Author Topic: Which pins on Daughterboard have SPI signals  (Read 5042 times)

OGraveland

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Which pins on Daughterboard have SPI signals
« on: September 05, 2011, 04:15:55 PM »
I have previously bought several SBC83IL-D232 boards from your company. I found information on the website about daughter boards, but I am not sure it is correct, or if it is, how to use it.

To quote the website: "The Daughter Board connector can be used as an expansion port to add additional functionality. It contains most of the free CPU port pins, power, I2C, SPI, RS232 signal, and more."
Could you tell me which pins on the daughter board connector are used for SPI?
(I actually dont think RS232 signals are available on the daughter board either, but I get those from the special I-mod modules)
« Last Edit: September 05, 2011, 07:47:24 PM by OGraveland »

modtro2

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Re: Which pins on Daughterboard have SPI signals
« Reply #1 on: September 12, 2011, 04:17:48 PM »
Hi, Y9, Y10 and Y11 of the daughter board connector are connected to RC3, RC4 and RC5 of the PIC. They can be used as a I2C or SPI port. For additional info, and circuit diagram please download SBC83IL datasheet from here:
www.modtronix.com/products/sbc83il

OGraveland

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Re: Which pins on Daughterboard have SPI signals
« Reply #2 on: September 12, 2011, 06:00:31 PM »
Hi modtro,
Thanks for your reply. However C3, C4 and C5 are ports of SSP1. They are configured as I2C, including pull-up resistors on the SBC83.
SSP2 of the PIC is related to D4, D5 and D6, those are not brought to the daughter board or to the IDC connectors.

I (currently) do not use the I2C EEPROM. Could i configure SSP1 as SPI without modifying the SBC83IL? (without removing EEPROM and without removing RA4 (not the port, but the resistors))

Thanks

modtro2

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Re: Which pins on Daughterboard have SPI signals
« Reply #3 on: September 18, 2011, 06:55:34 PM »
Hi, you will have to make a small modification to your board.

To use C3, C4 and C5 as SPI, you have to cut the 2 tracks going to the EEPROM. See attached pictures. Might also work if you just cut a single track, seeing that external EEPROM, should not interfere with SPI bus with a single line. I included a picture of tracks that have to be cut. After doing this, you can configure C3, C4 and C5 as SPI bus, and use it on daughter board.