SPI instead of SHIFTOUT - MAX7219

[Darrel Taylor]

It looks like the While loop is blocking the process (or like SSPIF is never set). if I suppress the while loop the PORTB.0 will toggle again.

That's the reason why I thought about setting the interrupts.

Works fine here.
Ran your program (with the suggested changes) on an 877, and It sends data from the SSP and blinks the LED.

It's A VERY FAST blink. Not visible to the naked eye (or clothed ones).

Try putting a PAUSE 200 in the Main Loop.
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[Momboz]

Works fine here.
Ran your program (with the suggested changes) on an 877, and It sends data from the SSP and blinks the LED.

It's A VERY FAST blink. Not visible to the naked eye (or clothed ones).

Try putting a PAUSE 200 in the Main Loop.
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Dear DT

I would like, first, to thank you very very much for your support and then I wish to give you a feedback on how far I went with my SPI interface.

After some investigation I could find the reason of the problem I have making SPI running on my board. It is a hardware issue. It's the way I am using the Melabs PICPROTO-USB board. That doesn't mean that Melabs PICPROTO-USB board is faulty.

On that board you have the possibility to use the USB board in high speed. Therefore you need a capacitor C7 (0.470 µF) as shown in the documentation of that Melabs board (http://www.melabs.com/downloads/ppusbsch_06.pdf). This seems to prevent the SPI interface for running properly. I have taken the C7 away and everything went fine with SPI interface.

Maybe we will have a new Melabs board with a jumper that could leave this capacitor out when using the SPI interface

For the time being I have to make a choice for by Melabs board usage: either using USB high speed (and put the C7 capacitor) or using SPI (and take away the capacitor).

Once again many thanks for your help.

Best wishes / Momboz

[Darrel Taylor]

Good find Momboz!

I see you mentioned the PICPROTO-USB up in post #3.
But I never even looked at the schematic.

For the time being I have to make a choice for by Melabs board usage: either using USB high speed (and put the C7 capacitor) or using SPI (and take away the capacitor).

If you're using a PIC with USB, the SPI interface will be on different pins, so it shouldn't be a problem.
But you're right. meLabs should have put a jumper in there for the capacitor.

Cheers!