MightyOhm.com

Yup, it is possible with HV Rescue shield and TQFP to DIP adapter!
I wrote short guide on how to do this, hope it's not against forum policy to link to my blog?

Hi,

I want to build a higher voltage version with 15mH inductor. But I don't know anything else about inductor, i.e. what tolerance should it be or maximum current. Anyone knows? Also source would be great, I wasn't able to find anything thru the hole on eBay

Curios if anyone tried making Scintillation detector? It's about 100x more sensitive than regular geiger-muller tube based detectors (scientists actually this tech to detect neutrinos too). It's based on scintillation crystals which generate a photon when it's atom is hit with gamma energy. Photomul...

You'll need to adjust the HV supply at each voltage. The 330 ohm resistor is more important when you're running at low voltages, below 2.4V. Do I still need to adjust HV supply if I do change resistor? Thanks for the info about 2.4V! I was wondering if I could run it on rechargeable batteries, whic...

Would this schematic work for dual voltage (3V and 5V) control? I plan to solder 2 small PCBs with 2 resistors and jumper in places of R6 and R11 so one can choose between voltages.
In fact I don't think one for LED needed, it will probably just be slightly duller with 300 Ohm in place of 100 Ohm..

Made slightly different adapter to connect geiger's pulse leads to iPad/iPhone for using with Geiger Bot I basically soldered together resistors and capacitor and used bunch of heat shrink tubing to hold it securely in place

Wow Tony, you are a legend!!! I didn't notice your post until now! Thanks so much, I'll try to get it working asap, just what I needed!

Perhaps it was value of the C1... I couldn't get it working until I finally gave up and bought some 56K resistors. Now it works like a charm

Update: Ok I was able to get Serial working. Just as I suspected PCB is labeled wrong, basically reversed. J7 jumper's left most pin (1) labeled with arrow is actually GND, and last one should be DTR (it's not connected anyway). So looks like schematic is correct but silkscreen is incorrect. Now I'm...

I finally got FTDI 3.3V adapter and setup XTerm as described, however I'm not getting any signal for Geiger counter on terminal program. Also tried with putty, it simply doesn't send anything to serial. I suspect that PCB might not be labeled correctly. It says GND by the last pin (6), but when I te...