Figure 8 CPS range display chart for Analog Digital Meter.
Switching from Imperial to Metric Measurements
If one places a jumper on the two pin header on the back of the Analog Digital Meter, the display will change from imperial measurements mR/hr to metric measurements mSv/hr. The mSv/hr is shorten to mS to fit on the 8 character line. The CPS reading stays the same regardless whether meter is set for imperial or metric.
Building the 8x2 LCD display:
Because the LCD is connected to and powered by our main Geiger counter board, there are a few components we can eliminate from the pcb and simplify its construction. The power and backlight switches S1 and S2 are eliminated and replaced with a jumper. Since we are pulling 5 volt power from the Geiger Counter board, we can also eliminate the voltage regulator U1 and input capacitor C2 shown on the PCB. What's left is a spoonful of components to mount to get the 8x2 LCD Analog and Digital Meter working. Figure 9, is the Analog to Digital PCB for the 8x2 LCD.