Cect T689 pinout
 

pls help my mpeg 4 cect T689 with bt with this pin out not work .

hello!

this pins work good, just please note:
phone Tx must be connected to box Rx
and otherwise: phone Rx to box Tx

for work with first MCU use Txa, Rxa pins.
to work with second MCU: Txb, Rxb