“MyGeiger” is a premium quality Do It Yourself Geiger Counter Kit with PIC16F876A and Nokia 5110 graphic LCD. The kit require good soldering skills and ability to read and follow user manual. MyGeiger Kit can be ordered as a soldered module, with minor solder work has to be performed by the customer: soldering tact switches, battery holder wires and connecting external components. Please choose assembling option from drop down menu. GM tube, enclosure, TTL module and battery are not included. You can add Geiger Tube from the catalog to the order or purchase SBM-20 on eBay.
MyGeiger hardware has straightforward PCB design with LCD installed over the components, 3 tact switches for controlling the program and several functionality pins such as UART, alert pin, tube events and audio output. MyGeiger can be used as a personal dosimeter or as a radiation monitor hardware with our freeware Radiation Logger Windows software or with other compatible computer program.
Geiger Counter software control 400V high voltage stabilization for GM Tube. Tube voltage value is monitored and corrected by microcontroller even when battery capacity goes down. Calibration menu allows adjustment of conversion factor, alert threshold and choose battery type. The display of the digital counter is auto-range and includes CPM value, radiation dose, fast scale bargraph, measurement time countdown, GM tube high voltage reading, sound and battery indicator. In compare to other Geiger counters kits with graphic lcd on the market, "MyGeiger" has extremely small power consumption. All board has only 10-12mA power consumption and can operate during several days when powered on battery.
Since 1.03 firmware version "MyGeiger" has moving average algorith for calculating CPM (counts per minute). When testing radioactive samples or background you'll need to wait up to 60 seconds to get full results. If radiation goes fast up then alert system will inform you immediately with activating logic 1 level on alert pin, with graphic bargraph and lighting up LCD backlight for visual signalization.
As you should know, every SBM-20 tube may have 10%-20% CPM error tolerance, some samples even more. MyGeiger has calibration menu where user can adjust tube conversion factor and eliminate GM tube error influence for displayed dose. The factor can be adjusted between 0.0001 to 0.0250 when default value for SBM-20 is 0.0057. You also can use any other GM tube 400V tube model, for example SI29-BG, M4011, SBM-19, SI-180G and more. The important note that is only SBM-20 tube is garanteed to be installed into PCB clips, other tubes will require wire connection.
The video demonstrate 1.03 firmware program. The kit shipped with the last available program version at the date of purchase.
Because the project developed mostly for DIY, you'll need to find a proper enclosure for your counter. RH electronics has "Gallery" page where published finished projects photos. You are invited to send your work photos to join the gallery.