hello Bruce, thanks for your reply I am glad to hear that this AFE function is a useful function.

I don't mean to bother you but I have a few questions with this project. I am hoping to design my own PKE system, my plan is to create the base station with only the 125 kHz transmitter/receiver as I don't need the range of the UHF.

I am looking at the schematic of the transponder, I am guessing that I don't need to construct the "data_out" circuit as it seems to be for UHF transmission. Are any of the other circuits shown on this schematic not usefull for Low Freq talk back?

I also am looking at the source code file from microchip. I am familiar with mplabs and the different code platforms, but in the source file folder there are about 20 different asm files, do I need all of them and if so how do I implement all of them?

sorry this is turning into an essay, on the base station side once again all I need is the low frequency parts. So I won't need the LCD shown in the schematic or the circuit connected to "U4" as that is UHF I believe, I am not sure if there are any other parts I can omit in this schematic. And my previous question about the abundance of source codes applies to this part as well.

I am sorry to bother you with all these questions if you can't answer them due to the project you are working on now or you simply don't have time that is fine, but if you could provide me with some answers to these questions to get me up and running that would be great. I am hoping to build some circuits tomorrow and possibly get started on programming this weekend.

Thanks again Bruce