How to sets values to differents CS? about py-spidev HOT 4 CLOSED

hi sophiekovalevsky, the following example demonstrate how you can set channel 0 to cshigh=True and channel 1 to cshigh=False. I am not sure this is the only way to achieve this, but it seems to work.

import spidev
spi0 = spidev.SpiDev()
spi0.open(0, 0)
spi0.cshigh = True

spi1 = spidev.SpiDev()
spi1.open(0, 1)
spi1.cshigh = False

You can now use say spi0.xfer for channel 0 and spi1.xfer for channel 1.

from py-spidev.

I've been grappling with low-level SPI recently, trying to figure out how to not assert a chip-select line at all so I can control 4 devices instead of two. So hopefully I'm not going to spout complete nonsense.

The chip select lines correspond to the SPI device you pick with spi.open(). The first argument being the SPI bus number and the second being either 0 for CS0 ( BCM 8 ) or 1 for CS1 ( BCM 7 ) : http://pinout.xyz/pinout/spi

If you want to use any pin, you can just assert it manually before an xfer, while it's super handy to have the SPI library take care of chip-select for you ( and probably ever so slightly faster ), it's certainly not necessary.

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Thanks for the quick response.
So, if I have to instance of the spi library, which mean that I'm using the two ports that my embedded offer, how do I know which port affect the cshigh method?

Thanks a lot.

from py-spidev.

Thanks a lot.

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