Difference between revisions of "BeagleBone/GeigerCapePrototype"
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Revision as of 21:44, 4 February 2013
|Matt Ranostay||Backup HW design/Userspace applications/Presenter|
|Dimitris Sapountzakis||HW design|
|Pantelis Antoniou||Cape Manager + DT overlay support|
Winner of Beagleboard.org Cape Contest 
The Geiger uses a simple circuit design (see references for schematic) and LND-712 tube but the magic is everything is an extension of Beaglebone + AM335x chip:
- PWM controls the boost converter
- Analog (AIN) feedback reports back current voltage of boost converter
- GPIO interrupts for radiations events
Future design work (some in progress):
- Fix current limiter with op-amps
- Use resistors that are within spec
- eCAP support to reduce the need of the pulse extender part of PCB, using a small ceramic capacitor versus 1 uF electrolytic one, and which in turn will reduce "dead time".
Geiger Cape kernel support is available in Beagleboard.org GitHub tree. There are demo applications available in the links below.
Communication with the cape is using Pantelis Antoniou's Capemanager + DT overlays driver interface (example output below):
Confirm Cape Manager picked up device # cd /sys/devices/ocp.2/bone-cape-geiger.11 (start running) # echo 1 > run (power LED turns on and the event LED lights up on a “click”) Display counts: # cat counter 4344 Display VSENSE (voltage feedback loop) in Millivolts: # cat vsense 538004
NOTE: These values may change if inductor on future revs is different.
|Name||Status||Duty Percent @ 20kHz|
ELC Europe 2012 Presentation
|Matt Ranostay||Beaglebone: The Perfect Telemetry Platform?|
Samples X11 + Python demo scripts + Schematic design: