Fried my Arduino

tnegun

So I fried my Arduino the on and L13 LEDs come on but it's not detected by my laptop and shows no sign it's trying to load a sketch. Can anyone tell me how I did it?

I was following this guide https://blog.udemy.com/arduino-voltmeter/ to try read the voltage of the batteries on my solar array. I didn't have a 100k or 10k resistor so I used a 4.7k and 470 in their place and updated the sketch. I measured the voltage with a multimeter and 12.9v was being supplied and I was getting about 1.1 where R1 & R2 meet. So well within the 5v max for Arduino. I connected the Arduino as per the circuit on udemy and it powered up through the analogue pins I then connected to a Raspberry Pi(via the USB I was planning to read the voltage on it) and it powered up too so I disconnected the Arduino but the damage was done.

I'm guessing it drew so much current through the analog pins on the Arduino it fried something?

ShRT

Were you trying to monitor the voltage on the pi through A1 and GND?

tnegun

ShRT wrote: »

Were you trying to monitor the voltage on the pi through A1 and GND?

No that was connected to the battery. I was hoping to read the battery voltage via the serial out on the Arduino from the Pi.

ShRT

I'm not quite following your text above. Which pins did you have connected on the arduino and to what?

tnegun

ShRT wrote: »

I'm not quite following your text above. Which pins did you have connected on the arduino and to what?

I'm on the phone so can't link directly but if you look at the udemy link in my op it has a building the circuit section and diagram and I copied the physical connections exactly but used different resistors. The Raspberry Pi was connected to the Arduino's USB port.

ShRT

Sounds like you blew the ftdi chip - it provides the serial to usb connection to allow for programming of the actual atmega chip that is the brains of the arduino.

Its not the end of the world. You can still use the arduino but you now need to program it in a different way.
Do you have a second arduino? If so you can pop the atmega 328p out of the broken one and swap it over to the good one. Then upload the program as normal and swap the chip back to the broken one when finished. Not ideal for testing but if you were going tp leave it in place in a project, its not so bad.

You can also use a second arduino to do icsp upload of code.
http://www.instructables.com/id/How-to-program-a-AVR-arduino-with-another-arduin/


You can also program it over ttl
https://www.sparkfun.com/products/9716

tnegun

Its a clone so the chip is soldered . I'm anxious to figure out how I damaged it though was it using smaller resistors that allowed too much current flow back through the Arduino to the Pi?

ShRT

the second two options will work even when the chip is in place on the board. The ICSP is probably the easiest to go with.

ozmo

tnegun wrote: »

Its a clone so the chip is soldered . I'm anxious to figure out how I damaged it though was it using smaller resistors that allowed too much current flow back through the Arduino to the Pi?

..before giving up on it

I had one messed up like this - and it was a software issue - too much ram allocated in the program I believe caused it.

I fixed it and was able to brick the arduino again by just by reloading my program again - issue caused the bootloader to fail to run and so the device didn't show up in the os.

To fix - I had to reflash the bootloader and upload something simple like blink using an ISP flasher and it was fine again.

Jimllfixit

ozmo wrote: »

..before giving up on it

I had one messed up like this - and it was a software issue - too much ram allocated in the program I believe caused it.

I fixed it and was able to brick the arduino again by just by reloading my program again - issue caused the bootloader to fail to run and so the device didn't show up in the os.

To fix - I had to reflash the bootloader and upload something simple like blink using an ISP flasher and it was fine again.

Good idea, do this first.