Many times people want to monitor the AFR but want something compact, a standalone meter.
In doing research on AFR meters I found that these meters only monitored 1 02 and were not very accurate.
I decided if I had such a meter what else would I want it to include so I designed a dual 02 AFR meter.
It attaches to 2 02s output wires and via a slider switch will report via 20 LEDs using 3 colors to 1 of the 02s, slide switch to position 2 and see other 02's values or slide to position 3 and it averages both 02s output and displays that on the LED bar.
Also made sure outpput of 02s were clean and any noise was weeded out so LEDs report accurate values.
Here is what it looks like :
This way the user can check to see if both front 02s are reporting the same, if one has gotten lazy or 1 head leaner/richer then the other and have the meter average both sides and report the AFR average.
Size of PCB is 2 1/8 X 3 inches.