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by Frank Buss
Wed May 09, 2012 3:00 am
Forum: HATs and other add-ons
Topic: simple 16 signal GPIO I2C board
Replies: 31
Views: 18680

Re: simple 16 signal GPIO I2C board

<r>Got a Raspberry Pi (couldn't wait, so I bought it from eBay) and it works with my IO Expander. Just attach 4 jumper wires and you have 16 protected GPIOs:<br/> <br/> <br/> <br/> Discussion about my modification of the Linux driver for I2C support: <URL url="http://www.raspberrypi.org/for.....-io/...
by Frank Buss
Wed May 09, 2012 2:58 am
Forum: Other projects
Topic: Linux device drivers for Rapberry Pi on-board I/O
Replies: 97
Views: 55857

Re: Linux device drivers for Rapberry Pi on-board I/O

<r>The driver is working now! The problem was the initialization order: The I2C-GPIO driver was initialized before the Broadcom GPIO driver. I"ve changed the GPIO driver initialization order to arch_initcall, which should be the right moment, because the GPIO pins should be available before any othe...
by Frank Buss
Tue May 08, 2012 5:11 am
Forum: Other projects
Topic: Linux device drivers for Rapberry Pi on-board I/O
Replies: 97
Views: 55857

Re: Linux device drivers for Rapberry Pi on-board I/O

<r>I've enabled the I2C GPIO support for both I2C interfaces, at the pin header and at the camera connector. I don't know if the third I2C interface at the HDMI connector is already handled by the GPU, so I didn't enabled this. This is the configuration (have to check the differences which resulted ...
by Frank Buss
Mon May 07, 2012 11:06 am
Forum: Other projects
Topic: C64 emulator
Replies: 103
Views: 76995

Re: C64 emulator

<r>Feel free to change the Wiki, maybe better not to use VIM I've got my Raspberry Pi now, too, you can avoid the audio cracks by changing the audio buffer size, Settings->Sound Settings->Sound Buffer size. 100 ms works good.<br/> <br/> But maybe it is a problem with the firmware. I've used this scr...
by Frank Buss
Mon May 07, 2012 6:38 am
Forum: Other projects
Topic: Linux device drivers for Rapberry Pi on-board I/O
Replies: 97
Views: 55857

Re: Linux device drivers for Rapberry Pi on-board I/O

<r>Lars T. Hansen said: <br/> <br/> In my opinion you should not dublicate work.<br/> Your first version already exists in the kernel tree! : Line 2 of i2c-gpio.c has this text "Bitbanging I2C bus driver using the GPIO API", and it is here: <URL url="http://lxr.linux.no/#linux+v3......2c/busses/">ht...
by Frank Buss
Sat May 05, 2012 8:01 pm
Forum: Other projects
Topic: Linux device drivers for Rapberry Pi on-board I/O
Replies: 97
Views: 55857

Re: Linux device drivers for Rapberry Pi on-board I/O

<t>I saw that coming Ok, I'll try it. I'll have some time for it on Monday. A public github repository sounds good.<br/> <br/> The first version will use the Linux bitbanging interface, which should be fairly easy. There is already an I2C driver which does this for the BCM5365. Should be sufficient ...
by Frank Buss
Fri May 04, 2012 7:44 pm
Forum: Other projects
Topic: Linux device drivers for Rapberry Pi on-board I/O
Replies: 97
Views: 55857

Re: Linux device drivers for Rapberry Pi on-board I/O

<t>Any news on the I2C driver? I have a Raspberry Pi and I have I2C slave devices for testing. I could even write the driver by myself, because I did some commercial driver development for another embedded Linux system, but I would like to avoid duplicate work But if you have something for testing, ...
by Frank Buss
Fri Apr 20, 2012 10:08 am
Forum: General discussion
Topic: Easy GPIO Hardware & Software
Replies: 133
Views: 51442

Re: Easy GPIO Hardware & Software

<t>Yes, there are 8 bit level converters, like SN74LVC8T245. I think ULN2003 should work, too, but it can just drive in open collector style, so might be useful for switching lamps, but e.g. not for driving a H-bridge for motor control. For such applications the MIC4421/4422 is nice, or use just a g...
by Frank Buss
Fri Apr 20, 2012 8:56 am
Forum: General discussion
Topic: Easy GPIO Hardware & Software
Replies: 133
Views: 51442

Re: Easy GPIO Hardware & Software

<r>There is an example how to access the GPIOs without /sys/class:<br/> <br/> <URL url="http://elinux.org/Rpi_Low-leve.....eripherals">http://elinux.org/Rpi_Low-leve.....eripherals</URL><br/> <br/> The datasheet at <URL url="http://www.raspberrypi.org/wp-.....herals.pdf">http://www.raspberrypi.org/w...
by Frank Buss
Thu Apr 19, 2012 2:23 pm
Forum: HATs and other add-ons
Topic: simple 16 signal GPIO I2C board
Replies: 31
Views: 18680

Re: simple 16 signal GPIO I2C board

pin headers are now included in the price
by Frank Buss
Thu Apr 19, 2012 12:17 pm
Forum: HATs and other add-ons
Topic: simple 16 signal GPIO I2C board
Replies: 31
Views: 18680

Re: simple 16 signal GPIO I2C board

<t>hamjudo said: <br/> <br/> <br/> Can you add other shipping options for shipping to the US?<br/> <br/> For 1 or 2 boards, the online store tells me that the cheapest shipping option, UPS Saver, is 55.99EUR.<br/> <br/> The datasheet shows the "Condition on delivery" as with some pins soldered on. I...
by Frank Buss
Thu Apr 19, 2012 8:50 am
Forum: HATs and other add-ons
Topic: simple 16 signal GPIO I2C board
Replies: 31
Views: 18680

Re: simple 16 signal GPIO I2C board

<r>You can buy it now!<br/> <br/> http://shop.trenz-electronic.d.....anguage=en<br/> <br/> And I've tried to create a datasheet for it:<br/> <br/> <URL url="http://www.frank-buss.de/io-ex.....pander.pdf">http://www.frank-buss.de/io-ex.....pander.pdf</URL><br/> <br/> Needs still a bit of work, this i...
by Frank Buss
Sun Apr 15, 2012 2:50 am
Forum: HATs and other add-ons
Topic: simple 16 signal GPIO I2C board
Replies: 31
Views: 18680

Re: simple 16 signal GPIO I2C board

<r>Good news: The tests are finished. I've created a test circuit with another simple project I've developed ( <URL url="http://www.frank-buss.de/displ.....index.html">http://www.frank-buss.de/displ.....index.html</URL> ). With two 4051 multiplexers and the analog input of the PIC, I measure each ou...
by Frank Buss
Mon Apr 09, 2012 10:00 pm
Forum: HATs and other add-ons
Topic: simple 16 signal GPIO I2C board
Replies: 31
Views: 18680

Re: simple 16 signal GPIO I2C board

<r>Got the first batch of 100 boards. I forgot one 2 mm trace to route, for the address coding pin header, but I patched already 50 boards (see below) and soldered the address pin header, I'll do the rest tomorrow. I've built a test setup with pogo test pins (nice tutorial how you can do this: <URL ...
by Frank Buss
Wed Apr 04, 2012 5:03 pm
Forum: Other projects
Topic: C64 emulator
Replies: 103
Views: 76995

Re: C64 emulator

I've created a page in the wiki how to install and run the C64 emulator VICE on the RPi:

http://elinux.org/RPi_VICE_C64_Emulator

Tested in the VM, would be cool if someone with the real hardware could test it.
by Frank Buss
Wed Mar 28, 2012 4:52 am
Forum: HATs and other add-ons
Topic: Gertboard
Replies: 258
Views: 109631

Re: Gertboard

You don't need a reflow oven for soldering SMD resistors. I think it is even easier to solder than through hole components, if it is some reasonable size, like 0805 and not 0201.
by Frank Buss
Mon Mar 26, 2012 6:15 pm
Forum: General discussion
Topic: New RS Email - Compliance?
Replies: 100
Views: 20720

Re: New RS Email - Compliance?

<t>Sounds a bit suspicious: "Raspberry Pi did a first trial run in a test chamber". And no results? From the tests I've seen, you know immediately by viewing the curves on the measurement devices, if you passed or failed, and you can try to fix it on the spot, if failed, like trying different cases ...
by Frank Buss
Sat Mar 24, 2012 5:35 am
Forum: General discussion
Topic: New RS Email - Compliance?
Replies: 100
Views: 20720

Re: New RS Email - Compliance?

<r>jamodio said: <br/> <br/> Very interesting and great find, and the picture was posted 10+ days ago !!<br/> Thanks, I found it in this Tweet from RS Electronics to Raspberry Pi, 11 days ago:<br/> <br/> <URL url="https://twitter.com/#!/RSElectronics/status/179552684578312192"><LINK_TEXT text="https...
by Frank Buss
Sat Mar 24, 2012 5:14 am
Forum: General discussion
Topic: New RS Email - Compliance?
Replies: 100
Views: 20720

Re: New RS Email - Compliance?

<r>Testing at RS: <URL url="http://ow.ly/i/vrZY/original">http://ow.ly/i/vrZY/original</URL><br/> <br/> Looks like there are some spikes (you can click on the image for a higher resolution version), but of course, I don't know the reference for the scale, but the engineer doesn't look happy <br/> <b...
by Frank Buss
Fri Mar 23, 2012 10:29 pm
Forum: General discussion
Topic: New RS Email - Compliance?
Replies: 100
Views: 20720

Re: New RS Email - Compliance?

<t>And would be interesting to hear something about the other regulations, like CE and WEEE for Europe, and all the other regulations required for different countries. I hope this will not delay it even more. Some regulations, like WEEE, don't care, if you label it as a development board. If the aut...
by Frank Buss
Wed Mar 21, 2012 9:41 pm
Forum: General discussion
Topic: Easy GPIO Hardware & Software
Replies: 133
Views: 51442

Re: Easy GPIO Hardware & Software

Maybe a good place to collect your wisdom, like the pull up resistors on the board, could be http://elinux.org/RPi_Low-leve.....eripherals , which then should be referenced by the FAQ.
by Frank Buss
Mon Mar 19, 2012 6:53 pm
Forum: HATs and other add-ons
Topic: Gertboard
Replies: 258
Views: 109631

Re: Gertboard

<t>I like Google Code, Sourceforge is nice, too. Both provide a version management system (SVN is easy with TurtoiseSVN for Windows and other tools for Linux), which makes it easier, if more than one works on the project and if you want to compare your code to old versions, if you deleted or refacto...
by Frank Buss
Thu Mar 08, 2012 6:40 am
Forum: HATs and other add-ons
Topic: simple 16 signal GPIO I2C board
Replies: 31
Views: 18680

Re: simple 16 signal GPIO I2C board

<t>The MCP23017 looks good. Compared to the PCA9555 it is nice to configure the pins as open collector and the advanced interrupt configurations. But looks like it doesn't have ESD protection for static discharges.<br/> <br/> Jumper selectable pull-ups for SDA and SCL would be a good idea, but the v...
by Frank Buss
Wed Mar 07, 2012 12:17 pm
Forum: General discussion
Topic: Easy GPIO Hardware & Software
Replies: 133
Views: 51442

Re: Easy GPIO Hardware & Software

<r>For me it looks like the datasheet ( <URL url="http://www.raspberrypi.org/wp-.....herals.pdf">http://www.raspberrypi.org/wp-.....herals.pdf</URL> ) says, that you can program a pullup or pulldown function with the GPPUD register (page 100/101) and then with the GPPUDCLK0/1 register for which pins...
by Frank Buss
Mon Mar 05, 2012 9:49 am
Forum: HATs and other add-ons
Topic: Gertboard
Replies: 258
Views: 109631

Re: Gertboard

<t>Gert said: <br/> <br/> <br/> 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.<br/> <br/> <br/> If you are using Eagle, you need just...

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