Arduino Uno not uploading

Hello,

While working on a self-balancing robot project using an Arduino UNO, it suddenly stopped uploading. We're powering it along with an l298n motor driver using 8 AA batteries. In order to turn it the robot off, we disconnected the VIN pin powering the Arduino and left it hanging. Before it stopped uploading, the high voltage pin touched the ICSP pins accidentally and caused the Arduino to turn on. It was brief for a second at most.

Now, this error appears when trying to upload any code.

Sketch uses 10708 bytes (33%) of program storage space. Maximum is 32256 bytes.
Global variables use 735 bytes (35%) of dynamic memory, leaving 1313 bytes for local variables. Maximum is 2048 bytes.
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0xc8
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0xc8
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0xc8
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0xc8
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0xc8
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0xc8
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 7 of 10: not in sync: resp=0xc8
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 8 of 10: not in sync: resp=0xc8
avrdude: stk500_recv(): programmer is not responding
Problem uploading to board. See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.
avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0xc8
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0xc8

The on LED and the built-in LED are working fine, but the TX is no longer turning on and the RX flashes momentarily with every trial.

We tried a different board, and it was uploading normally, but now both dc motors stopped working. We suspect something happened to the motor driver, but we are unsure.

Could such an accidental touch to those pins cause such damage?

Considering the fact that the maximum output current rating for any pin is 40 ma, IMHO I’d say yes, it is quite possible to cause damage. Not knowing what pin you hit makes it hard to say where the damage would be though. Attached is a schematic of the Uno

I think it touched one of the outer ICSP pins, then the wire slid down and touched the A5 analog in from the bottom where it soldered.

Would such damage be unfixable? it would be a shame if it were that easy to accidentally destroy a board. :frowning:

Thank you though.

If you look at the schematic the pins on the "outside" of the header are 2,4, and 6 with assignments of +5v, MOSI, and Ground, respectivly. If it shorted to the +5v pin that means you've placed a 12V (8 batteries X 1.5V) on the 5V lead that feeds the IC's. If it hit the MOSI (aka) D11, there was probably a considerable amount of current draw given the difference of potential. From the Spec sheet we see:
26.1 Absolute Maximum Ratings*
.
NOTICE: Stresses beyond those listed under “Absolute
Maximum Ratings” may cause permanent damage to the device.

Voltage on any Pin except RESET
with respect to Ground ................................-0.5V to VCC+0.5V
Voltage on RESET with respect to Ground......-0.5V to +13.0V
Maximum Operating Voltage ............................................ 6.0V
DC Current per I/O Pin ............................................... 40.0 mA
DC Current VCC and GND Pins................................ 200.0 mA

I would say that the board is almost certainly trashed. Putting 12v (from batteries especially, as they have almost no current limiting) would indeed do some serious damage. It could definitely have damaged the motor shield as well, as some of the pins on the L298N can't be exposed to 12v without harm.