What is Next for the AL Priority?

[hussein]

@radargeek I can't view that thread but I love the details in your post! Thanks.

[orwellophile]

something about serial flash

yeah, there's a whopper. 8 megabyte of flash. and i would agree about chip functions. the usb capable chip is probably also doing the AesDecode() that enables everyone's firmware to be unique, it's also capable of secure aes booting, running code from ram (not that i've noticed any), and other fun things. there's an ISCP header on the left (i say that, knowing full well that PIC doesn't use ISCP) if you want to try bricking yours. there's also a green led on either side of the board that flashes nicely (as in, not too brightly).

still, i am left wondering, if there's only 256 + 128 = 384k of flash, why are our U0000000.bin files 460K?

i'm also wondering if Mark has released an open protocol for the expansion port, since I just found out my V1 has one (expansion port, and open protocol. also on a 6pin connector).

BTW, this board has some of the smallest surface mount resistors I have almost never seen.

[FJR1300]

Nope, you're way above my pay grade in component level pc board theory!

I take things apart all the time, definitely respect like minded tinkerers and modders.

[radargeek]

Chances are only the ALP engineers who developed the thing knows what the on-board headers are used for. Probably for the initial flash of the bootloader/serial/encryption keys and maybe for QA testing as well (test all the functions of the board before it's shipped). It may also be used for diagnostic purposes if a defective unit is sent back for repair/refurbishment. Even if it is an ICSP header, it's possible and probable that AL uses their own pinout rather than the standard one PIC programmers use. It could just be a diagnostic serial port to allow a diagnostic computer to talk to the processors on the board.

It's possible that the chips have bootloaders flashed on them even before they're installed on the board (I think Microchip offers this as a service for volume customers). They would still need serial #/encryption key info added if it's unique to each device. There's probably a computer at the factory programmed to do this, each time a board/CPU goes out it connects to the header, gives it a serial # and key, and prints the S/N stickers to put on the outside.

There's another header on the board, near the USB port. It's 6 pads inline but without holes. It looks much like a standard PIC ICSP header. And it even appears that pin 3 is ground and pin 6 is unused.