BL4S200 RS232 port F crashed

Rabbit
1

I had a problem with the PORT F after a surtension on a lcd display.
The port E is used so i need an other port RS232
There is an extension for the BL4s200 for new port RS232

Thanck you for the help

2

The BL4S200 only has two RS232 serial ports (E and F), but looking at the BLxS2xx schematic, it appears that you can use serial port B in SPI mode over the same lines (TXE, TXF, RXE). Doing so would interfere with using serial port E on those pins.

How did you damage serial port F? It seems odd that serial port E works when both ports use the same transceiver (U20) for I/O. Maybe you could replace U20 to restore functionality to serial port F?

Serial port C is RS485. Serial port D is (I believe) RS422 signaling (or some sort of differential SPI) running on J6 and J8.

3

Thanks for your response

I replace with this BL4S200 an BL2665 very old ( 2007)
On this BL2665 i have problem for load the program.

On the BL4S200 i use the port E for a GSM modem and the port F for a lcd display.
The dispay is supply at 5Vcc by a 7805 regulator.
So the regulator crashed and the port F don’t work.

I don’t see the U20 on the card but i suspect it’s a CMS and it’s difficult to change.

So i look for the SPI mode .

Thanck you Alain Rizzo