> > > > Looks great. I can try to prototype few part of the schematic if you > want. > > > please do, thanks
I'll do my best but it'll take time. > > > - I think RC4 and RC5 should be part of connector, if no USB is used, > we > > can still use the use pin (this is what I called "exported pins": pins > being > > part of a connector and available to shields. > > I know but when using USB, lines must be as short as possible so no > lose ends to a connector. But if not using USB, you'll loose two precious pins... Is it possible to connect RC4/RC5 to USB connector (as short as possible) and yet having them going to the connector ? > > > > > - I've never tested this but if we use Tinybootloader (I'd like to), > it's > > able to reset the PIC by setting RTS. Some hardware is required, see > > schematics > > inhttp://www.etc.ugal.ro/cchiculita/software/tinybldusage.htmsection > > "Options". Having the possibility to remotely reset the device is a > > must IMHO. I'd need to prototype and test this on a breadboard (but I'm > > having troubles making tiny working). I've also seen you've put a reset > pin > > on Power connector. What would be the usage ? > > Albert made a bootloader for USB in this schematic the idea is using > USB bootloader (if working) > or use ICSP. Mmhh... USB bootloader is far bigger than Tinybootloader. Saves space. Except for Jaluino Mini (18F14K50, breadboard pluggable, minimum hardware parts), better use Tiny. > > If you want to use RS232 you need to make a shield and there you can > use the RESET line (in the > power connector ) for reseting the system with in your case RST :-). Not necessarily if using hardware for Tiny apparently. Resetting PIC without manual operation should be available without any shields required IMO (basic and very useful feature). > > > hardware for reset tiny (instead of reset via power connector ?) > > - partially related to previous bullet: all the serial module I have > have > > RTC and CTS pins (bluetooth-serial converter and USB-serial FTDI based > > converter). Should we add this pins to serial connector ? > > see above But should we add a RTS and CTS to serial connectors in anyway ? So available to shields ? > > > > - finally, my USB-to-serial module also is able to provide power. This > > would give a third option to power supply: > > > > 1. power is taken from a wallmart power supply (jack) > > 2. power is taken from USB connector (the one we have in our > schematics) > > 3. power is taken from serial module, when available (for instance, > > available when using USB-to-serial connector) > > > > Is it possible to add this 3rd option ? > > No, serial delivers only a few mA of power this can give you lots of > trouble if you use standard RS232 Sure, but I'm not talking about taking power from a standard RS232, but from a USB-to-serial converter. Actually power is taken from USB. (see this module: http://cgi.ebay.fr/FTDI-Convertisseur-USB-a-UART-TTL-pour-ATMEL-AVR-PIC_W0QQitemZ310158443602QQcmdZViewItemQQptZFR_YO_MaisonJardin_Bricolage_ElectroniqueComposants?hash=item4836e24452&_trksid=p3286.c0.m14 ) > > > > > (last thought: Using PIC LF versions, we can make them run at lower > voltages > > than 5V. My USB-to-serial converter also is able to provide 5V or 3.3V > (and > > many of these provide the kind of things). Will this work with 3.3V for > > instance ? > > Don’t see why not, but then all of your shields must be working with > 3.3V > or you also need to add 5V and than every body needs to be careful not > to blow up the anything because of mixed up power. OK > > > > > > > As you can see I also added a pushbutton and led so without a shield > > > you can already work with usb, serial,i2c and do the, “blink a led” > > > tests and have a input. > > > > Yes, as in original Arduino, good idea to check the board. > > The schematic i have from Arduino (duemilanove) only has one PB for > reset so for there users there is no input option, but it does have a > led your right. > I was also thinking about placing a potentiometer for analog options > but did not because of probably layout problems (see Alberts blog on > 18f14K50 where we did use a potentiometer). > But off course as I set before “use the good things from other > Boards” :-) so were I can I will. Sure, but the goal isn't to build a development board, but a board that could be used in many projects. The idea is to expose as many pins as possible, without adding any "features" or parts (except maybe a LED. I now have doubts about a push button to test input...). Just like Arduino. On the other side, we could have a development *shield*, with all the stuff to play with, like pots, push buttons, more LEDs, etc... Just plug it on the board, and play with it (would also be a nice educational shield to create tutorials). Let's keep the main board as flexible, as versatile as possible. > > > > In my first attempt to make a PCB, I've reserved a space so the chosen > > serial module can be plugged (see bottom left part). > > chosen serial module ??? where can i see that module to have an idea I do have these ones (but the idea is everyone could his own. Joep uses other kind of serial modules IIRC): * http://cgi.ebay.fr/FTDI-Convertisseur-USB-a-UART-TTL-pour-ATMEL-AVR-PIC_W0QQitemZ310158443602QQcmdZViewItemQQptZFR_YO_MaisonJardin_Bricolage_ElectroniqueComposants?hash=item4836e24452&_trksid=p3286.c0.m14 (There are many FTDI-based USB-to-serial converters out there, they work all the same... and power could be taken from this kind of module, making the board very easy to use) * http://www.sparkfun.com/commerce/product_info.php?products_id=582 Albert also suggested to build a serial module based on a 18F14K50, just to make a conversion between USB and serial. This option would be cheaper than a FTDI-based solution. Finally, a real DB9 serial module with MAX232 could also be used. Cheers, Seb --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "jallib" group. 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