This is my second attempt at making a balancing robot, I currently haven't started yet but I will be working with a lot of the original bits

Accelerometer - ADXL202
Gyroscope - ADXRS150
Gyroscope Evaluation Board - the same gyroscope but in a usable package - ADXRS150EB

Both of these parts are from Analog Devices, the accelerometer is available from RS and I imagine most other electronic suppliers. The gyroscope wasn't so easy to obtain, I ended up having to go through a company called Silica who eventually sold me one.

Gyroscope Accelerometer board

You can see the board I will be using to the left, the Gyroscope and Accelerometer have been fitted along with an op-amp, this buffers the analogue output from the accelerometer as it only really has a PWM output.

The Motors

This is the main thing that is changing, the previous motors were good but they weren’t precise enough, there was a large dead band which meant it took longer to react than it should.

Motors and Wheels

I am going to try and make use of the motors I bought for the first balancing robot but didn't use, they ended up being very underpowered, I am hoping this was because there was too much friction from the belt drive system.
I have connected the wheel axel directly to the gearbox shaft, this has been done by making a small coupling which slides over both rods and is pinned in place, this should give me a good connection without loosing any of the motors power.

The gear box wheel coupling