Not another IMU thread.

Faub

Edit: Added scanned schematic. Thanks for looking!

Hi guys,

After reading Ken's inspiring article about the downers of working in the business world I have decided to take a stab at a propeller IMU. The reasoning for my parts selection was I wanted a

-digital interface (I2C if I could)
-SD Data Logger
-USB Programmable on board
-Magnetometer (Backup for the GPS)
-Accelerometer
-Gyro
-Pressure Sensor
-External I2C Port and TTL Serial Out

I put each device on its own I2C bus after reading that if a slave is busy it could hold the clock line low and tie up communications. I wanted to communicate with each device to make it more fault tolerant on the control and software side. This is still a work in progress as I would still like to add some programmable pushbuttons and relay outputs. I am pondering also putting a 12 channel analog input on this board as well.

Do you think I should just make the IMU separate from the PWM in/out and focus on getting good measurements and add another cpu board for control? Or should I stack another prop chip on the IMU and load the pwm channels on there as well.

I am staring to be in more favor of the multi board approach since it mitigates destroying all my electronics in one shot. I am also considering making the power supplies separate. Attached is my first stab at a schematic. If anyone would like to double check my work I can provide the datasheets and diptrace file.

Thanks for looking!

Dave Hein

It would be nice to use the IMU either way -- as a complete controller, or as an independent IMU-only device. Could you attach the schematic with a higher resolution? Most of the labels are unreadable. If you can convert it to the GIF format it will take much less space than a 32-bit BMP file.