Nice schematic, I can't wait to see the layout. I know PICAXE chips
(in fact, Microchip microcontrllers) are connected to serial interface
via 3 resistors, no MAX chip between... and everything is just fine.
Nice schematic, I can't wait to see the layout. I know PICAXE chips
(in fact, Microchip microcontrllers) are connected to serial interface
via 3 resistors, no MAX chip between... and everything is just fine.
> (unfortunately, the fact that jal don't have a math library is another
> obstacle regarding to "mass" adoption - the new comers remain with
> basic languages and advanced people go to C language).
I recall someone (you?) mentioned math functions once before. Is this
realy an issue? And which math functions would be required?
Although it might not be cheap (both in development and use), it
should be do-able.
Joep
2009/7/21 funlw65 <fun...@gmail.com>:
> In general, for newbies as I am, is easy to use math
> functions, even if is not efficient ... Is enough if chip is doing his
> job.
Untill it takes up such a part of your program memory that the rest of
your program does not fit any more...
> Anyway, it will be a complete compiler/language. And why not? Every
> language on the market have math functions.
It could be done. But it will require a major investment in
development time and it must be clear this time is better spent on
this then on other a bunch of whishes...
Joep
Nope. Look at it as an another example of PCBing a 4550 (you asked for
help :P and someone made something about : single sided and using
4550 ). But forget about if that don't help you.
On Jul 23, 8:09 pm, Sebastien Lelong <sebastien.lel...@gmail.com>
wrote:
> Nice ! Should we use this instead of building Jaluino ?
>
> Seb
>
In the current schematic the 5V and USB-5V are connected, this is not
according to spec,
see also the datasheet about USB self-powering.
Either way, use a
jumper selection for the
power supply or use some shottky diodes,
in addition it might be wise
to place a by-pass diode
across the 7805, since these devices don't like to be reversed
powered.
Why R1? I think
you can remove it, since the reset pin is held high
via R5/D2
Be sure to put a 100n bypass close to VSS/VDD pins of the PIC, I don't
know if C2 is the PIC bypass cap, if so I would
draw it closely to the PIC VSS/VDD pins
BTW, the 18f14k50 board is working fine
I noticed this topic and if you want I can help you with creating a
nice main board.
Maybe it’s an idea to make a nice double sided main board with a
18f4550 with all furthers
And extension possibility’s instead of a small single sided one which
will have its limitations
Of course people must buy this board but shall cost not more than
approx. €15 to €20
all extension board we can try to design as single side so home made
versions.
But you are right, it's something which is still on our list and we
will handle it in due time.
Joep
IMHO we should develop an own standard for Jaluino, off course using
the good ideas from other boards but not making exactly the same.
Jaluino is for Jal and developed by Jal (people).
I suggest to make the Jaluino mini pin compatible with a breadboard,
easy for testing.
If you all agree I can make all the schematics and pcb layouts.
I have placed the 18f2550 in the file section so we can discus it
before making the layout.
After that I can make the other schematics so we can disbud them
before making those layouts.
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.
I was thinking of making the pcb size of Jaliuno medium and maxi ½ a
eurocard (100x160) would be 100x80 but that is for later.
> Looks great. I can try to prototype few part of the schematic if you want.
please do, thanks
I know but when using USB, lines must be as short as possible so no
> - 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.
lose ends to a connector.
>> schematics inhttp://www.etc.ugal.ro/cchiculita/software/tinybldusage.htm section
> - 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
> "Options". Having the possibility to remotely reset the device is aAlbert made a bootloader for USB in this schematic the idea is using
> 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 ?
USB bootloader (if working)
or use ICSP.
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 :-).
see above
> 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 ?
No, serial delivers only a few mA of power this can give you lots of
> - 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 ?
trouble if you use standard RS232
Don’t see why not, but then all of your shields must be working with
>
> (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 ?
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.
The schematic i have from Arduino (duemilanove) only has one PB for
>
> > 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.
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.
chosen serial module ??? where can i see that module to have an idea
> 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).
I agree that Tiny is nice, but basically you'll have to offer the UART for
Host PC communication (same i true if you have a FTDI converter chip), if
you use native USB, you still have a UART available for JALuino shields.
>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).
It is possilbe if you add a MAX-232 on the board, and connect one of the
hanshake lines via a capacitor with the reset line
>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.
Yes this is possible, you can take the 5V from the USB connector, don't know
if you can configure the USB device current (100mAor 500mA), if you use
native USB, we can control it from the firmware and be able to draw 500 mA
max
>
> >
> > (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 ?
>
> Dont 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.
You dont need a LF device, the standard F devices will run at 3.3 volt as
well
>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.
And is available in DIP housing, so far more homebrew friendly than TSOP or
QFN devices,
You can buy pre-fabbed FTDI modules, but they are in the 10-30 Euro range,
but the problem with
these pre-fabbed units is that we dont know when they become obsolete, so
there is a great risk
that these units can not be bought next year..
I know that the 18f14k50 is not easily to obtain (except from Farnell,
Digikey & Microchip direct), but we might do setup a group buy for 18f14k50
devices, besides the PIC only a capacitor, 12 MHz crystal
and USB connector is required, so < 5 Euro on parts, to make a USB->RS-232
converter.
Albert
We can also ask Wouter to add this articles. In due time, he might
even add jalduino kits.
Joep
I agree that Tiny is nice, but basically you'll have to offer the UART for
>Mmhh... USB bootloader is far bigger than Tinybootloader. Saves space.
>Except for Jaluino Mini (18F14K50, breadboard pluggable, minimum hardware
parts), better use Tiny.
Host PC communication (same i true if you have a FTDI converter chip), if
you use native USB, you still have a UART available for JALuino shields.
Yes this is possible, you can take the 5V from the USB connector, don't know
>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.
if you can configure the USB device current (100mAor 500mA), if you use
native USB, we can control it from the firmware and be able to draw 500 mA
max
> Dont see why not, but then all of your shields must be working with
> 3.3VYou dont need a LF device, the standard F devices will run at 3.3 volt as
> 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.
well
>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.
And is available in DIP housing, so far more homebrew friendly than TSOP or
QFN devices,
You can buy pre-fabbed FTDI modules, but they are in the 10-30 Euro range,
but the problem with
these pre-fabbed units is that we dont know when they become obsolete, so
there is a great risk
that these units can not be bought next year..
I know that the 18f14k50 is not easily to obtain (except from Farnell,
Digikey & Microchip direct), but we might do setup a group buy for 18f14k50
devices, besides the PIC only a capacitor, 12 MHz crystal
and USB connector is required, so < 5 Euro on parts, to make a USB->RS-232
converter.
I have made a schematic for Jaluino maxi (18F4550) with hopefully
all the wishes you all have.
As ask by Seb, source can be obtained in3 ways
1 PSU through Jack (Jumper on JP1)
2 USB (Jumper in JP2)
3 Serial, powered by USB to serial TTL converter.
If you want to create a RS232 with a MAX232 you must
select for the source, Jack (JP1) or USB (JP2) and place
a jumper on JP4 to supply 5V to de serial connector.
Also ask by Seb is the reset option by RTS (J7).
The serial connector is pin compatible with the Bluetooth to serial
converter
The leds, PB and I2C are gone and must be made on a shield.
On a 2 layer pcb we can place them even with more bells and whistles
but better keep the homebrew one simple.
I maintained the reset on the power connector similar to Arduino if
you don’t mind.
better not used and have than needed and don’t have, if you now what I
mean.
The connectors are more routable friendly connected to the 18F4550 (I
hope) but
this I will notice as soon as I start with the pcb.
If you all agree I will use female array 2,54mm(0.1”) pitch connectors
for I/O,
male rectangle array 2,54mm pitch connector for serial and ICSP,
B-type USB connector and PCB power connector, see Farnell nr 1608726.
The schematic is placed in the file section.
Because shields must be of one size in depended if they are for Medium
maxi or bigger
I don’t expect a big difference in pcb size between medium and maxi.
Because real difference will be the number of I/O, I think nobody will
be interested
in Jaluino medium with a 18f2550.
Is it an idea to have Jaluino mini for 18f14K50, Jaluino Medium for
18F4550 and Jaluino Maxi
for something like the 18F87J50 (mentioned by Seb)?
> - option 3: I want to power the board with a serial module, provided itNo, don't place a jumper on JP3 AND JP4 at the same time, if you do so
> can. To do so, I put a jumper on JP3. JP1 and JP2 remain clear. It doesn't
> matter whether I put a jumper on JP4 or not, the result is the same.
>
> Is that right ?
your circuit and source is not protected
by fyse F1
Yes but than your pcb will become more complicated and it must be a
>
> Is it possible to replace JP1, JP2 and JP3 by a "tristate" trigger so
> there's no possibility for a user to put jumpers on JP1 *and* JP2 for
> instance (I could do this...). This would make the board more foolproof...
> if you know what I mean :)
home brew one
The moment you work with a pcb it is smart to know something about
your board or at
least read the description (we must make) very careful or else you can
blow up your board.
As the schematic already say, jumper on JP1 or JP2 or JP3, in the
manual (we need to make), we must tell them explicit not to place more
than 1.
[...]
> - All the serial modules I've used or built have their RTS connected to
> CTS. No flow control, quite common I think. Like in this article:http://www.lynxmotion.com/images/html/build125.htm. Now imagine I use such
> a module with RTS and CTS connected. I plug it to the board. Will this work
> ? Or should RTS and CTS remain unconnected from each other ? In that case,
> do I have to deal with flow control ? (hope not...)
Yes this will work and No you don’t need flow control, but like in
your link don’t connect the RTS end CTS from the serial module to the
serial connector of the Main Board else you can’t use RD4 and RD5 for
other purpose.
Those are not silly questions, just questions.
>
> Sounds like silly questions, but this whole reset thing is not clear for me
> :)
On software terms I know that I have sometime questions witch are
simple to you all but a question mark for me, still does not make the
questions ore me silly (do they?) :-).
[...]
I will make a drawing with dimensions for placing the connectors on a
>
> > The connectors are more routable friendly connected to the 18F4550 (I
> > hope) but
> > this I will notice as soon as I start with the pcb.
>
> > If you all agree I will use female array 2,54mm(0.1”) pitch connectors
> > for I/O,
> > male rectangle array 2,54mm pitch connector for serial and ICSP,
> > B-type USB connector and PCB power connector, see Farnell nr 1608726.
>
> About shield connectors, they'll have to be tall enough so all the
> components can fit under the shield. Like these ones, being used to build
> shields (they also have long pins so they can be plugged on the mainboard
> and expose shield connectors to other shields at exactly the same place):
shield board
So every body can make a shield board.
Dimensions will be in inches, which is common in pcb world
I already made a template for shields so I can easy make them
(connectors are already in place),
>
> http://www.sparkfun.com/commerce/product_info.php?products_id=9279http://www.sparkfun.com/commerce/product_info.php?products_id=9280
>Orcad capture 10.0
> > The schematic is placed in the file section.
>
> Thanks.
> Can you also provide the source files, loaded by your application. BTW, what
> application are you using to build this ?
I will download the file you need as soon as it is finished OK?
OK, see the file section Jaluino_maxi_pcb
Maybe I can make the pcb a little bit smaller (if you all insist) but
not much.
I expect that only 3 via’s (wire bridges) are acceptable ;-).