Schematics and PCB layout are checked in to SVN
>Already talked about this, but we could also build a nice board with
>18[L]F4550 (fa[s]t enough to handle many things), flexible enough so we can
>add other module (ala arduino shields). It could have:
>
> - jack to power the board, or could be powered via USB port
> - serial connector (option: USB connector connected to UART via a FTDI
>module, to save space)
If space is an issue, I would suggest to use 18f14k50 instead as a
USB<->RS-232 convert (just checked in the code for the 18f14k50 board),
since the FTDI chips can be difficult to solder for the average home brewer,
while the 18f14k50 is cheaper (~2 euro), is available in DIP-20 housing,
and it can do some specfic board management stuff, since it is far more
programmable than a FTDI chip and it has a wide voltage operating range
(1.8 -> 5.5v), and of course it is a Microchip/Jal(lib) solution.
> - USB port
> - ISCP
> - IC
> - few LEDs for status (RX, TX, IC, USB ?)
> - each pin could go to inline connectors (see picture, top and bottom),
> so
> other boards could be plugged on it (see pictures)
> - power sections: 5V, 9V (original power), ideally 3.3V
> - bootloader activated via serial (no need to manually reset the board)
USB bootloader code is available (see USB-IO board project), however, it is
much larger than for example the tiny-bootloader and it (currently) has some
resistrictions on the low priorty interrupts and forcing a PIC reset (need
some compiler changes, Kyle is working on the issues), but the big bonus is
that it is written in JAL :)
so expect that the isses are resolved in the next compiler update.
Albert
Schematics and PCB layout are checked in to SVN
>Very nice ! I've just bought two 18LF4550, I'm about to dive into USB soon.
>Do you guys have any schematics I could get inspired from ?
If space is an issue, I would suggest to use 18f14k50 instead as a
> - serial connector (option: USB connector connected to UART via a FTDI
>module, to save space)
USB<->RS-232 convert (just checked in the code for the 18f14k50 board),
since the FTDI chips can be difficult to solder for the average home brewer,
while the 18f14k50 is cheaper (~2 euro), is available in DIP-20 housing,
and it can do some specfic board management stuff, since it is far more
programmable than a FTDI chip and it has a wide voltage operating range
(1.8 -> 5.5v), and of course it is a Microchip/Jal(lib) solution.
USB bootloader code is available (see USB-IO board project), however, it is
> - bootloader activated via serial (no need to manually reset the board)
much larger than for example the tiny-bootloader and it (currently) has some
resistrictions on the low priorty interrupts and forcing a PIC reset (need
some compiler changes, Kyle is working on the issues), but the big bonus is
that it is written in JAL :)
so expect that the isses are resolved in the next compiler update.