LCD displays an "A" instead of 0
Here is my Suggestion: In cases a clear answer could not be seen, you have to remove any weaknesses step by step to further encircle the problem. Since there is now answer for more than a month, I assume this as an appropriate proceeding.

One weakness I see in your coding is, that you are counting your values x, a, b, up to ten and you are printing them bevor reseting them to Zero, so your are printing 'x' even if it is ten. If for any reason in the further handling your display shows HEX values, you will end up displaying an 'A'. Change your Code so that values > 9 are not printed out, than this weakness will be removed.