = []
for i in weather_codes:
codes.append(i['code'])
day_images.append(i['day_img'])
night_images.append(i['night_img'])
# checks if it's day or night based on hour
def day_or_night(t):
if t in range(daytime_min, daytime_max):
z = day_images[weather]
else:
z = night_images[weather]
return z
# initial sprite selection
img = day_or_night(new_time)
# draw bitmap sprite
def draw_sprite(c):
for pixel in img:
pixels[c] = pixel
pixels.show()
c += 1
time.sleep(0.001)
c = 0
# ticks time tracker
clock = ticks_ms()
# 15 minutes in milliseconds
weather_check = 900000
# display current weather sprite & scroll temperature
while True:
# checks the time
if ticks_diff(ticks_ms(), clock) > weather_check:
print("pinging Open-Meteo")
# make the API request with function
# return weather ID, temp, temp color & hour
weather, temp, temp_color, new_time = get_the_weather()
# checks if it's day or night based on hour
# & returns day or night version of sprite
img = day_or_night(new_time)
label.text = " %s°%s " % (temp, temp_unit)
# reset clock
clock = ticks_add(clock, weather_check)
# draw bitmap sprite
draw_sprite(count)
# blocking delay to hold the sprite on the display
time.sleep(5)
# draw scrolling text
for v in range(2):
for i in range(text.width):
# Scoot the old text left by 1 pixel
pixels[:20] = pixels[5:]
# adjust color based on temperature
color = colorwheel(temp_color)
# Draw in the next line of text
for y in range(5):
# Select black or color depending on the bitmap pixel
pixels[20+y] = color * text[i,y]
pixels.show()
time.sleep(.1)
Upload the Code and Libraries to the QT Py ESP32-S2
After downloading the Project Bundle, plug your QT Py ESP32-S2 into the computer's USB port with a known good USB data+power cable. You should see a new flash drive appear in the computer's File Explorer or Finder (depending on your operating system) called CIRCUITPY. Unzip the folder and copy the following items to the QT Py ESP32-S2's CIRCUITPY drive.
- lib folder
- code.py
- weather_codes.py
Your QT Py ESP32-S2 CIRCUITPY drive should look like this after copying the lib folder, weather_codes.py file and the code.py file.
Add Your settings.toml File
As of CircuitPython 8.0.0, there is support for Environment Variables. These Environmental Variables are stored in a settings.toml file. Similar to secrets.py, the settings.toml file separates your sensitive information from your main code.py file. Add your settings.toml file as described in the Create Your settings.toml File page earlier in this guide. You'll need to include your CIRCUITPY_WIFI_SSID and CIRCUITPY_WIFI_PASSWORD.
CIRCUITPY_WIFI_SSID = "your-ssid-here" CIRCUITPY_WIFI_PASSWORD = "your-ssid-password-here"
The weather_codes.py File
The weather_codes.py file is a helper file that contains the sprite information and assigns the sprites to the weather condition codes that will be returned from Open-Meteo.
The file begins by defining RGB color values that will be used to create the sprites.
y = (255, 125, 0) o = (0, 0, 0) a = (0, 75, 125) w = (255, 255, 255) v = (127, 0, 255) b = (0, 0, 255) z = (0, 0, 25) g = (25, 25, 25)
The sprites are defined as five by five arrays. In total, there are eleven sprite arrays.
sun_bitmap = [
y,a,y,a,y,
a,y,y,y,a,
y,y,y,y,y,
a,y,y,y,a,
y,a,y,a,y,
]
cloud_bitmap = [
a,a,a,w,a,
a,w,w,w,a,
a,w,w,w,a,
a,a,w,w,a,
a,a,a,w,a,
]
# etc
weather_codes is a dictionary that contains the weather codes and the associated daytime and nighttime sprite. The codes are WMO Codes as defined by NOAA. There are 100 possible codes, ranging from 0 to 99. In code.py, these weather codes are used as indexes to access the appropriate sprite.
weather_codes = [
{"code" : 0, "day_img" : sun_bitmap, "night_img" : night_bitmap},
{"code" : 1, "day_img" : sun_bitmap, "night_img" : night_bitmap},
{"code" : 2, "day_img" : sun_bitmap, "night_img" : night_bitmap},
...
{"code" : 99, "day_img" : thunder_bitmap, "night_img" : nightThunder_bitmap}
]
How the CircuitPython Code Works
At the top of the code are variables that can be edited to customize your code.py file for your needs. min_temp and max_temp are used in the map_range() function that determine the color of the temperature text. The min_temp number can be negative if you are in a colder climate. daytime_min and daytime_max are used to determine the hours in which a daytime sprite is shown versus a nighttime sprite. lat and long hold your location's latitude and longitude. Finally, temperature_unit and temp_unit hold either Fahrenheit or Celsius.
# minimum expected temperature min_temp = 0 # maximum expected temperature max_temp = 100 # first daylight hour daytime_min = 7 # last daylight hour daytime_max = 17 # latitude lat = 42.36 # longitude long = -71.06 # temp unit for API request temperature_unit = "fahrenheit" # temp unit for display temp_unit = "F"
The Request URL
The API request to Open-Meteo is passed as a URL. lat, long and temperature_unit are passed to the URL string. Open-Meteo has documentation with more information on building a URL for an API request.
# API request to open-meteo weather_url = "https://api.open-meteo.com/v1/forecast?" # pass latitude and longitude weather_url += "latitude=%d&longitude=%d&timezone=auto" % (lat, long) # pass temperature_unit weather_url += "¤t_weather=true&temperature_unit=%s&windspeed_unit=mph" % temperature_unit
Get the Weather
The function get_the_weather() is used to make the API request and return values for the current weather condition, temperature, the color mapped to the current temperature and the current time.
def get_the_weather():
# make the API request
response = requests.get(weather_url)
# packs the response into a JSON
response_as_json = response.json()
print()
# prints the entire JSON
print(response_as_json)
print()
# gets current weather code
w = int(response_as_json['current_weather']['weathercode'])
# gets temperature
t = response_as_json['current_weather']['temperature']
temp_int = int(t)
t_c = simpleio.map_range(temp_int, min_temp, max_temp, 255, 0)
# gets time
json_time = response_as_json['current_weather']['time']
n_t = json_time.rsplit("T", 1)[-1]
n_t = int(n_t[:2])
return w, t, t_c, n_t
# initial API call
weather, temp, temp_color, new_time = get_the_weather()
Import the Sprites
A for statement packs the list entries from weather_codes into three different arrays: codes for the weather code numbers, day_images for the daytime sprites and night_images for the nighttime sprites.
for i in weather_codes:
codes.append(i['code'])
day_images.append(i['day_img'])
night_images.append(i['night_img'])
Day or Night?
The function day_or_night() determines which sprite is shown based on the weather condition and time of day.
# checks if it's day or night based on hour
def day_or_night(t):
if t in range(daytime_min, daytime_max):
z = day_images[weather]
else:
z = night_images[weather]
return z
# initial sprite selection
img = day_or_night(new_time)
# draw bitmap sprite
def draw_sprite(c):
for pixel in img:
pixels[c] = pixel
pixels.show()
c += 1
time.sleep(0.001)
c = 0
Tick, tick, tick...
For tracking time, the ticks library is used. ticks manages time in milliseconds, rather than seconds like in time.monotonic(). The API will be called every fifteen minutes, or every 900000 milliseconds.
# ticks time tracker clock = ticks_ms() # 15 minutes in milliseconds weather_check = 900000
The Loop
In the loop, the API is called every 15 minutes. The sprite and scrolling temperature text is updated depending on the data that is returned.
# checks the time
if ticks_diff(ticks_ms(), clock) > weather_check:
print("pinging Open-Meteo")
# make the API request with function
# return weather ID, temp, temp color & hour
weather, temp, temp_color, new_time = get_the_weather()
# checks if it's day or night based on hour
# & returns day or night version of sprite
img = day_or_night(new_time)
label.text = " %s°%s " % (temp, temp_unit)
# reset clock
clock = ticks_add(clock, weather_check)
Scroll the Weather
The core functionality of the display loops continuously. The sprite is drawn to the 5x5 grid and is shown for five seconds. Then, the temperature text is scrolled across the display. Once the text finishes scrolling, the process begins again by drawing the sprite.
# draw bitmap sprite
draw_sprite(count)
# blocking delay to hold the sprite on the display
time.sleep(5)
# draw scrolling text
for v in range(2):
for i in range(text.width):
# Scoot the old text left by 1 pixel
pixels[:20] = pixels[5:]
# adjust color based on temperature
color = colorwheel(temp_color)
# Draw in the next line of text
for y in range(5):
# Select black or color depending on the bitmap pixel
pixels[20+y] = color * text[i,y]
pixels.show()
time.sleep(.1)
Page last edited January 22, 2025
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