Garden Automation Part 2

The Raspberry Pi has IO pins left over after attaching it to the OpenSprinkler Pi and I am still waiting for my Pinoccio‘s to instrument my environment so I added a first yard sensor to the pi. It’s a DHT11 temperature and humidity sensor. Fortunately, pretty much all the work to get this connected to the Raspberry Pi has already been done. Consulting the pinout and using Adafruit’s interface program, I got my first data in minutes of work :-) Continue reading Garden Automation Part 2

DroidCycle: Motherboard Schematic

Image of moduleI want a featureful and easy to expand bike computer for my electric bicycle  and I have a high performance computer with a great display that I carry around with me all the time so I am developing an Android accessory bike computer, the DroidCycle. I already have an “off the shelf” motor controller handling all of the high power electronics and I have developed my own LED driver module for driving the headlights and taillights from main battery power. For the Android interface and handling all the realtime sensor monitoring and control, I have selected the mbed LPC1768 because it has an available library for the ADK and the online compiler means that 1) I don’t have to waste any time setting up the toolchain myself and 2) I can work on my firmware in wherever I am in whatever tiny scraps of time I have.

Continue reading DroidCycle: Motherboard Schematic

Blog syndication

This is a test! And also information. Since converting my website to run on wordpress, I have been playing around with various integration mechanisms, github twitter and google+. Twitter seems to work well enough for automatically tweeting when I post something. And it is possible to have google+ posts appear on my wordpress site but not the other way around which is a bit disappointing.

100V LED Buck driver

driver board with test LEDs
Here the driver is seen powering a string of 8 white LEDs in series for a total forward voltage of 27.2V from a 30V input at 15mA.

My electric bike is my primary mode of transportation so I need to be able to ride it under all conditions and at night that means I need light, lots of light. It seems silly to me to have a separate battery to power the lights when I have this nice big battery for the motor and it would be one more thing to remember to charge. The hiccup comes from the fact that the bike battery is at 48V (with a soon to come upgrade to 80V) so a switching power supply is needed.

Continue reading 100V LED Buck driver