Hiho,
First of all i want to say this is a really cool project and a fantastic community!
I am a complete noob in programming microcontrollers, but i think im learning fast (sometimes it hurts thou)
My plans with Arduino go towards interactive art projects.
I got an Mega ADK and i am still working my way through basic examples in controlling/combining basic setups (mainly sensors ans motors)
One of my first steps was gathering parts from all sorts of devices (broken scanners printers etc.) so i have a few stepper motors that i want to include in my first mobile arts project.
Thatfore i have bought a EasyDriver stepper driver, wich is working well.
Since one of my steppers is labeled 24v i didnt get it to work to my satisfaction with 5v - 12v but i also hacked an old ATX powersupply so i can use it for my lab, thatone includes a negative 12v supply, so i thought hey -12v to ground +12v to my EasyDriver external vin and i get my 24v! (see picture) just i didnt consider that EasyDriver connect its grounds to my arduinos ground to be common
So basically what happened i supplied negative load (-12v) to my arduino and since that its "toasted"
Symptoms when connecting usb are:
- Power LED is permanently on
- onboard (pin 13) LED is permanently on
- arduino doesnt get recognised by my systems (i tried several machines Linux, MAC, Windows and several usb cables) "unable to enumerate usb device" a little research shows that the device doesnt supply vendor id or device id, its all zeros, power from usb works thou
I checked the boards pins with my multimeter and all seems fine (3.3v, 5v, voltage regulator, etc.)
After searching the forum and other ressources i come to the conclusion that either the ATmega2560 Microprocessor or the ATmega16U2 is toasted (or both)
so what i did is i ordered a new Mega ADK (i will need a second one anyway for Production) and i found "Arduino-COMBINED-dfu-usbserial-atmega16u2-MegaADK-Rev3.hex" in arduinos github, is it possible to reflash both ATmega2560 Microprocessor and ATmega16U2 using that file and another Mega as ISP or do i need an external programmer to do that?
Is there any chance that this wil help at all? I want to atleast be able to program the toasted Mega using serial if the ATmega16U2 is fried.
Thanks for all suggestions!