Page 1 of 1
Using Bluetooth on MightyOhm Geiger Counter?
Posted: Sun Mar 30, 2014 11:01 pm
by PiledHigherDeeper
Hi all - I have one of these little guys:
http://www.ebay.com/itm/Wireless-Serial ... 1173wt_952 to connect my MightyOhm counter (eventually) at the serial out, wirelessly... Anyone do this on a Mightyohm Counter? Any thoughts? I would LOVE to use this means to talk to my iPad and GeigerBot, wirelessly vice using the audio/mic cable, but I don't know if that will work...
any thoughts appreciated!
Paul, Flagstaff, AZ, NT3L
Re: Using Bluetooth on MightyOhm Geiger Counter?
Posted: Tue Apr 01, 2014 7:45 pm
by mightyohm
It will work, with one exception - there is not enough voltage available on the kit unless you add an extra battery or other power source.
The pinout for J7 is:
1. GND
2. GND
3. NC
4. RX
5. TX
6. NC
There is no VCC on J7. You'll have to connect the VCC pin of the bluetooth module to a 3.6-6V power source.
Re: Using Bluetooth on MightyOhm Geiger Counter?
Posted: Thu Apr 03, 2014 11:27 am
by PiledHigherDeeper
hmmm- so let me ask, what might be a better battery source for BOTH the Counter, and siphoning off 5vdc for the Bluetooth -
4 x AAA or AA holder (the biggest that fits in my box, and attach a TO-220 style 7805 voltage regulator, and pull off 5 VDC for BOTH the counter and the BT (ie, will the counter handle 5 vdc OK),
OR,
1 x 9VDC battery with this kinda regulation using a 7805 and the ole basic reg ckt:
http://www.learningaboutelectronics.com ... -a-circuit... less mAh this way, ....
Your thoughts?
Paul Flagstaff AZ
Re: Using Bluetooth on MightyOhm Geiger Counter?
Posted: Thu Apr 10, 2014 2:20 pm
by mightyohm
I would power everything (the kit and the BT adapter) off 3xAAA batteries (nominal 4.5V).
You should probably put a series resistor (1k?) or voltage divider on the serial TX line to the BT module because it's only spec'd for a 3.3V logic level.
Re: Using Bluetooth on MightyOhm Geiger Counter?
Posted: Tue Apr 15, 2014 1:08 pm
by ndolezal
PiledHigherDeeper wrote:Hi all - I have one of these little guys:
http://www.ebay.com/itm/Wireless-Serial ... 1173wt_952 to connect my MightyOhm counter (eventually) at the serial out, wirelessly... Anyone do this on a Mightyohm Counter? Any thoughts? I would LOVE to use this means to talk to my iPad and GeigerBot, wirelessly vice using the audio/mic cable, but I don't know if that will work...
any thoughts appreciated!
Paul, Flagstaff, AZ, NT3L
Author of Geiger Bot here... no-go on the iOS compatibility I'm afraid. Only currently operable Bluetooth mode is HFP (hands-free profile / headset) using analog audio DSP. Relatively high power use, 8 kHz max sample rate. (ie you may need to increase the pulse width)
All other non-LE Bluetooth on iOS (and USB) such as serial IO is locked down with encryption via Apple's "Made-For-iPod" program. Bluetooth keyboard input only works with text boxes, problematic / buggy if you try abusing that.
Bluetooth LE is open, actually very well implemented. But it's not currently supported by the app. There is no standard protocol for exchanging radiological data, the base LE profiles are heart rate (fitness) and temperature. So that's per-model support / "drivers".
Actually if you have the counter output as a Bluetooth LE heartbeat sensor (CPM -> BPM) you could probably use any number of apps to display and log the data. Not sure what happens if you go past the tachycardia range though.