I am getting the error "avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x06". Is that a breadboard/protoboard shield? If so, I guess it has minimal onboard circuitry and should be safe to use on a Udoo (when placed on the correct pins)- just be careful that whatever circuit you build on it is 3.3V-safe.I am trying to upload a sketch onto an Arduino Mega using an Arduino Mega as the programmer. With the shield correctly aligned, that may no longer be a problem, unless the Udoo's power jack and/or heatsink get in its way. That ICSP header I mentioned is the 2x3 one on the righthand side of your photo, beyond the resistor and LED, which seems to be hitting another header. The same goes for the opposite side, where you'll use 6 pins of the two 8-pin headers over there, spanning from RESET to Analog-In #5 - this area is where the power voltages connect, so it's especially important to get the alignment right. Most new Due pins are on that side, next to the long double-wide header, but a couple of extra ones were also added on the opposite side (SCL1, SDA1 next to AREF), so if I'm counting right, your shield will only use 8-pins of that 10-pin header, its final pin matching up with the AREF position. 14 and beyond are newly-added Due pins that didn't exist on smaller Arduinos, and which your shield therefore isn't designed to mate with. Note the discontinuous numbering, where pins 14 and higher begin next to pin zero. The Due pins are more clearly labeled than on a Udoo, with no huge heatsink in the way, but their arrangement is identical. Please take a look at these photos, especially the pin labels, and note exactly which pins are in common between the Duemilanove and Due: It needs to be moved to the right by about 8 pin positions, or one full header, which might be why you're seeing the alignment problem.
![arduino mega pinout icsp arduino mega pinout icsp](https://lehelmatyus.com/wp-content/uploads/2016/12/arduino-nano-pins.png)
![arduino mega pinout icsp arduino mega pinout icsp](https://elosciloscopio.com/wp-content/uploads/2021/03/Mega-tutorial-de-Arduino-Pinout.png)
I missed this before, but I think you have your shield over the wrong set of pins. The fit problem might have helped protect you from this. putting it on the opposite side would reverse even/odd pins.īefore resorting to that, please double check to make sure your shield is even compatible with a Due in the first place- if it has components blocking the Due's extra pin headers, there's a good chance it won't play well with 3.3V signal levels either, and might damage your Udoo by putting 5V on the I/O pins. If that's needed to program an on-shield microcontroller, maybe it could be reattached to the end of a ribbon cable? Just be careful to get all the pins correct- e.g. Unless you have a spacer shield to put in between, clipping off or desoldering the ICSP block from your shield may be the only solution. You'd have the same trouble trying to plug it into a Due (rather than Duemilanove), or Arduino MEGA, which both have the same extra header for PWM signals that gets in the way of this particular shield. The fit problem with your shield is its extra "ICSP" header, which doesn't match up with any standard Arduino pinout- its designers just assumed that space underneath would be vacant.
![arduino mega pinout icsp arduino mega pinout icsp](https://1.bp.blogspot.com/-J1hXXB__r84/YMXjTkgJnJI/AAAAAAAAAIw/IxcXe-98fGkui4QRYdY9FUCpShP1h9qjACLcBGAsYHQ/s407/arduino%2Batmega%2B2560.jpg)
I think that first photo is actually an Arduino Duemilanove (8-bit AVR based, 5V), which despite the name is much more like an Uno than a Due (32-bit ARM, 3.3V, many more pin headers).