Raspberry pi robot: real-time object detection using remote Tensorflow server

Finished product first: The video above shows real-time objection detection using a neural network model called Single Shot MultiBox Detector (SSD). The neural network model was trained on (and runs with) Tensorflow. The “AI” model works much better than older Computer Vision (OpenCV) techniques. For example, here’s an example of a previous attempt to track […]

How to make a webapp/server that can read & react to emails

In the last post, we talked about how to teach your Google Home device (or Google Assistant on your Android phone) to send emails. But that itself is not too interesting (unless you really enjoy spamming yourself). What would be more useful is if you create a program to read and act on the emails […]

How to send emails with Google Assistant / Google Home

I got a Google Home Mini for $19 last Black Friday, and my family has been having fun with it. My kids like to ask it questions and play music on it. I’ve set it up with voice shortcuts so my kids can say, “Call mom” or “Call dad” to phone me from the Google […]

How to start using NodeMCU for WiFi projects (Goodbye Arduino?)

Ah Arduino. You were my first gateway to making tiny electronic widgets that interact with the world. I’ve played with platforms that range from small and simple to expensive and complex like FPGAs, but nothing beats the cost and ease-of-use of Arduinos for making tiny devices you sprinkle around your home. Until now… See the […]

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: http://blog.aprbrother.com/p/283 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 […]

DIY Electric Imp WiFi garage opener + sensor for under $50 (weekend project)

Background story / motivation One night, I opened my garage door to take out the trash. Then I came back in and went to bed. The next morning, as I was strapping my son into his car seat, he asked me, “Daddy, why is that exercise ball over there?” “What? What exercise ball?” “That one. […]