Recently I was involved in a project that requires reading data from a personal weather station (PWS) installed at a friend’s backyard. If you search for “personal weather station” you will find plenty of off-the-shelf products manufactured by various companies....

Can’t believe I have been silent on this blog for more than a year now. I would really like to get back to blogging more regularly, and hopefully this post serves as a good starting point. As the first order...

When designing electronic circuits, often it’s necessary to have a proper enclosure for the project, to protect the circuit board and components, and for aesthetic reasons. There are several options to choose from. For example, if this is a one-off...

Recently when helping a customer, I came across an interesting case of how to control Gardena 1251 latching solenoid valve using OpenSprinkler Bee. This valve is mostly sold in the European market and isn’t very popular in the US market....

Today I am very excited to introduce OpenSprinkler Bee (OSBee) 2.0: it’s an open-source, WiFi-enabled, universal sprinkler controller. It is suitable for garden and lawn watering, plant and flower irrigation, hydroponics, and other types of watering project. This is the...

A quick note that our Black Friday / Cyber Monday sales are on now: all OpenSprinkler products are shown in discounted prices right now, and the deal only lasts till Monday Nov 28. This is the only time of the...

Last Thursday I had a lot of fun doing a workshop at my college where I taught students to use a WiFi-enabled Color LED matrix combined with Javascript programs to create animations displayed onto the LED matrix. The matrix is...

I just discovered something exciting recently and want to share with you: it’s now possible to use IFTTT with OpenSprinkler and OpenGarage; and because IFTTT support Amazon Echo (Alexa), you can now speak voice command to trigger sprinkler actions. For...

A few years ago I purchased a NeoDen TM-240A desktop pick and place machine, and wrote two blog posts about it. It was one of the most popular desktop pick and place machines on the market back then, and has...

For a long time, OpenSprinkler Pi (OSPi) has been using the OpenSprinkler injection molded enclosure. While this has worked fine, the enclosure is not particularly designed for OSPi, leaving some cutouts not aligned with Raspberry Pi. Recently I have started...

As a kid I was fascinated by the Crystal Radio — the simplest radio that requires no battery or power source. Learning about crystal radio is what got me into electronics in the first place. There are plenty of tutorials...

After I released the ESP8266-based OpenGarage, there has been a weird bug that kept bugging me: a small fraction of the controllers (let’s say 1 out of 10) would crash on restart, and that leads to an infinite reboot cycle....

Today I am very excited to introduce you to OpenGarage — an open-source, universal garage door opener built using the ESP8266 WiFi chip and the Blynk app. I’ve wanted to finish this project for a while, as there have been...

My fortune cookie last night said I have recently left many things undone, and at this rate I may never get them done. Quite alarming indeed. One of the things I haven’t done well recently is regular posting on this...

After several months of continued development, I am excited to announce the release of the first DC powered OpenSprinkler — v2.3 DC. This version uses a 9V DC universal power adapter, and is designed to work with both standard 24V...

For the past two weeks I have been traveling in China, and I spent the entire last week in Shenzhen, the city known for electronics supplies, assembly and manufacturing, among many other things. I visited Shenzhen two years ago, and...

Just a quick update: we are at the Bay Area Maker Faire 2015, station 2, booth 2542 (next to the game of drones). This year Samer is also joining me at the booth, so it’s gonna be great We are...

This post is a quick update on the recent development of ESPToy. I made a video and here is a brief summary of what I covered: New version 1.22 which has added LiPo battery jack and charger (see previous announcement...

We have a number of overstocked printed circuit boards (PCBs) which I’ve listed on the shop page for sale. These are official PCBs used for our products, and are great for your prototyping need. They are all less than 40...

Since March this year, orders of OpenSprinkler have been increasing rapidly. Within a couple of weeks, we’ve done two batches of OpenSprinkler 2.3 at our local manufacturer — Worthington Assembly Inc. (WAi). Previously I have blogged about OSPi manufactured at...

Since the first version of ESPToy, I’ve done some pretty rapid revisions. This post is to introduce the new minor revision 1.21, with LiPo battery jack and charger. As you can see in the annotated diagram below, the main components...

A little while back I released the very first version of ESPToy — a ESP8266 Development Board with a few useful on-board components like color LED, button, and temperature sensor. It has a built-in ATmega644 microcontroller, and pin headers for...

Hey, it’s March already, that means spring will be here soon! Amid an unusually cold winter and freezing weather this winter in New England, we’re finally starting to see some warm winter days. No more snow please, we’ve had enough...

Around Thanksgiving last year, I received a request from a biology lab professor who commissioned me to modify OpenSprinkler to become a custom fluidics controller. The goal is to achieve web-based, programmable control of fluid selector valves, linear actuators, relays,...