I have a Byron SX1/SX11 wireless door chime and I'd like to replace the ding dong with a small MP3 player so that I can use any sound I like.
I believe the ding dong comes from the TC 4069 UBP chip. So the question is can I use this piece of kit to create the MP3 door chime by simply bypassing the chip and if so how would I go about it?
Um, no. The 4069 will be used as an amplifier to increase the signal from the RF receiver. The extra pcb (mounted in the main pcb) with the epoxy blob will be the ding dong sound generator. One of the connections to that pcb will carry the code to trigger the chime.
Your best bet is to use the LED output - I assume it goes on when the chime sounds, no? You could connect an optocoupler in place of the LED to give you a sort-of switch-like output. How you connect that to your MP3 player, I'm not sure.