Experimenting with SDR

July 18, 2012

I bought a MyGica TD312 from the Golden Computer Arcade in Hong Kong. It turns out that it is rtl-sdr compatible, but it only has the not-as-good FC0012 tuner chip.


Matthew Downing’s blog

June 16, 2012

Matthew Downing (our mechanical designer) now has a blog at mattdowning.wordpress.com.

Simulator for 485 network

May 5, 2012

In order to make debugging easier, I am modifying simavr to emulate the AVR 485 hardware. It isn’t complete yet, but some initial code can be found here. In the process of doing this, I found two possible issues with simavr. One is that the U2X bit is not being used properly in atmega328p. Another is that IVSEL is not supported. Both of these are fixed in my repository.

Mostly assembled new PR-lite

April 7, 2012

These were actually from quite a few weeks ago, but I didn’t upload them until now. Meanwhile, most of the hardware/firmware bugs are fixed.

Experimenting with the Cornell/University of Chicago jamming gripper

March 1, 2012

I tried building a gripper based on the following: home.uchicago.edu/~embrown/BRAMSZLJ10_PNAS.pdf

It was surprisingly easy to build and works very well for many objects.

Assembled new encoder board

February 27, 2012

This time with appropriately-sized photogates. The new linear actuator boards haven’t been assembled yet.

PR-Lite version 2 coming along nicely

February 25, 2012

Today, I finally made the firmware communication protocol work well without constantly producing collisions. As always, the code is on GitHub at https://github.com/someh4x0r. We have also begun putting together the new mechanical body.

Submitted new PR-Lite PCBs

January 11, 2012

Fixing all found problems (and unfortunately hitting Lunar New Year delays).

Linear actuator works

December 31, 2011

The v2 linear actuator controller (actually a reworked v1) has passed basic testing (extend and retract from CLI). All basic parts have passed basic testing now. This linear actuator controller works MUCH better than the prototype relay-based one.

Linear actuator v2 schematic

December 31, 2011


This is the schematic for the linear actuator board. It was requested by somebody on the HBRC group. This schematic should have the drain-source swap fixed, but IT MAY STILL HAVE OTHER ERRORS. The schematic is licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License.