Using more that 2 CE pins with SPI, is it possible with this library ?

[stephend61]

Hi, I am trying to connect 5 MCP3008 chips to a raspbery pi 4 B, but can't work out how to address them all, has anyone else done something similar ?

I have added the extra chipselect entries, but I can't see a way of using them with this library, is it possible ?
Or maybe some other way, preferably with Java.

I have it working with 2 at the meoment.

ls -la /dev/spi*
crw-rw---- 1 root spi 153, 3 Oct 20 22:17 /dev/spidev0.0
crw-rw---- 1 root spi 153, 4 Oct 20 22:17 /dev/spidev0.1
crw-rw---- 1 root spi 153, 2 Oct 20 22:17 /dev/spidev0.2
crw-rw---- 1 root spi 153, 1 Oct 20 22:17 /dev/spidev0.3
crw-rw---- 1 root spi 153, 0 Oct 20 22:17 /dev/spidev0.4

Thanks.
Regards
Stephen.

[stephend61]

Don't worry I worked it out, I now have all 5 working using pi4j, thanks.

[FDelporte]

Hi @stephend61 , how did you fix, is it something we should document on pi4j.com?

[stephend61]

I ended up just using gpio pins to control the chip select and ignored the 2 default select pins, since I need 5 select pins and couldn't work out how to expand what pi4j had available, if there is a better way please let me know.

Thanks.

[taartspi]

At present time that is the simple way to have more than 2 CE lines. If gpios are limited a gpio expander chip via i2c is usable although i wonder if its operation would be slower. At any rate the present pigpio spi provider has these limits. We are working on a new spi provider as it is required for the model Pi5. We will make sure we do not have this limitation.

[stephend61]

Sounds good might eventually move to the Pi 5, so will look at making the change then, thanks