Those readings definitely seem strange to me. I expect a diode drop of around 1.2V across each IR emitter, for a total of around a 6V drop across all five sensors (with the rest of the 9.25V drop happening across the emitters’ current-limiting resistor).
It is odd that the sensors worked for you initially and then stopped working after reprogramming. Did anything else happen between your successful test and your first failed test?
- Ben
Dear Ben and Ryan,
I fixed the problem. Actually, the problem was PC3 so I removed that one and I soldered by new single QRT. Now it is working properly. Thanks a lot guys for your kind cooperation.
Cheers,
Amir
I’m glad to hear you were able to identify the problem and fix it; that was very resourceful of you! Thank you for letting us know that the problem is now resolved. Where did you get the replacement reflectance sensor?
- Ben
Dear Ben,
Thank you very much. I had a QRT8 RC Sensor array that I bought it from Lawicel webshop long time ago so I removed one of them and used in 3pi. 
Best Regards,
Amir
