Arduino Duemilanove hardware uart problem

Recently i have been working with controlling stepper motor via a motor driver using txrx on arduino. Now, i suspect that when i powered on the arduino, and im rotating the stepper motor shaft which itself generates the current, runs backward into the pin 0 and 1 (tx , rx) and damaged the pin. Since then, when i do Serial.println to the motor driver, it doesnt respond to the command anymore. I have tried several things like:

  1. the “test” button on the stepper motor driver to ensure that the stepper motor is working fine. And yes, the stepper motor is fine.
  2. To check the tx rx port on the motor driver by plugging other hardware and running it by GUI provided. And its working fine. The txrx on the motor driver has no issue at all.
  3. To test run the stepper motor via softwareUART alternatives on pin 2 and 3. And yes, it works for software UART to command the stepper motor driver.

Now then, can i conclude that i have disabling the tx rx pins for its capacity to send serial data? However, if i were to use pin 0 and 1 as I/O, i have tested with LED and it’s working fine. Any alternatives to check whether my hardware UART is running fine? Or is there anyway i can just reboot the whole arduino? Please help! I’m a newbie.


Can you still upload new code to your Arduino?

If yes, the uart is fine (true for non-mega boards at least).

yes, i can still upload the code to arduino, just that the motor driver doesn't listen to the transmitted data from arduino anymore. But the motor driver can listen to another hardware. Ok, then i'll just stick to software serial until i found another way. Thanks @madworm!

Strange. I'm sure you've checked the serial speed settings already.

I have set it to serial.begin(9600) to interface with the motor driver. It works well for 1 month and suddenly when i suspect it maybe the reverse current from the stepper driver that damages it. But still coding uploadable.