Multiple SPI instances - share pins?

[Daniel Reisfeld]

Hi,

I'm using NRF52840 sdk v15 with Softdevice.

I have multiple SPIM instances and I make sure they are never active at the same time.

Can I share the pins (except the CS one) between the instances?

Thanks,

Daniel

[Daniel Reisfeld]

1. Can I use nrf_spim_csn_configure also with the SPIM driver library to dynamically change the CS?

2. Using the SPIM driver library, I don't need to specify the duration parameter. Can you advise on the best way to determine this parameter?

Thanks,

Daniel

[haakonsh]

1. Yes, thought not during a transfer. 

2. It is given by the Slaves timing specification. I would start with 0 and if that does not work, increase until it does. I suggest you use a digital analyzer during this development. 

 

[Daniel Reisfeld]

Thanks again! I did indeed find the min duration for my slaves.

The SPI mode varies among my slaves. Can I also change it (and keep using the driver library)?

Thanks,

Daniel

[haakonsh]

Yes, with a call to nrf_spim_configure. 

This is basically what the spi transaction manager library does. It lets you define different configuration and swap between them, in addition to a basic queuing scheduler.  

[Daniel Reisfeld]

Thanks!

From the documentation at 

http://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.nrf52840.ps%2Fspim.html&cp=2_0_0_5_24&anchor=unique_1464866032__table.instances

Table 3

it seems that our discussion (and especially regarding the CS) applies only to SPIM3 (and not to SPIM0..SPIM2). Am i right?

Thanks again!

Daniel