Step 5: Detect Radiation
Once the arduino has been programmed, you can run the processing sketch. The geiger counter should detect about 20 counts of radiation a minute, as natural background radiation. This equates to about 5 bits a minute, which is pretty slow. To increase the number of counts per minute, I bought salt substitute, which contains potassium chloride. A small percentage of potassium atoms are naturally radioactive (its still perfectly safe) , and we can actually measure the increased radioactivity with the geiger counter. I was able to get up to 60 counts per minute, or a bit over twice background radiation (again perfectly safe). The increase in radioactivity allows the counter to produce bits at a faster rate.