Quadcopter Controller Design Rev 0

Posted on Posted in Electronics, Projects

Now that I have a microcontroler I can desgin the rest of the controller. For the sensors I chose to use:

  • X and Y axis Gyroscope: Invensense IDG-500
  • Z axis Gyroscope: Invensense ISZ-500
  • 3 axis Accelerometer: Analog Devices ADXL335
  • Pressure Sensor: Bosch BMP085
  • Compass: Honeywell HMC5883

 

The Accelerometer and Gyroscopes will be used to control the rotational axis’. I chose to use analog snsors to beable to have the fastest update rate. Had I used I2C digital sensors the max possible update rate would be much slower since the ACD conversion time i significantly less than the time it takes to read data from an I2C sensor at their max baudrate of 400kHz. Thee are some downsides I am going to have to live with since I am using the analog sensors I need to have a stable and accurate volatge reference for the ADC, in whch I chose the:

National Semiconductor LM4132EMF-3.3

  • 0.5% Tolerance
  • 30ppm/°C  Temperature Coefficient
  • 50ppm Long Term Stability

Other downsides are to the anaog sensors are the 10bit ADC on the micro controller, which only gives 1024 counts which could be a problem. Also Analog sensors are going to be more suceptable to EMI which cold be thrown off from the brushless motors. Even though the downsides I finished the design with the analog sensors and sent the Gerber files off for the boards to be made.

Schematic:
Quadcopter Controller Rev 0

Quadcopter Controller Rev 0

Andrew