This page provides links to downloading the software for the GK-B5 kit. and also describes uploading new software.
DIY Geiger invests a lot time and resources, not only in providing this open source code, but in its documentation.
Please support it by considering the original DIY Geiger Kit on this site, rather than knock-off versions that link to this page.
Changing the Software If you're familiar with Arduino then you probably know all of this.
The program ("sketch") that is pre-loaded on the Geiger kit's microprocessor has evolved to provide good functionality for most users. However, you may want to load the latest software on your kit, or even enhance or modify the default sketch.
The software is based on the Arduino. This is a development environment for microprocessors. The Arduino environment makes it easy to program the Atmega328 microprocessor that is on the Geiger board. It includes an "IDE" that lets you write, compile and upload your code to the chip from your computer. Best of all, the whole thing is free, open source. You will find tons of information on this, but you should start here.
I have made step by step instructions on installing the Arduino IDE and uploading new software on the GK-B5 kit. You can get it here.
USB to Serial Adapter (aka FTDI adapter):
The connection between your computer and the Geiger kit is made through a USB to serial adapter (dongle). These are sometimes referred to as an "FTDI breakout, board, or cable". One end plugs into USB on your computer and the other end plugs into the FTDI connector on the kit. On the computer side it makes a virtual serial port, and on the kit side it is TTL level serial (not RS232 level serial). Drivers must be loaded for your OS. On Windows they are generally installed automatically.
These adapters allow you to do two things:
There are a lot places to get these. Sparkfun and Adafruit make popular FTDI boards. There are also many on eBay but you should be cautioned that many of the low priced boards that use the FTDI chip have a counterfeit chip. These may work on older Windows OS's but may not on newer machines. (A genuine FTDI chip costs ~$4 in quantity so it's unlikely the $3 FTDI breakouts on eBay are genuine.)
There are other low priced Serial Adaptors on eBay that use a CP2102 chip instead of an FTDI chip. These will work, but may have a different pinout so they won't plug into the kit directly. You will have to adapt the pin out.
Bottom line is that it's best to buy a USB to Serial Adaptor from a local supplier with a genuine FTDI chip or one from eBay with a CP2102 (or similar) chip. Searching eBay for genuine FTDI adaptors or writing the seller is also an option. If you are in doubt you can write me.
Note: When you use a USB to serial device it will usually supply 5V to the kit. It's not a good idea to also power the kit with batteries at the same time. However, I've done this often with no harm.
Download the latest GK-B5 Software
This is about as far as I'd like to go regarding the subject of software. My sense is, that for some, the Geiger board may be an introduction into the whole world of microprocessors. I am truly happy about this, but if you need answers to questions about programming, adding new devices (WiFi, SD cards, etc.), and the like, your best bet is to use the Arduino forum.
Finally my apologies to the AVR Freaks out there, many of whom are sick about hearing about Arduino. (Although you're too smart to be reading this far anyway!) Just to say there are other ways to work with the Atmega328 on the Geiger board besides Arduino.
Here's a really old video that shows communication between the Geiger board and the computer . . .