I have had success with getting PiBBOT to balance.
When I saw my first two wheel balancing robot I was very fascinated. And after receiving my Raspberry Pi, I decided to build one myself. PiBBOT (PiBalancing roBOT) is my first successful balancing robot. And it has room for improvement and extra functionality. When building PiBBOT, I had a few roadblocks I needed to overcome;
I originally had the Anker as the power source for both Pi and the motors, however the amperage was too low.
Original H-Bridge not powerful enough for my motors
Gyro calculation off by 15 degrees
The TFT displays the angles from the accelerometer, gyro, complementary filter and power to the motors. The buttons are to turn the motors on and off and to reset the gyro.
Incorporate the wheel encoders for better balance
Build a sturdier frame
Implement direction control
The able to self right itself after falling over
Retrieve a can of beer from the fridge
PiBBOT consists of these components; Adafruit: TFT; 2.2" 18-bit color TFT LCD display RF Receiver :RF M4 Receiver - 315MHz
Pololu; Motors; 9.7:1 Metal Gearmotor 25Dx48L mm with 48 CPR Encoder Wheels; Pololu Wheel 90x10mm IMU; MinIMU-9 v2 Gyro, Accelerometer, and Compass (L3GD20 and LSM303DLHC). Anker; Battery; Anker® Astro3 10000mAh 5V / 9V / 12V 2A Dual USB Output External Battery
Tenergy; Battery; 7.2V Tenergy 3800mAh Flat NiMH High Power
Here is my first attempt at getting PiBBot balanced.
This is a very early prototype, confirming that all the hardware works and the I can get the time of the main loop down to 20ms, which was easy. This prototype also helped me get my head around the code and math need to balance.
I am waiting on the delivery of some hardware to build my final and larger version. Which will have a battery pack placed up high, this will help a lot with the balancing.
The main components used to balance this prototype;
MinIMU-9 v2 Gyro, Accelerometer, and Compass (L3GD20 and LSM303DLHC Carrier)
Solarbotics GM6 120:1 Mini Gear Motor Offset Output
Dual H-Bridge Motor Driver
315MHz RF M4 Receiver
The receiver allowed my to change the PID values in real time.