Using MIPI-DBI-SPI display and SPI sensor on same bus

RE: Using MIPI-DBI-SPI display and SPI sensor on same bus

Håkon Alseth — Wed, 11 Jun 2025 10:28:37 GMT

Hi,

[quote user="Dhruvil Levelcon"]we cannot use a different pins as we are sharing a same spi bus[/quote]

Sorry, but I do not understand. Why are you connecting DC to MISO? Those are two different purposes, and as pointed out; will create a conflict.

Kind regards,

Håkon

RE: Using MIPI-DBI-SPI display and SPI sensor on same bus

Dhruvil Levelcon — Wed, 11 Jun 2025 10:20:36 GMT

Hello,

Thanks for quick response

we cannot use a different pins as we are sharing a same spi bus and also we are short of pins on our controller.

So do you have any other options where we can use the same MISO pin?

Thanks

RE: Using MIPI-DBI-SPI display and SPI sensor on same bus

Håkon Alseth — Wed, 11 Jun 2025 10:17:29 GMT

Hi,

That will create a pin-conflict.

Try using different GPIOs for MISO/DC-pin and see if this helps.

Kind regards,

Håkon

RE: Using MIPI-DBI-SPI display and SPI sensor on same bus

Dhruvil Levelcon — Wed, 11 Jun 2025 09:41:10 GMT

hello Håkon

Thank You for your quick response.

Currently we have assigned a MISO Pin as a dc-gpio pin ( gpio0 12 )in our mipi-dbi-spi node for display. please do note that the same MISO pin is also used by our Sensor.

can we do that ?

&pinctrl {
    spi3_default_alt: spi3_default_alt {
        group1 {
            psels = <NRF_PSEL(SPIM_SCK, 0, 11)>,
                <NRF_PSEL(SPIM_MOSI, 0, 6)>,
                <NRF_PSEL(SPIM_MISO, 0, 12)>;
        };
    };

    spi3_sleep_alt: spi3_sleep_alt {
        group1 {
            psels = <NRF_PSEL(SPIM_SCK, 0, 11)>,
                <NRF_PSEL(SPIM_MOSI, 0, 6)>,
                <NRF_PSEL(SPIM_MISO, 0, 12)>;
            low-power-enable;
        };
    };
};

RE: Using MIPI-DBI-SPI display and SPI sensor on same bus

Håkon Alseth — Wed, 11 Jun 2025 08:26:29 GMT

Hi,

You shall define your mipi-node under the root-node, like shown here:

https://github.com/nrfconnect/sdk-zephyr/blob/v4.0.99-ncs1/boards/shields/seeed_xiao_round_display/seeed_xiao_round_display.overlay#L32-L49

And the amount of sensors on the chosen spi-node is determined how you declare that node. In the case of this specific board, it has 2 CSN pins, ie. 2 SPI slaves, defined:

https://github.com/nrfconnect/sdk-zephyr/blob/v4.0.99-ncs1/boards/shields/seeed_xiao_round_display/seeed_xiao_round_display.overlay#L84

Kind regards,

Håkon