BeagleBone/GeigerCapePrototype

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Revision as of 20:50, 4 February 2013 by Mranostay (talk | contribs) (Tubes Tested)
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Design

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 get rid of pulse extender part of PCB

Software

Geiger Cape kernel support is available in Beagleboard.org GitHub tree[1]. There are demo applications available in the links below.

Communication with the cape is using 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

Hardware

Tubes Tested

Name Status Duty Percent @ 20kHz
LND-712 Passed 60%
SBM-20 Passed 40%

Multimedia

ELCE 2012 Demo Picture
Video Links
Geiger Cape Sample App
CapeBus + Geiger Cape

ELC Europe 2012 Presentation

Matt Ranostay Beaglebone: The Perfect Telemetry Platform? PDF


Samples X11 + Python demo scripts + Schematic design:

Beaglebone Telemetry Presentation Resources


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