Tuesday, July 30, 2013

Oversampling, Decimation, Filtering

To convert Sharp IR Rangers to I2C, I now use an ATtiny44a for signal processing.

Sharp Range Sensor I2C Adapter prototypes.
The new approach, guided by Atmel application note AVR121 (pdf), works much better than the dedicated ADCs I was using and will form the core of my Sharp I2C adapter, after I make a few usability tweaks and finish the firmware.

Read on to see how I improved performance with oversampling and filtering.

Thursday, July 25, 2013

Still away on personal business

Life is still kicking me and my family down pretty hard. As things return to normal, look forward to all kinds of electronics fun:
  • Digital oversampling and filtering with ATtiny,
  • Logic analyzer shootout: Seleae Logic vs. Open Bench Logic Sniffer vs. HP1650A,
  • ATtiny85 serial with USI (Universal Serial Interface),
  • Building a pseudo-theremin with Sharp Rangers,
  • Servo City's Actobotics building system,
  • Hopefully the August SHARC line following competition, and more;
  • I'm always working on at least a half-dozen projects. :)
Thanks for sticking around. Sometimes life beats you down but you have to keep fighting and get back up and push forward.

Thursday, July 18, 2013

Rover RC Multiplexer

Safety switch? Takeover circuit? RC Mux? Kill switch? Whatever it's called, this circuit is how you take over control of your autonomous rover milliseconds before it crashes itself into a curb, lake, or ankle. And I've just redesigned mine. Here are the deets. (Meanwhile, it's now for sale on Tindie)

Tuesday, July 16, 2013

Away on personal business

I've been indisposed for three weeks on personal business.

Don't despair, I'll have several projects to write about soon when things settle down.