Posted in Raspi, Sprinkler Projects on Apr 21st, 2013
I’ve made a minor update to OpenSprinkler Pi (OSPi), and the new version v1.02 has improved design of the separation pillars in order to make use of the screw holes available on Raspberry Pi rev. 2. See the picture below: This way, the Raspberry Pi rev. 2 can be more securely attached to the OSPi […]
Posted in LED Projects on Aug 15th, 2011
Recently I was looking for a cheap 16×2 LCD, and I found several interesting models on eBay that come with great price. I purchased one with blue backlight. The total is only $3.49 including shipping. The product was shipped from Hong Kong, so it took about 2 weeks to arrive. Here are two images of […]
Posted in Sprinkler Projects on Aug 21st, 2010
After finishing the previous minty water valve controller, I decided to make it an Arduino shield. This way, I can easily stack it onto other shields and extend its capability. I also added a few input buttons, and a DS1337 real-time clock, so that it can keep up with accurate time. Now the circuit has […]
Posted in Arduino on Aug 8th, 2010
At times I feel short of digital pins on the Arduino to handle multiple button inputs. Here is an easy way to use 1 analog pin to handle many input buttons. The way it works is very straightforward: use a resistor network as voltage dividers, and then let each button feed a different voltage to […]
Posted in Sprinkler Projects on Jun 14th, 2010
I’ve always been fascinated by minty projects — circuits that fit neatly into a mint tin. There is an entire webpage on Make that documents such projects. For a long time I’ve been thinking of my own minty project: what can I build in a small mint tin? Recently an idea came up: I had […]
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