Tinkerlog

For my latest projects I used a lot of single cell lipo batteries. They are really nice. High power density, low self-discharge, no memory effect and they can deliver quite an amount of current.
But lipo battery handling is a bit more complicated as with other rechargeable batteries. You have to take care of under voltage and over charging as that may destroy the battery.

I used the Sparkfun LiPoly charger, based on MAX1555, for some time and it works really well. The only thing I missed was a way to control the current. After some research I decided to try another chip, the Microchip MCP73833.

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Again a Braitenberg vehicle. This one is even smaller, than the previous one and comes on a custom PCB. It weighs 17 gramms, is driven by two pager motors, powered by a small lipo cell and controlled by an 8-pin ATtiny25V.

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Here is my very first article. It is published in c’t, one of the best known computer magazines in Germany. wOOt!

It shows some basic Arduino examples and how to build a Wiimote-like controller. The controller consists of an 3-axis accelerometer, a push button and an Arduino nano on a breadboard. This combination is used to control a Lunar Lander type of game, programmed in Processing.

• c’t article Shake, rattle ‘n’ roll, as full text
• wiki with more images, links and downloads

While we were at cheating, here is a new sticker for your notebook. It helps you to read and learn resistor values.

The first 10 direct messages to me will get one for free. And of course every next order at the Tinker Store will include one of these.

Last week I invested some time to solder 64 Firefly boards. Only 2.432 solder joints later I was ready for some videos.

Every firefly acts completely autonomously, it has its own tiny controller, eye and luminary. They are all connected for power supply only.

Here are some different configurations.

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Often, when I am tinkering with a controller on a breadboard, I have to open up the according datasheet, only to look up the pinout. So I designed a simple page with all of of the pinouts that I use most. It has:

• 8-pin AVRs, ATtiny25/ATtiny45/ATtiny85
• 20-pin AVR, ATtiny2313
• 28-pin AVRs, ATmega48/ATmega88/ATmega168/ATmega328
• Arduino to ATmega mapping
• ISP header, 6-pin and 10-pin
• FTDI-cable

Maybe it’s helpful for others as well. You can download it as:

• micro-cheat-sheet.pdf
• micro-cheat-sheet.svg

If you like it, you will also like the Tod’s cool Arduino chip sticker.

Update 2010/01/24

The new version includes the pinout of the Bus Pirate. Thanks Philipp for the update.

Here is the second incarnation of a Braitenberg vehicle. This one is almost half of the size of the previous one and it is programmed to “love”. That means it sticks to the light source and does not try to overrun it, as the “aggressive” first one.

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This is another breadboard compatible header board, that I am working on. This one is for all 28-pin AVR devices, ATmega48, ATmega88, ATmega168 and the latest ATmega328. Component count is low and there is no voltage regulator on board. That makes it easy to power it from various sources.

As a bonus, this board is a hybrid of through hole and SMT components. It has two SMD LEDs under the hood. Great to learn how to solder surface mounted devices.

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The Arduino can talk over a wide range of networks. Ethernet, Bluetooth, Wifi, XBEE and GPRS to name the most known. I had a Telit GM862-GPS module laying around, unused for some time already. It has GPRS and GPS capabilities, both accessible with AT commands. So I decided to port some of my code to the Arduino.

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If you want to play some retro arcade games, you will install the amazing MAME and run your favorite ROM. One of my best-of-all-times is Bomb Jack.

But you have to play it with the keyboard. Bah!

Or an USB game pad. Better, but still — bah!

Nothing compares to real arcade controls. And with a bit of tinkering, you can get a tiny step closer to the real gaming experience.

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