[Solved] Troubleshooting STC12C5A60S2 MCU RS-485 Baud Rate and Data Visibility Issues

Hi All,

I am looking for some help regarding the PARKING GUIDANCE SYSTEM (based on STC12C5A60S2 MCU - CHINESE Manufactured) with RS-485 interface for the PC serial /usb port, as well as for the attached Ultrasonic Vehicle / Car presence sensor with RED/GREEN LED indicator light modules.

The problem is that the mentioned Baud Rate (as described in User Manual) for both of the RS485 serial ports are 4800 for Sensor Port and 9600 for PC serial interface (via USB to RS485 converter / adapter), respectively.

But, using the standard SERIAL TERMINAL Apps for PC, e.g TERMITE, REAL TERMINAL and Advanced Serial Port Terminal, the DATA bytes received or sniffed at the connected RS485 serial ports are NOT visible, or readable in HEX or ASCII, since the MCU starts to dump the data after power up (e.g. ASCII syntax to scan connected sensors at the SENSOR INTERFACE SERIAL PORTs).

Pictures and the USER MANUAL are attached for reference only.

Any help regarding this issue shall be appreciated.

Best Regards,

Could you provide the specific configuration settings (e.g., parity, stop bits, data bits) you are using in the terminal apps for both the sensor port and the PC interface?
Karachi, Pakistan

Have you checked the physical connections and wiring for the RS-485 interfaces to ensure they are correct and secure?
Yes, tested with PC interface using NEW USB to RS485 adapter and SERIAL TERMINAL Apps, but no success yet. any Help is appreciated. Thanks

Thanks for the response and the shared link..

Already resolved the issue by removing the RS-485 IC and connecting the SERIAL Programmer using the ST MCU to the serial TXD & RXD pins on TTL levels & done the programming.

After successful firmware flash, the system is in NORMAL operation.

Thanks again.