Software user

As I pointed out in my review on Safecast bGeigie Nano kit, the size of the current software already reached the limit of processor's program memory of 30KB or so. From this point on, it is difficult (if not impossible) to add new code features, and that may require drastic code optimization or even disabling existing features. I thought that the easiest solution to keep this project up-to-date is by upgrading the processor, by entirely replacing the Fio board with an ATmega 644P plus a few extra components (e.g. LiPo charger). This makes the kit a bit more challenging to build, since it requires soldering SMD components, but could also save a few bucks. The device is still Arduino-compatible and programmable, like to Fio, using the FTDI breakout . Updated Jul 11, 2014 : As Rob suggested, I added the XBee module as well. New Eagle files are here . This is how the bGeigie Nano Plus PCB looks now. (I also added an option for the Fastrax UP501 module, a bit cheaper then the Ultim...

I finally finished assembling, after more than a year, my bGeigie Nano . At over $400, this was by far the most expensive Arduino project I have built to date. The feature-rich open-source Geiger counter is offered as a kit by Medcom for the price of $450 (of which, $75 is donated to Safecast organization ). I stubbornly insisted on sourcing the parts on my own, to save a few bucks and to get a closer look at the process. Let me tell you: this may be the only kit out there where the components bought individually are as expensive as the kit itself! Obviously, this kit was not designed to make a profit. Here is a price breakdown (for non-believers): - PCB (OSHPark) - $17 (3 for $52) - Pelican 1010 box (store) - $13 - Arduino Fio  - $25 - GPS module - $40 - OpenLog - $25 - OLED display - $25 - laser-cut plates - $25 - sensor LND7317 - $150 - iRover HV supply - $35 - LiPo battery - $10 - SD card - $10 - other electronic components - $5 - hardware (standoffs, screws etc) - $5 - shi...

My " Remixed Geiger counter " board fits almost perfectly, by chance, in the "classic" Altoids box, with room left for the SI-29 GM tube, the 1100mAh LiPo battery and the 0.96" OLED display. The ATmega328 processor runs at 8MHz with the internal oscillator, a better choice (than the 16MHz of Arduino 2009) for the LiPo voltage of approx 3.7V.  The display I used is compatible with the monochrome 128x64 OLED display from Adafruit . It is powered at 3V3, requiring a voltage regulator ( 78L33 , TO-92), placed where the the trim-pot (for adjusting LCD contract) was supposed to be (top-right corner of the board). The sketch uses  Adafruit_SSD1306 library , with the wiring to the display as defined below: #define OLED_DC 8 #define OLED_CS 7 #define OLED_CLK 4 #define OLED_MOSI 3 #define OLED_RESET 5 Note that the same D3-D8 are used for connecting to the LCD 1602 display in the "regular" DIYGeigerKit . Also note that I did not install the "click" L...

One of the requirements I consider important when designing a device is the ability to repair it, in case it breaks down. This means that the device should be easy to dis-assemble into its components, ideally without using a soldering iron. To achieve this goal, I usually tend to use headers and sockets for connecting the boards between them. I also try to place the buttons/switches etc. directly on the board, eventually sticking out through holes in the panel, rather than using their panel-mount equivalents connected to the board with wires. The main reason I called one of my latest device "ugly" in a recent post was because I could not meet this requirement (well, I did not design the whole thing either). Essentially, that particular Geiger counter is very difficult to fix. Accessing to the FTDI header to re-program the Arduino Mini is also challenging. If, for some reason, the LiPo charger breaks down, the replacement miniature board would require drilling, then trace-cu...

Based on this photo from BroHogan's gallery of Geiger counters, it was supposed to be a simple encasing using Adafruit's Arduino enclosure . Everything looked neat and clean inside, even with room to spare. I wanted to use LiPo instead of AAA batteries, to avoid opening and closing the device every so often. This required the use of a LiPo charger, for which I picked the one I already had, the seeedstudio's  LiPo Rider . I spent countless hours trying to put this puzzle together: only 4 places for screws; small(ish) charger board must to be solidly anchored to the case (since an USB cable will be plugged in frequently), yet it does not have any hole for screws; 6 wires (battery, V out, switch) must be soldered to the charger SMD board; 12 wires need to connect the Geiger board to the LCD, on the other half of the case; trim pot suspended somewhere (since there is no room for it on the PCB); power switch to fit in the rectangular opening of the bottom ; When I thought I fig...

Updated June 2, 2017 - added VFD power supply with automatic dimming (#4 in the list below), contributed by Ken This is a superficial review of the few schematics I encountered while building Nixie clocks, VFD clocks and Geiger counters (no tube amplifier just yet). Although the schematics seemed basic at a glance, they usually ended up being a challenge (that is, they rarely worked right away) for me. That's another reason I am trying to cover them here, so I can use this post as consolidated reference any time I need it. Tubes require high voltage to work. Some ( Vacuum Fluorescent Display ) need 40V, others ( Nixie ) 180-200V, and some others ( Geiger ) even higher, 400-1000V. The high voltages are generated these days by switching-mode power supplies. Essentially, there is only a handful of popular solutions, and each DIY tube kit picks one of these, based on size, power requirements, cost. In principle, a switching mode power supply, also known as "boost converter",...

Today I found the time to complete the great DIYGeigerCounter  kit-based project, started a while ago . As I was writing then, assembling it was a breeze, even though the kit I had, courtesy of BroHogan , was version 1.0. The Geiger counter worked nicely as soon as I powered it from (approx 5V) battery: the buzzer clicked and the LED flashed, even faster when the radioactive mantle was nearby. And this is where I stopped. But the  DIYGeigerCounter  kit also offers the smart option of interfacing with an on-board microcontroller, specifically ATmega328, thus making it the cheapest Arduino-based Geiger counter available (compared to the Radiation shield from Libelium or Geiger counter  from Sparkfun). To finish this project, all I had to do was: connect the LCD display as detailed here ; compile the software, provided here , and upload it; find or make a practical enclosure; assemble everything together. The result is shown in the photo below. The case is a cheap...