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Topic: 7 Segment Display using SPI (Read 10 times) previous topic - next topic

Ran Talbott

Also, Busaboi doesn't call up the SPI.h library that I have seen.

The SPI library is very small.  Busaboi just put the code he needed inline.

Assuming his code is good for 1 display (which I think has already been confirmed),  simply changing the slave select from a constant to a variable should be all you need to get it to work for 3.

There's not a whole lot to understand with SPI:  the really hard part is figuring out the "mode" (clock polarity and phasing),  because SPI didn't start out as an official standard.  So different chip makers did their own variations,  and SPI never got formalized like I2C or USB.  Sometimes you also need to be careful with the timing of slave select,  or the pacing of transmitted bytes,  but usually you can just go as fast as possible.

You've already got that right,  so it's just a matter of stuffing bytes into the SPI transmit register in groups of 4 (and,  in this case,  ignoring the received data).


works just fine for me but i can't figure out how to send commands to change brightness or turn on the colon.  anyone know how to do this?


Hi every body,

I'm new with arduino. I tried to display "1234" with serial like this :
Code: [Select]

RX      ->  PIN TX  
VCC   ->  PIN  3.3V

Code: [Select]
void setup(){
void loop() {

It display lot of thing but but "1234" !

I writed this dirty code from the documentation on sparkfun website.



@2xyo - These 7 segment displays have two physical interfaces. This topic thread is about SPI, and you're trying to use the Serial interface.

See the thread at: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1249525950/2 about using Serial with this display. Working code is shown in that thread.

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