morind79
Posts: 27
Joined: Mon Oct 29, 2012 8:51 am

GPIO Board development

Thu Dec 20, 2012 1:53 pm

Hi all,

I am creating a GPIO board for my home automation. Of course it can be also used to do other things :)
I have already created one, but found some trouble on it, so I am designing a second one.

Here is the schematic I have already done :
GPIO_V2.zip
(37.6 KiB) Downloaded 501 times
The board has :
64 digital IOs, each 8 pairs of IO are set either in input or output at 5V level
1 RS232 serial port
1 UART port (3.3V signal level)
1 GSM module
1 RTC
2 I2C port (5V level)

The issue I have is for the level converter on the GSM modem. I am not sure that it is correct like that (See U18 and U19).

If somebody can check and let me know if this schematic is ok, the more eyes are looking, the less error it has :D

thank you

Best regards

Denis

User avatar
TonyD
Posts: 450
Joined: Thu Sep 08, 2011 10:58 am
Location: Newcastle, UK
Contact: Website

Re: GPIO Board development

Thu Dec 20, 2012 9:14 pm

Wow, that's a pretty impressive board you've done. Looking forward to seeing it when its made
Tony

morind79
Posts: 27
Joined: Mon Oct 29, 2012 8:51 am

Re: GPIO Board development

Fri Dec 21, 2012 8:34 pm

Thank you TonyD :-)

Well I do my best to create a board that will be good for several things.

Nobody can help me on this schematic ?

For now I set up 2 libraries using the excellent Pi4J, I am able to use a I2C LCD screen, and also using the RTC DS3231.

Thank you

Best regards,

Denis

morind79
Posts: 27
Joined: Mon Oct 29, 2012 8:51 am

Re: GPIO Board development

Sun Dec 23, 2012 11:54 am

Hi,

After some nights, I have changed the schematic a little bit. In fact instead having voltage converter after MCP23x17, I put them before, this way the schematic is simple.

Here is what I have now :
GPIOV3.zip
(32.31 KiB) Downloaded 238 times
Do not know if SPI will work like this. Never tested it.

Again, all comments are welcome :-)

Thank you

Best regards

Denis

User avatar
fulburncams
Posts: 70
Joined: Wed Nov 30, 2011 8:29 pm

Re: GPIO Board development

Sun Dec 23, 2012 12:36 pm

Have done something similar with RS232, I2C ic's ( A2D/D2a and PIO PCF8591 and 8574), RTC (DS1307)and motor controller L298. I used the wiringPi code in conjunction with JNI to get Java working. . http://www.fulburncams.gb.net/

Good Luck Cheers
Steve

morind79
Posts: 27
Joined: Mon Oct 29, 2012 8:51 am

Re: GPIO Board development

Thu Jan 03, 2013 1:25 pm

Hi,

After this end of year period, I finished the schematic for the GPIO board.
Here is the latest version :
GPIOV3.zip
(34.43 KiB) Downloaded 239 times
Please have a look and let me know if you have some comments.
I will create Gerber X files to build the PCB.

thank you

Best regards

Denis

mjtessmer
Posts: 27
Joined: Sun Nov 20, 2011 12:50 am

Re: GPIO Board development

Thu Jan 03, 2013 6:30 pm

I have a question about the power supply circuit section.
Is the USB1 connector a power in or power out?
If USB1 is power in, I suggest an in-line diode going from
the USB V+ to the 4.3 volt.

morind79
Posts: 27
Joined: Mon Oct 29, 2012 8:51 am

Re: GPIO Board development

Thu Jan 03, 2013 7:06 pm

Hi,

Thank you for your answer. The USB connector is here to power up the Raspberry Pi board.
I know doing things like this, as the +5 is also connected to the GPIO port, then the polyfuse on the Raspberry will be shorted, but this is not a problem, in fact these polyfuse are not necessary.
In fact the GPIO board and the Raspberry will be powered by thePJ1 connector, a PSU of 7 to 12V should be connected on this PL1 connector. I did this because the SIM900 GSM module needs more than 1A... so this AP1512A, it can deliver up to 3A (of course if the PSU can do this :-) ).

Best regards

Denis

morind79
Posts: 27
Joined: Mon Oct 29, 2012 8:51 am

Re: GPIO Board development

Tue Feb 05, 2013 10:15 am

Hi all,

I have created the new GPIO board named RaspExt.
You can have more information on it :

http://raspext.com/

Please leave me your comments.

Best regards

Denis

d0vr
Posts: 26
Joined: Sun Oct 28, 2012 11:25 am

Re: GPIO Board development

Sat Feb 16, 2013 2:22 pm

morind79 wrote:I have created the new GPIO board named RaspExt.
Hi Denis, are you selling the board, or is it free to make/use?

morind79
Posts: 27
Joined: Mon Oct 29, 2012 8:51 am

Re: GPIO Board development

Sat Feb 16, 2013 8:43 pm

Hi d0vr,

You can use the data to manufacture it for free, no problem.
If you have more question, please go on the RaspExt website, there is also a forum dedicated to the board.

Best regards
Denis

morind79
Posts: 27
Joined: Mon Oct 29, 2012 8:51 am

Re: GPIO Board development

Wed Aug 07, 2013 1:23 pm

Hi all,

Just to let you know I have updated the raspext blog, now there is a new code to handle SIM900 modules.

Best regards

Denis

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