Hi Matt,
On 01.08.14 08:41, mattschinkel wrote:
Why not use the SPI library for max7219_shift_data()?
SPI is faster, and you can connect multiple devices.
Thinking about this I found several reasons:
- I have not worked with SPI before and didn't think of using it!
- According to the max7219/7221 datasheet only the max7221 is
compatible (thus the 7219 apparently is not).
The max7219 is output only, there is nothing to read.
- Multiple max7219 can be chained / cascaded requiring only
a 5-wire 'bus' (incl the power lines)
- The 'addr' parameter in max7219_shift_data is not the address
of a max7219 chip but a commandcode frequently combined with
an offset of the LEDs being controlled with 'data'.
The specific chip is selected by sending NOP's to the other
chips in the same operation.
So SPI is probably not applicable here. Next time I'll hope to think of
reusable libraries.
Regards, Rob.
--
R. Hamerling, Netherlands --- http://www.robh.nl
--
You received this message because you are subscribed to the Google Groups
"jallib" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/jallib.
For more options, visit https://groups.google.com/d/optout.
