DIY home automation almost-instant-response WIFI smart switch for < $16 with MQTT

Parts list: AC/DC 12V 15W 1.25A “LED light strip” power supply – $2.33 Mini-360 DC/DC step down converter 4.75V-23V to 1V-17V – $0.62 Cactus Micro (Rev2) – $12(Alternative: D1 mini NodeMCU – $3.73, but my instructions below are for Cactus Micro) Relay – $0.60 Total: $15.55 ($7.28 if you go with the mini NodeMCU) WARNING!!! […]

“Sprinkler Brain” – Cactus Micro Arduino Wi-Fi multi-zone Smart Sprinklers (DIY for under $20)

In some parts of the world, water usage is serious business. For example, there is a drought in California. If you live here, you know that they want you to water your lawn only twice a week. And if they catch you using too much water, they slap you with a higher rate for being […]

How to flash espduino firmware on Cactus Micro ESP8266 rev1

Modify Cactus Micro: 1) convert default serial port to hardware serial (cut/solder) 2) connect Digital pin 5 to ESP8266’s GPIO0 (so arduino sketch at the bottom of this page can pull ESP8266’s GPIO0 to GND – this puts the ESP8266 in program mode to receive firmware update) Load Arduino programmer sketch – sends computer […]

Arduino Vader “Force Grip” remote car (a.k.a. smartphone virtual wheel)

The 3-wheel car is built with the Makeblock Robot Starter Kit. (Plus some Legos for style.) It has a Bluetooth module. It is controlled by the phone’s gyros via Bluetooth. You drive it like a steering wheel with two hands, or like Darth Vader with one hand. 1. Code for the smartphone below. I saved […]

How to build a Makeblock Bluetooth/WiFi Cellbot car

Ingredients: – LG Optimus Dynamic – PC game controller (joystick) – pygame for joystick input – python script runs on PC to translate joystick input to movement commands – SL4A to send movement commands from PC to smartphone over WiFi – smartphone sends movement commands to Arduino via Bluetooth (also SL4A) – Arduino translates commands […]