Saturday, June 30, 2012

Modifying servo for continuous rotation and adding digital encoder - part 2



Now we'll add encoding capabilities to the servo so it can report it's incremental or/and absolute position. I'll be using AS5040 - 10-bit Absolute Programmable Magnetic Rotary Encoder with Incremental, SSI, and PWM Output from ams (ex- austriamicrosystems and TAOS) with incremental mode on, but if you care to re-program the device, it can feed you step/dir data. And if you modify PCB you can also use absolute position (that can be read through SPI as well as PWM/analog output).

What you'll need:

Friday, June 29, 2012

Modifying servo for continuous rotation and adding digital encoder - part 1

I need servo motors with position feedback for a project. I chose to go with servos and later decided to integrate encoder right into servo - I've seen something like this before (e.g. here:  http://www.openservo.com/ )

As I need quite powerful servos, I chose all-metal Power HD High-Torque Servo 1501MG from Pololu. In part 1 I'll just document how I modified it for continuous rotation - it seems everyone did that at least once these days (well, not particularly everyone - my mom still hasn't done that).
Power HD 1501 Analog Servo
Power HD 1501 Analog Servo

Thursday, June 14, 2012

MicroExplorer from STMicroelectronics - STM32 visual configuration tool

It's often a pain to properly connect different peripherials to an MCU, especially if the latter has rich remapping capabilities (that is definitely the case for STM32). I used to use MS Excel for playing with configurations for PICs but as I just started with STM32 it would be a nightmare to go through all the remapping info in Reference Manual and try to not assign the same pin for all the devices you want to connect your MCU to.

Luckily ST created a graphical tool for people like me.