IOT weather display for Ecowitt devices using Inkpad2.
SERVER
Ecowitt sources (e.g. WN36 array, WN34 temp sensors)
measure weather variables and send via. rf 866 mhz (OTA up to 100m) to Ecowitt sinks
Ecowitt sinks (e.g. WS3900 console, GW1100 gateway)
package variables and send in Ecowitt format using http (Wifi network) to ecowitt2mqtt.py (on server)
ecowitt2mqtt.py (on server)
transforms and sends variables (as JSON) using mqtt publish (localhost) to mosquitto (on server, as mqtt broker)
mosquitto (on server)
acts as mqtt broker for ecowitt2mqtt.py, nodejs app, and any other clients
nodejs app w/ express (on server)
receive and cache variables (as JSON) using mqtt subscribe (localhost) from mosquitto (on server, as mqtt broker)
respond to http request (WiFi network) with cached variables (as JSON) to clients (e.g. Inkplate2)
provide human readable (live refreshed) web interface for cached variables
provide configuration variable mappings to multiple clients based on MAC address
store firmware from development tools and provide firmware checks and updates to clients
CLIENT
Inkplate2 (Arduino ESP32 w/ WiFi, battery and case) -->
wake up from deep sleep every N=5 minutes
connect to WLAN
if not configured, request configuration from server
request variables (as JSON), served by nodejs app
render selected variables into epaper display
periodically check and update firmware if required
deep sleep w/ wake up alarm
In this case, the server components (ecowitt2mqtt, mosquitto, nodejs) are housed on a Raspberry Pi Zero (32 bit) running DietPI with an Ethernet HAT, paired with a Ecowitt GW1100 as a sink, both of which are mounted outside (for proximity to sensors in a lake) in an IP67 case and powered by PoE. There are two other sinks (WS3900 consoles) inside separate houses that are also delivering to the server.
This is a really simple Arduino ESP32 based e-paper device with built in battery and WiFi (b/g/n) housed in a 3d printed case. The 2.13" screen resolution is 212 (width) x 104 (height) at 111 dpi supporting three colours: white, red and black. The USB-C port is for charging and communications. The provided battery is 600maAh.
Inkplate2 (with case & battery) -- https://soldered.com/product/inkplate-2
Raspbery Pi Zero H (WiFi version not needed) -- https://www.aliexpress.com/item/1005007064834607.html
Waveshave Ethernet/USB Hat -- https://www.aliexpress.com/item/4000022488083.html
MicroSD card (4GB minimum, I'm using 16GB) -- https://www.amazon.co.uk/dp/B07DVG12SF
Ecowitt Gateway GW1100 (WiFi only) -- https://www.aliexpress.com/item/1005005264135330.html
Generic 10/100 POE splitter -- https://www.aliexpress.com/item/1005004230399849.html
USBA splitter (for POE splitter to both Zero and Gateway) -- https://www.aliexpress.com/item/1005006147721647.html
USBA to Micro-USB (to power the Zero)
IP67 box 200x120x75 (for external mounting) -- https://www.aliexpress.com/item/1005005367221276.html
If you use an external PoE cable, make sure to isolate the Ethernet cable on entry to your property, and preferably use shielded cable and ground the shielding. Do not ground these to your electricity supply ground, but ground directly to earth bonding.
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DietPI (as base system) -- https://dietpi.com
ecowitt2mqtt -- https://github.com/bachya/ecowitt2mqtt
mosquitto (for MQTT broker) -- https://github.com/eclipse/mosquitto
avahi (for multicast DNS) -- https://avahi.org
http-server (nodejs + express + modules) -- https://nodejs.org
upnp update scripts
Sources: https://github.com/matthewgream/weather/tree/main/server
Install DietPI then the software components including systemd service scripts and defaults. The system is minimal and all processes, including server components, run as root. The MQTT broker is not password protected. The server publishes itself as 'weather.local' using mDNS via. avahi. UPnP is used to configure an inbound sshd gateway. Configure sshd as public key authentication only -- no password. The Ecowitt sinks must to be configured as per ecowitt2mqtt instructions. The sinks can still publish to other services including Ecowitt itself.
Arduino IDE -- https://www.arduino.cc/en/software
ArduinoJson library -- https://arduinojson.org
Inkplate2 library -- https://github.com/SolderedElectronics/Inkplate-Arduino-library
flashz -- https://github.com/vortigont/esp32-flashz
esp32fota -- https://github.com/chrisjoyce911/esp32FOTA
Sources: https://github.com/matthewgream/weather/tree/main/client/Arduino
The client software builds under Arduino IDE and is simple in execution as below. Note the intent to minimise wifi enablement time and power on time to conserve battery, and to only refresh display if network update succeeds. Initial testing with a 5 minute update interval resulted in a life of 6 days and 17 hours (161 hours, 9687 minutes), which at 5 minute intervals is 1937 updates, before the battery was exhausted. The standard Inkplate library has been included and stripped down to remove unneeded modules (e.g. JPG, PNG and BMP images, and colour dithering), but the code will build against the standard library. The files Secrets.hpp (in the Arduino project folder) and secrets.txt (in the server config files) have been suppressed from the repository for obvious reasons. If the client does not have any configuration, it will request from the server keyed upon its MAC address. Periodically, the client will check the current firmware version and download any updates.
Note the Arduino IDE scripts that automatically transfer new firmware versions to the server and store them compressed.
