NRF54L15 SPIS

RE: NRF54L15 SPIS

Susheel Nuguru — Mon, 14 Apr 2025 07:44:46 GMT

I think you may be right here, that the SPIS driver in NCS might be needing to have an empty buffer set when you are using spi_transceive_signal the way you are using. But maybe we can try this.

After the SPI driver is initialized, you can use nrfx_spis_buffers_set to set the default TX and RX buffers. This way we are high jacking the nrfx use while using the Zephyr based SPIS driver, but I think it might be safe to do so right after the init.
When you get a complete handler, you set the next buffers using nrfx_spis_buffers_set to set the buffers again.

This might help but I am unsure if I should be suggesting you to use nRFX while using the Zephyr based driver. Otherwise, if you use only Zephyr based driver, then method 2 seems to need to have that extra transmission

RE: NRF54L15 SPIS

hanks.liu — Thu, 10 Apr 2025 12:04:16 GMT

thanks,
In other words:

I want to know how to change the slave send buffer data before the master initiates Spi communication next time after writing the slave send buffer data in spi_transceive_signal(spi_slave_dev, spi_slave_cfg, &s_tx, &s_rx, p_spi_slave_done_sig). I tried k_poll_signal_reset(p_spi_slave_done_sig) and then calling spi_transceive_signal again to write data. I found that the program would be blocked here.

RE: NRF54L15 SPIS

Simonr — Thu, 10 Apr 2025 09:29:24 GMT

I'm not sure I understand what you're saying here, but it sounds to me like you're just describing how a SPI slave should work. Since it is a slave it just waits/listens to the master to give it "instructions" before doing anything. You can directly write, but then the master won't know to listen by default I think.

Best regards,

Simon