I've designed a custom board meant for high-powered model rocket telemetry & duel-deployment. (More info upon request)
To do this, I've soldered a ATMEGA2560 (yes, overkill, but I needed multiple hardware serials), with the plan on using the ICSP programming header I designed on the board to burn the Arduino bootloader, and then use the super-easy ftdi-compatible serial connector to program the board....
Problem is, I have thus far been completely unable to burn the bootloader. I've double-checked the wiring ten times, checked the labeling on my board, checked my board's schematic twice, and re-checked the chip's datasheet to make sure I didn't screw up the pinout, even held a jumper past my fancy reset circuitry that I largely copied from the official Uno schematic.
I've largely been using Nick Gammon's excellent "bootloader programmer" sketch Link on a Clone Arduino Mega. But I've tested the connections and sketch by using it to program the bootloader on a Arduino Pro Mini successfully with no hitch at all. :(
Attempting to enter ICSP programming mode..........................................
Failed to enter programming mode. Double-check wiring!
Here's a Board and (Schematic I can't post because I'[m new to the Arduino side of stack overflow... so replace the URL with schematic.png) of my board, and I'll upload a picture of my soldered board soon, but I'm actually quite confident of my soldering job...
Really just completely out of ideas, and very demoralized because the project I've been working on for months isn't working, and I have nothing specific to even point at...