add USB IO project [jaluino, one more time :)]
Sebastien Lelong
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)
- USB port
- ISCP
- I²C
- few LEDs for status (RX, TX, I²C, 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)
Cheers,
Seb
a.faber
Would like to write a small blog on jallib to explain how to use the USB-IO
board, any idea how I can create such a new blog?
Albert
a.faber
>Do you guys have any schematics I could get inspired from ?
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
Sebastien Lelong
No need to create a new blog you just have to create a new post(or
more !) on jalliblog. I'll create an account for you asap.
This is a very good idea, we definitively need to invest more time on
documentation, tutorial & howtos with pictures, etc...
Cheers,
Seb
Le 27 juin 09 à 22:33, "a.faber" <a.f...@chello.nl> a écrit :
Sebastien Lelong
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 ?
For 18F4550 ?
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.
That's definitively a good idea ! The only problem I can see is 18f14k50 is quite hard to find. Only from Microchip or Farnell for what I've searched, with incredibly high shipping rates...
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.
Maybe a "simple" Tiny bootloader would be better...
Cheers,
--
Sébastien Lelong
http://www.sirloon.net
http://sirbot.org