Configuring AT89C51RD2 for RS232

[jeff7tg]

I have a AT89C51RD2 microcontroller but accidentally disconnected a VCC or GND to pin connection and now RS232 communication is not possible. I do not remember what the connection was exactly but it was VCC or GND to some pin. Does anyone know what the connection could be? I am using a plain RS232 cable.

My final goal is to load a hex file using FLIP to the microcontroller.

I am not familiar with hardware at all so please forgive me if my description is severely lacking.

 

[djc]

See if micro controller is properly resetting or not. Or use USB to serial converter and connect Rx and Tx pin directly to micro controller.

 

[jeff7tg]

See if micro controller is properly resetting or not. Or use USB to serial converter and connect Rx and Tx pin directly to micro controller.

Thank you for replying. Unfortunately, the USB to serial converters I have are defective, so I can only use the serial cable. I do not know how to check if it is properly resetting. This is what the microcontroller and board look like:



The connection that was removed was in the white section.

 

[hobbyckts]

What connection removed in the board? Whether it is a wire connection or PCB track cut or any pin breakage in controller? Your image is not quite clear...

 

[jeff7tg]

It was just a wire conection

 

[jeff7tg]

I have a functioning usb to serial converter now. However, there are coupling nuts attached to it and my serial device has coupling nuts as well so I cannot connect them. I do not think the nuts on the converter are removable. If I remove the nuts on my device, will it be damaged?

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[ads-ee]

It's not likely to be damaged removing the nuts, but if it's like most of those type of connectors the nuts are the only thing keeping the metal shell connected to the nylon/plastic part.

 

[jeff7tg]

It's not likely to be damaged removing the nuts, but if it's like most of those type of connectors the nuts are the only thing keeping the metal shell connected to the nylon/plastic part.

I see what you mean. Is the metal shell quite necessary?

 

[ads-ee]

Unless you want a loose dangling connector that will likely break after a few uses, then yes you want the shell firmly mounted to the plastic.

Most of the time when I've seen stuff like this where clearance would be an issue the metal shell is mounted with rivets, not screws and nuts.

 

[jeff7tg]

Unless you want a loose dangling connector that will likely break after a few uses, then yes you want the shell firmly mounted to the plastic.

Most of the time when I've seen stuff like this where clearance would be an issue the metal shell is mounted with rivets, not screws and nuts.

I understand. So there is probably no solution with this specific converter and device, correct?

 

[ads-ee]

I understand. So there is probably no solution with this specific converter and device, correct?

Didn't say that. You could jury rig something. Like find screws with identical threading but a flathead torx or phillips type. Or get a rivet tool.