I have SX28 @20MHZ, baud rate "T115200" connected via serial to the BV4629 touch screen display and it is capable to determine auto baud rate by the first character received which MUST be a CR byte value 13.
My trays to establish communication was unsuccessful. The display presented the wrong baud rate value instead of the wanted one (115200). The seller-manufacturer suggested to me to do next:
"The logic is inverted, it should be +V when in the idle state, get your microcontroller to provide a non-inverted signal."
So I change "T115200" to "OT115200" and pull-up (4K7 resistor) line (sx TX_pin --> RX_pin on the display) but again, wrong baud rate values on the display.
Should I change the value of resistor? If so, how to calculate right one.
The only way I can control the display is "improvisation" as shown in attached SXB file.
The second problem for me is how to catch up incoming data(touched co-ordinates) without header byte.
More explanation in attached SXB file too.
TX_pin ---> RX_pin
RX_pin <--- TX_pin
RC.6 <--- Int_pin
Thanks in advance.