https://devzone.nordicsemi.com/f/nordic-q-a/25626/spi-nrf52-5v-arduino-logic-levelsHi, I had some erratic results when I hook these devices via SPI, using a level shifter (e.g. TXB0104) to protect the nRF52. When I look at the schematic for the nRF52-DK I see that there is no level shifting on the pins intended for Arduino shieldsen-USTelligent Community 13Thu, 05 Oct 2017 08:38:32 GMThttps://devzone.nordicsemi.com/thread/101004?ContentTypeID=1Thu, 05 Oct 2017 08:38:32 GMT137ad170-7792-4731-bb38-c0d22fbe4515:33024c8a-1620-4ea9-9141-351c82ebbdb2ovrebekk<p>Good to hear that you got it working :)</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/101003?ContentTypeID=1Wed, 04 Oct 2017 13:02:09 GMT137ad170-7792-4731-bb38-c0d22fbe4515:83569b81-b11f-4303-a1b4-e611c420f8a8paul_tanner<p>Thx @Torbjørn</p> <p>I have confirmed that the electrical connection works fine with level shifters. I had some issues with the firmware on the Arduino-style slave device. I lowered the clock rate and made sure that the slave can respond rapidly enough using interrupts and pre-buffered data. Now it works fine.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/101002?ContentTypeID=1Wed, 04 Oct 2017 06:24:59 GMT137ad170-7792-4731-bb38-c0d22fbe4515:a2bd50d6-5023-42e6-beb2-6e5de18661aeovrebekk<p>Hi Paul</p> <p>The nRF52-DK is not 5V tolerant, but many Arduino shields will work fine with 3-3.3V signals.</p> <p>In other words I would not connect your device directly, but rather try to figure out what is wrong with the level shifter connection.<br /> Do you have a scope available so you can see what is going on on the lines?<br /> What SPI frequency are you running at?</p> <p>As a side note, the nRF52840 has a high voltage mode that makes it 5V tolerant, but this device is not yet in production (we have a preview DK available for development).</p> <p>Best regards<br /> Torbjørn</p><div style="clear:both;"></div>