Solar Powered ESP32-C3-Mini Weather Station with DS18B20

Image of project

Schematic

Grafana Dashboard

Description

☁️ 🌀 🌊 ⚡ ☀️ ☔ ⛄ 🌁

This project is powered by a solar panel that charges a lithium ion battery through a Sparkfun "solar buddy" board. The code is written in MicroPython on an ESP32-C3-Mini. The microcontroller collects data from the rain, wind (speed & direction), humidity, pressure, and temperature sensors in a variety of ways (i.e. i2c, oneWire, ADC, and electrical pulse interrupts). The data is collected every 5 seconds, then averaged at the end of two minutes and placed into a dictionary data structure. The dictionary is converted to JSON and sent to my Wunderground PWS site https://www.wunderground.com/dashboard/pws/KFLJACKS4049 where my data and other users data get stored for public consumption. There is a Telegraf listener running in a docker container on my local network (repo for docker telegraf-influxdb-grafana stack -> https://github.com/jcksnvllxr80/docker-telegraf-influx-grafana) which takes JSON requests via API and converts the data into a protocol that influxDb speaks. There are two Telegraf outputs; one goes to the local influxdb running in docker and the other goes to a Prometheus plugin running in my Grafana Cloud account. Both databases allow me to make beautiful charts and graphs to show and analyze the weather data. All connections to the network are via Wi-Fi connection on my Google Wifi (Mesh) LAN.

Prerequisites

The following classes (which are all in this repo) must be manually loaded onto the esp32-c3 for this project to work (main.py also necessary):

• conf directory with 'config.json' inside... use the example i provided (will need to use an online converter to base64 encode your ssid and password)
• base64.py
• time_utils.py
• http_utils.py
• api_utils.py
• mrequests.py
• weather.py
• am2320.py
• mpl3115a2.py

Erase and flash micropython on the ESP32-C3-Mini from windows CMD

• download and unzip https://github.com/espressif/esptool
• download the MicroPython firmware https://micropython.org/download/esp32c3/ (esp32c3-20220618-v1.19.1.bin)
• for the next step I used anaconda prompt (you may have to install dependencies)
• python esptool.py --chip esp32c3 --port COM<your_com_num> erase_flash
• python esptool.py --chip esp32c3 --port COM<your_com_num> -b 1500000 --baud 460800 write_flash -z 0x0 esp32c3-20220618-v1.19.1.bin
• the above two commands worked for me but here is a helpful link just in case: http://embedded-things.blogspot.com/2021/10/flash-micropython-firmware-on-esp32-c3.html

TODO

• add ability to take asynchronous requests over network via API so that local nagios can query weather status
• get a UV sensor

Weather Vane voltage values and direction table

Dir	Ri	Vi	Angle	R	Vo	ADC
N	33000	3.3	0	33000	1.650	2335
N/NE	33000	3.3	22.5	6570	0.548	930
NE	33000	3.3	45	8200	0.657	925
E/NE	33000	3.3	67.5	891	0.087	123
E	33000	3.3	90	1000	0.097	140
E/SE	33000	3.3	112.5	688	0.067	300
SE	33000	3.3	135	2200	0.206	294
S/SE	33000	3.3	157.5	1410	0.135	190
S	33000	3.3	180	3900	0.349	494
S/SW	33000	3.3	202.5	3140	0.287	1516
SW	33000	3.3	225	16000	1.078	1525
W/SW	33000	3.3	247.5	14120	0.989	1400
W	33000	3.3	270	120000	2.588	3706
W/NW	33000	3.3	292.5	42120	1.850	2625
NW	33000	3.3	315	64900	2.188	3101
N/NW	33000	3.3	337.5	21880	1.316	1866

wunderground API call

learn more here: https://support.weather.com/s/article/PWS-Upload-Protocol?language=en_US

https://weatherstation.wunderground.com/weatherstation/updateweatherstation.php?ID=KCASANFR5&PASSWORD=XXXXXX&dateutc=2000-01-01+10%3A32%3A35&winddir=230&windspeedmph=12&windgustmph=12&tempf=70&rainin=0&baromin=29.1&dewptf=68.2&humidity=90&weather=&clouds=&softwaretype=vws%20versionxx&action=updateraw

GET parameters
NOT all fields need to be set, the _required_ elements are:
ID
PASSWORD 
dateutc
IMPORTANT all fields must be url escaped
reference http://www.w3schools.com/tags/ref_urlencode.asp
example
  2001-01-01 10:32:35
   becomes
  2000-01-01+10%3A32%3A35
if the weather station is not capable of producing a timestamp, our system will accept "now". Example:
dateutc=now
list of fields:
action [action=updateraw] -- always supply this parameter to indicate you are making a weather observation upload
ID [ID as registered by wunderground.com]
PASSWORD [Station Key registered with this PWS ID, case sensitive]
dateutc - [YYYY-MM-DD HH:MM:SS (mysql format)] In Universal Coordinated Time (UTC) Not local time
winddir - [0-360 instantaneous wind direction]
windspeedmph - [mph instantaneous wind speed]
windgustmph - [mph current wind gust, using software specific time period]
windgustdir - [0-360 using software specific time period]
windspdmph_avg2m  - [mph 2 minute average wind speed mph]
winddir_avg2m - [0-360 2 minute average wind direction]
windgustmph_10m - [mph past 10 minutes wind gust mph ]
windgustdir_10m - [0-360 past 10 minutes wind gust direction]
humidity - [% outdoor humidity 0-100%]
dewptf- [F outdoor dewpoint F]
tempf - [F outdoor temperature]
* for extra outdoor sensors use temp2f, temp3f, and so on
rainin - [rain inches over the past hour)] -- the accumulated rainfall in the past 60 min
dailyrainin - [rain inches so far today in local time]

mine will look more like this:
https://weatherstation.wunderground.com/weatherstation/updateweatherstation.php?ID=my_id&PASSWORD=my_key&dateutc=now&winddir=230&windspeedmph=12&windgustmph=12&tempf=70&rainin=0&dailyrainin=0&softwaretype=custom&action=updateraw

---

For testing chunks of code on the ESP32-C3-Mini

Use Thonny to write some code to ESP32-C3-Mini: example below where i was testing the temp sensor.

# 1-wire DS18B20
import machine, onewire, ds18x20, time
ds_pin = machine.Pin(19)
ds_sensor = ds18x20.DS18X20(onewire.OneWire(ds_pin))
roms = ds_sensor.scan()
print("Found ds18x20 devices: {}".format(roms))
ds_sensor.convert_temp()
time.sleep_ms(750)
for rom in roms:
  print(ds_sensor.read_temp(rom))

Star History