LEGOtiny

After my last Mini RC Car project I knew I wanted to make a smaller better one.  Some months later and this is the result:

The reason why this one is in a LEGO body is because of this question on LEGO Stack Exchange where it was asked if it was possible to power the small LEGO City wheels.  At that point I had already started playing with micro DC motors and I also started using the ATtiny chip.  This was a perfect storm.  I had to build a super small LEGO vehicle.

Here are all the parts needed to make this build:

• Set of gears from a race track car
• LEGO wheels set
• LEGO brick 2x2
• Micro motor
• 0.1uf capacitor
• Transistor
• Diode
• ATtiny
• Socket
• Power adaptor

I'll go over the small details in an Instructables ASAP.  For now here's shot from the inside:

Here's a video where I show the final result:

Jumping on board

Here his a 'how-to' for running two low voltage (3.3V) micro controllers on a breadboard.

The first one is the chip(s) used with the TI LaunchPad. I've tested this setup with the MSP430G2211 and the MSP430G2231. The chip will run at 3.3V and is rated up to 3.6V.

This setup needs a 100nf capacitor between pins 1 and 14, then pin 10 needs to be connected to positive using a 47k resistor.  I use the LaunchPad board to program the chip before transferring it to the breadboard and this is pure laziness since there must be a way to program it in place.

The second one is the ATtiny (in this case the Attiny13) which can run the same code as the Arduino (ATmega328) and can be programmed using the Arduino IDE and uploaded using the Arduino board as an ISP for ATtiny.  You will find all kind  of help online for using the ATtiny13, ATtiny45, ATtiny85, ATtiny44 or ATtiny84.

The chip will run at 3.3V or 5V.  As you can see by this diagram, this is the most simple one to use.  No crystal and no resistor are necessary for running it.