Cactus

V1.0

🌵 Measure humidity in kitchen cupboards to keep food fresh 🍶

power LiPO
wireless WiFi
sensor Humidity
mcu ESP8266
ota? No
battery life 1 month
bom items 36
bom cost USD $26.92
vendors 5
status completed in May 2019
Prototype Front
Prototype Back
Prototype Side
Prototype Top

Downloads

Schematic Layout ECAD KiCad files Gerber files Firmware Test Web config Bill of Materials

Getting Started

Step 1

Setup an IFTTT webhook to receive a POST request with data and add a row to a Google Spreadsheet.

IFTTT

Step 2

Connect to the WiFi access point Cactus {UNIQUE_MAC_ADDRESS}.

Go to the web page http://cactus.local to fill in the WiFi credentials and IFTTT webhook key.

Access point Webpage form

Step 3

Press on-board button or wait for the Google Sheet to update with a new row with a periodic update to the cloud.

Google sheets

Maintenance

  • ⚠️ USB Connectors on WeMos D1 Mini vs WeMos battery shield
    • Do not plug in the USB cable on WeMos D1 Mini while the battery shield is on the PCB
    • Flashing firmware: Remove the battery shield from the PCB and use the USB cable on the WeMos D1 mini
  • Charge the LiPo by plugging in the USB cable into the battery shield