RE: MISO lines skipping a bit on nrf52840dk using the stm lsm6dsv16x.

hmolesworth — Thu, 05 Jun 2025 22:40:27 GMT

Often traces such as those included in the post are misleading as they are not true signals but instead interpreted signals displayed as binary on a logic analyser when in fact they are sloppy-edge signals with a finite rise- and fall-time, not square at all. Should an analogue display mode or better still an analogue oscilloscope be available this would become apparent. Worse, the logic analyser may not use the same voltage thresholds as the nRF52840 to determine the edge locations.

However, no matter; the usual fix is to start by boosting the drive strength for /CS, SCK and MOSI to H0H1 (High-Drive) to get sharper edges (MISO doesn't matter):

    spi2_default: spi2_default {
        group1 { psels = <NRF_PSEL(SPIM_SCK, 0, 28)>,
                         <NRF_PSEL(SPIM_MOSI, 0, 29)>,
                         <NRF_PSEL(SPIM_MISO, 0, 31)>;
                 nordic,drive-mode = <NRF_DRIVE_H0H1>;
		};

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