GorF, MIDI sysex and PCB update

Well, finally after two days of coding, head scratching and some help from Marc (cheers Marc, it’s much appreciated) I’ve now got a command line tool for my mac that takes an Atmel .ROM file and converts it into a file suitable for transmission over midi as a sysex file.

I’ll almost certainly post the code for this converter as well, so people who don’t have AVR programmers and who don’t want to keep swapping out the micro from the board (as it doesn’t have an ISP interface) can compile their code, run it through this, then update it via MIDI.

What I need to do now is write the bootloader for the micro that will detect a button help on power up and put it into update mode and ready to receive MIDI and update the firmware. So that is this coming week’s work whilst I’m waiting for the prototype PCB, which is due to be dispatched on the 13th of this month and should be with me a day or two afterwards.

On the subject of the PCB, I’ve noticed that the caps I use for the buttons slightly overhang the edge of the buttons. This means that the PCB I’ve made may have a problem with the buttons being too close to have the caps on. So there may well be a second prototype to come yet, I’ve had a thought about a way around this as an interim so I can crack on with testing and code development.

Someone also asked if adding an LCD in place of the 7 segment displays would be possible. and in theory yes it could be done, though you’d need to use the 4bit LCD interface mode rather than 8 bit, and you would have to not install the 7 segment displays.

So, if the button spacing is wrong and I need to do another revision of the board, I’ll try and include a 16way IDC header for an LCD in case people want to use that in preference. If I do, I’ll also mod the code so at compile time you can choose LCD or 7 Segment, though I personally prefer the 7 segment displays as they feel very “retro”.

One important thing, the panel design as shown in my previous posting here, has really gone out the window as the pot spacing on this board is too close and the 7 segment displays would be in the wrong place. There’s also two extra buttons on this PCB (planned for use for saving and loading when I have the serial EEPROM working). I had hoped to use a larger PCB and offer landscape or portrait mounting of the displays, but I don’t have the luxury of the bigger PCB, I’m not sure how this could now be fitted into a MOTM/Synth.com/Oakley sized module. I guess we’ll know more once the PCB arrives.

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