Gertboard


259 posts   Page 6 of 11   1 ... 3, 4, 5, 6, 7, 8, 9 ... 11
by meltwater » Mon Mar 05, 2012 9:29 am
Thank you for the updates!

I think your estimate of 100 boards will be well under (the 10k number is a drop in the ocean it seems), but obviously it is upfront cost anyway, so worth building up gradually (I guess cost/lead time will improve with higher numbers).  Hopefully by just selling the PCBs first, it should keep demand to a manageable level and since most people will be waiting on pre-orders it should give a little time to get things rolling though the shop.

As for site support, as soon as you are happy with the details and everything, we can build up suitable pages within the wiki for the Gertboard, no doubt the community can create some part lists for various suppliers too, so that side of it shouldn't be a big problem.  Just give us the details when they are ready.

I know nothing of the ATmega chip, hopefully someone who has used them might spot the issue.
______________
http://www.themagpi.com/
A Magazine for Raspberry Pi Users
Read Online or Download for Free.

My new book: goo.gl/dmVtsc

Meltwater's Pi Hardware - pihardware.com

Like the MagPi? @TheMagP1 @TheMagPiTeam
User avatar
Posts: 993
Joined: Tue Oct 18, 2011 11:38 am
by Gert van Loo » Mon Mar 05, 2012 9:36 am
I am hesitating between 500 or 1000 for the first batch. I have to negotiate wit the PCB company about the price. They may want me to 'fill' the board so there is minimal copper removal as that saves them in cost.
User avatar
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 2077
Joined: Tue Aug 02, 2011 7:27 am
by Gert van Loo » Mon Mar 05, 2012 9:36 am
I am hesitating between 500 or 1000 for the first batch. I have to negotiate wit the PCB company about the price. They may want me to 'fill' the board so there is minimal copper removal as that saves them in cost.
User avatar
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 2077
Joined: Tue Aug 02, 2011 7:27 am
by rurwin » Mon Mar 05, 2012 9:44 am
Gert said:

But as soon as I program the debug-wire fuse the system dies. I checked the reset/DBG pin and I can't see anything wrong with it.

DebugWIRE is almost as badly documented as the RaspPi GPU ;-) But I did see this in the data-sheet:

When the debugWIRE Enable (DWEN) Fuse is programmed and Lock bits are unprogrammed, the debugWIRE system within the target device is activated.


Correct 10K pull up to 3V3 in parallel with the diode. If I use 5k to pull the pin down it goes to half voltage so there really seems to be a 10K pull up only on that.


If you got half voltage, then your pull-up must be 5k, not 10k, which would be too low according to the data-sheet. Have you tried removing the resistor?

Pull-up resistors on the dW/(RESET) line must not be smaller than 10k?. The pull-up resistor is not required for debugWIRE functionality.

Since it is so badly documented, are you sure the diode is not causing the problem? Maybe it uses over-voltage.

User avatar
Forum Moderator
Forum Moderator
Posts: 2932
Joined: Mon Jan 09, 2012 3:16 pm
by Frank Buss » Mon Mar 05, 2012 9:49 am
Gert said:


I am hesitating between 500 or 1000 for the first batch. I have to negotiate wit the PCB company about the price. They may want me to 'fill' the board so there is minimal copper removal as that saves them in cost.


If you are using Eagle, you need just to add a polygon and set the signal name to GND for copper pouring, then execute "ratsnets". You can change "isolate" for setting the distance to other traces. Other CAD programs have similar features.

dfgdf
User avatar
Posts: 92
Joined: Fri Jan 06, 2012 4:39 pm
by aprice2704 » Mon Mar 05, 2012 10:22 am
Gert said:


I am hesitating between 500 or 1000 for the first batch. I have to negotiate wit the PCB company about the price. They may want me to 'fill' the board so there is minimal copper removal as that saves them in cost.


Greetings Gert! I am very much looking forward to the board being available.

I live in western Canada, so I can offer a North American perspective -- I suggest that you contact Limor Fried at Adafruit industries http://www.adafruit.com/ and talk to her about producing/distributing Gertboards (or RPis themselves for that matter). Sparkfun.com is another company that is well worth talking to, as are Evil Mad Scientist Labs http://www.evilmadscientist.com/.

I actually think that the RPi foundation made a mistake in not engaging any of these companies in the launch.

HTH

Cheers, Andy :)
Posts: 4
Joined: Mon Feb 20, 2012 9:02 am
by meltwater » Mon Mar 05, 2012 10:46 am
Gert said:


I am hesitating between 500 or 1000 for the first batch. I have to negotiate wit the PCB company about the price. They may want me to 'fill' the board so there is minimal copper removal as that saves them in cost.


Chances are if you make 1000, you'll be able to sell them easily (after-all, someone seems to be managing to sell a cig-packet on ebay as a RPi case).  Even, at that number, I don't fancy my chances at getting one.  But clearly, it costs money, so go with what you are comfortable with.  I'd be more than happy to pre-order if needs be, even if it ends up needing some manual mods if there is an issue with it etc, for prototyping that's not a big problem.

Is there much disadvantage to filling the board, or is it just that it needs another revision for that?

Hopefully you can throw in some sweeteners to them such as the example of how many RPi's have been pre-ordered, hence potential for re-ordering is very high and perhaps option for them to put their name/logo on the gertboard...for a healthy price reduction, and very very good advertising for them...

Hopefully once you've got started, getting them produced will be a small amount of hassle which the "new shop bod" can deal with directly anyway.  Or as mentioned, should be several places which would probably take it on otherwise.
______________
http://www.themagpi.com/
A Magazine for Raspberry Pi Users
Read Online or Download for Free.

My new book: goo.gl/dmVtsc

Meltwater's Pi Hardware - pihardware.com

Like the MagPi? @TheMagP1 @TheMagPiTeam
User avatar
Posts: 993
Joined: Tue Oct 18, 2011 11:38 am
by flyerblade » Tue Mar 06, 2012 11:09 am
This is a fantastic project, congratulations on getting so far. Really looking forward to purchasing one. I would imagine if it is possible to make a finished board that plugs straight onto the Pi, it would not take a lot of school orders to create a LOT of demand. Keep up the good work :-)
Posts: 15
Joined: Tue Mar 06, 2012 11:03 am
by ringz » Thu Mar 08, 2012 5:16 pm
Docteh said:


Debian squeeze has a package called arduino-core which brings in the necessary bits. avrdude avr-gcc and maybe some other stuffs.
http://mjo.tc/atelier/2009/02/.....o-cli.html
Boot loader might need to tweaked a bit to run at 12 mhz. I should go ask on the arduino forums. I know that they have 16mhz and 8mhz boards available.
I will have to check inTo jtagice mk ii.

Currently trying to find information on 12mhz, the first page of the atmega 8/168/328/etc datasheet mentions that you can do 0-10mhz with 2.7-5.5 volts But I guess thats just chip rating information, not directly specifically connected to "if you're running at 12mhz you need this many volts"

Looks like at 12mhz that is fast enough to do USB 1.1 in software. Project called V-USB for that. I'm not seeing anyone saying you shouldn't do 12mhz with 3.3v

Looks like the arduino bootloader uses the frequency to decide what baud rate to use.

JTAGOCE MKII: I read the docs for it and yes it looks like we're talking about the same thing.



If you are expecting users to put an Arduino boot loader on the 328 you would be better going with an 8MHz resonator that is standard for the Lilypad arduino which works at 8MHz & 3.3V. If you use 12Mhz the boot loader will have to be patched and also there will be work needed on the core files. The arduino timing system is only accurate at 8 or 16Mhz.

Martyn.
Posts: 22
Joined: Mon Mar 05, 2012 9:00 pm
by Gert van Loo » Thu Mar 08, 2012 5:21 pm
For the first board users have to assemble it themselves. So they can decide on 8 or 12MHz (or 16 if they want to risk it). I will try to remember to put a note about this in the assembly manual which I still have to write.
User avatar
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 2077
Joined: Tue Aug 02, 2011 7:27 am
by SN » Thu Mar 08, 2012 5:39 pm
Just read enough of this thread to say, if the price point is OK (<£100) then I'm also registering my interest (in a more reliable and permanent way than at RS ;-) ) in a Gert  Board
Steve N – binatone mk4->intellivision->zx81->spectrum->cbm64->cpc6128->520stfm->pc->raspi ?
User avatar
Posts: 1008
Joined: Mon Feb 13, 2012 8:06 pm
Location: Romiley, UK
by Jim Manley » Sat Mar 10, 2012 7:14 am
The board is just fantastic, that is really what I think.  Oh, by the way, which one's Pink?

GertBoard_count++; // ;)

This really is a boffo job, Gert.  If we can drag enough of us old hardware-enabled farts at least to local RasPi SIG/UG meet-'n-greets, we can definitely generate a ton of interest in the kids who are Geeks bearing The Gift.  We won't be able to count on more than a handful of teachers to show any inkling of what this is for, much less how to teach kids what to do with it.  I kind of like the ability to populate the board with as much or as little as you want initially, and adding components for additional capabilities as needed/desired.  If you don't care about D/A or A/D or an AVR, etc., just don't install them (I haven't looked closely to see what the dependencies are - you might want to provide a graphic in the assembly/user manual that shows groups of dependent parts outlined together superimposed over the board photos).

Looks like these could arrive right around when my R-Pi may be magically appearing (assuming the correct amount of fairy dust has been molded into the USB sockets, now that the Ethernet sockets are being fixed ;) ).  Christmas in April ... looks like I need to drag out the desktop pine tree and string the LEDs and tinsel again so I'll have somewhere to unwrap all of the packages that are currently waltzing with sugar plums in my head ... :)
The best things in life aren't things ... but, a Pi comes pretty darned close! :D
"Education is not the filling of a pail, but the lighting of a fire." -- W.B. Yeats
In theory, theory & practice are the same - in practice, they aren't!!!
User avatar
Posts: 1357
Joined: Thu Feb 23, 2012 8:41 pm
Location: SillyCon Valley, California, USA
by tofflock » Mon Mar 12, 2012 12:59 pm
Gert said:


These are bare PCBs only thus much simpler to produce or sell. I talked to Liz and they will probably go trough the raspberrypi.com website.



In case you're counting expressions of interest, I'd like a couple of boards too please.

Well done too, on a very professional looking board done in that very scarce resource called "spare time".
Posts: 1
Joined: Mon Mar 05, 2012 11:53 am
by rdepew » Tue Mar 13, 2012 5:41 pm
Andrew Price said:





I live in western Canada, so I can offer a North American perspective -- I suggest that you contact Limor Fried at Adafruit industries http://www.adafruit.com/ and talk to her about producing/distributing Gertboards (or RPis themselves for that matter). Sparkfun.com is another company that is well worth talking to, as are Evil Mad Scientist Labs http://www.evilmadscientist.com/.

I actually think that the RPi foundation made a mistake in not engaging any of these companies in the launch.


Hmm. I wonder if it's too late? Either or both of these would be great partners for RasPi.
Posts: 3
Joined: Thu Feb 09, 2012 6:38 am
by Nobody » Tue Mar 13, 2012 8:55 pm
Your board is looking great Gert.

I have a couple of questions though:

What happened to your beta-board? (sorry if I missed something)

What's the size of your current prototypes?

Did you use a rather small AtMega (instead of a 40/44 pin model) because of the size? (I was thinking of using the Atmel as a port expander)

May I ask how much your prototypes cost and were you get them from? I'm interested in this because I'm wondering if it would be worth the effort to redesign it using some smd components (especially a TQFP44 Atmel) and ordering it for about 20 Eurocents per cm².

And thank you for your efforts.
Posts: 16
Joined: Tue Nov 01, 2011 8:07 pm
by Jim Manley » Wed Mar 14, 2012 12:35 am
I hope we can safely assume the GertBoards aren't going to be distributed by RS or Farnell?  ;)

Not that it would matter, since we're much more likely to receive GertBoards long before our R-Pi boards no matter who manufactures and distributes them, given the difference in demand between them  ):
The best things in life aren't things ... but, a Pi comes pretty darned close! :D
"Education is not the filling of a pail, but the lighting of a fire." -- W.B. Yeats
In theory, theory & practice are the same - in practice, they aren't!!!
User avatar
Posts: 1357
Joined: Thu Feb 23, 2012 8:41 pm
Location: SillyCon Valley, California, USA
by hastklass » Sat Mar 17, 2012 8:58 am
As a teacher with nearly 30 years experience of teaching computer control I see this as a ‘killer app’ for the R-Pi – particularly with contracting budgets.  The currently outlay for a control workstation is about £300 for the PC, £150 for the interface and software to run it - £450/workstation.

I have no price for the Gertboard but am guessing about £25.  Second hand keyboards, mice and even monitors can be picked up for next to nothing.  I am setting up a R-Pi lab at my school using keyboards, monitors and mice from old redundant computers – they would have gone for recycling so cost us nothing - £47/workstation (excluding software).

As it stands the Gertboard may not be attractive to all DT teachers.  They are conservative animals and current workloads often inhibit change particularly when it comes to schemes of work, lesson plans, pupil resources and software skills.  Add to that the fact that many DT Departments are already stocked with components to use with the interfaces typically employed for school project work.

For example at my school (St John’sCollegeSchool,Cambridge), for computer control we use Flowol v3 software (as do many schools).  If this could be made to run on the R-Pi that would be fantastic – children and teachers already know how to use it.  I guess it would be relatively simple to write something similar – if open source then all the better - but Flowol would be the model to follow.

For many projects the Gertboard – as it stands – will work fine; however, it cannot do everything that we are used to from our control interfaces.  If Gert has the time and is considering future developments I would highly recommend that he takes a look at some of the most popular interfaces used in schools.   A typical spec for KS 3 and KS 4 project work would be:

• 8 Digital outputs
• 4 Motor outputs
• 8 Digital inputs
• 4 Analogue inputs
• An external power supply providing 6 Volts at up to 2 Amps

(see Co Co, Data Harvest and Deltronics et al)
Raspberry Pi Certified Educator
Raspberry Pi Certified Educator
Posts: 26
Joined: Mon Dec 12, 2011 11:20 am
Location: Cambridge
by Gert van Loo » Sun Mar 18, 2012 8:08 pm
It would be possible to do the list above but it would not be easy as the Pi has only 17 GPIO's. So you have to add e.g. an SPI to I/O expander.

The price is no yet know but I think that your £25 is too low. Such a price would be feasible if it was made in large volumes which is not planned yet.
User avatar
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 2077
Joined: Tue Aug 02, 2011 7:27 am
by Gert van Loo » Sun Mar 18, 2012 9:46 pm
New video on Youtube: (Post edit: when I talk about boards I mean Printed  Circuit Boards. Not fully assembled boards)

feature=youtu.be
User avatar
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 2077
Joined: Tue Aug 02, 2011 7:27 am
by fpaliuc » Mon Mar 19, 2012 8:45 am
Hello Gert!

First of all I want to say you did a great job. I'd be interrested too in one of your boards.

I'm curious if you could post somewhere the whole code you've used in the demo video on the YouTube (I'm not a programmer but I'd like to see how you controlled it all).

Thanks
Posts: 6
Joined: Tue Jan 10, 2012 6:21 am
by rurwin » Mon Mar 19, 2012 8:58 am
Congratulations Gert. Very Nice.
User avatar
Forum Moderator
Forum Moderator
Posts: 2932
Joined: Mon Jan 09, 2012 3:16 pm
by the_summer » Mon Mar 19, 2012 10:00 am
Looks great Gert. I'm really looking forward to it. You finally got me to register ;-)

I have a question about the avr:
Will it be possible to access/control the ADC and the PWM  with the avr microcontroller or only via the RPi?

And does the board have a two wire interface? (Thats probably mentioned before but not on the last few pages of this thread)

Best regards,

Jan
Posts: 8
Joined: Mon Mar 19, 2012 9:49 am
by RaTTuS » Mon Mar 19, 2012 10:07 am
Excellent Gert - that makes me want to getone of those even more now ;-p
http://www.catb.org/esr/faqs/smart-questions.html <- ask smart Questions
"That's not right, the badgers have moved the goalposts."
1QC43qbL5FySu2Pi51vGqKqxy3UiJgukSX - Prosliver FTW
User avatar
Posts: 5315
Joined: Tue Nov 29, 2011 11:12 am
Location: North West UK
by Gert van Loo » Mon Mar 19, 2012 10:12 am
the_summer said:


Looks great Gert. I"m really looking forward to it. You finally got me to register ;-)

I have a question about the avr:
Will it be possible to access/control the ADC and the PWM  with the avr microcontroller or only via the RPi?

And does the board have a two wire interface? (Thats probably mentioned before but not on the last few pages of this thread)

Best regards,

Jan


Yes, the SPI interface is connected to the Raspi using jumpers. So you take the Raspi SPI jumpers out and connect the SPI interface of the ADC/DAC to the AVR. Same for the motor controller.

The ADC and DAC chip share the SPI interface pins so you can not connect e.g. ADC to the Raspi and the DCA to the AVR.

You can also connect the AVR SPI to the Raspi SPI if you want. One of the two has to be in slave mode then.

Sorry no, there is no 2-wire interface.  Neither is there an I2C interface.
User avatar
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 2077
Joined: Tue Aug 02, 2011 7:27 am
by the_summer » Mon Mar 19, 2012 11:03 am
Gert said:


Sorry no, there is no 2-wire interface.  Neither is there an I2C interface.


Is it possible to reprogram the pins of maybe the DAC on the avr to work as a TWI/I2C?
The reason why I ask is, that we have quite some sensors (e.g. magnetometer, gyroycope) which work via TWI.
Posts: 8
Joined: Mon Mar 19, 2012 9:49 am