nrf52dk cannot find max30101 breakout board over i2chttps://devzone.nordicsemi.com/f/nordic-q-a/128371/nrf52dk-cannot-find-max30101-breakout-board-over-i2cHi, I am using the heart rate sample. I have connected ground to ground, 3.3v to vdd, SDA to pin 26 and SCL to pin 27. I have 4.7k pullup resistors on SDA and SCL. When I run i2c scan i2c0 i get: 0 1 2 3 4 5 6 7 8 9 a b c d e f 00: -- -- -- -- en-USTelligent Community 13Mon, 08 Jun 2026 13:47:18 GMTRE: nrf52dk cannot find max30101 breakout board over i2chttps://devzone.nordicsemi.com/thread/567549?ContentTypeID=1Mon, 08 Jun 2026 13:47:18 GMT137ad170-7792-4731-bb38-c0d22fbe4515:6c93bf5f-4a5a-4987-883e-b6121abb0959hemmie<p>Thank you so much it works now!</p><div style="clear:both;"></div>RE: nrf52dk cannot find max30101 breakout board over i2chttps://devzone.nordicsemi.com/thread/567545?ContentTypeID=1Mon, 08 Jun 2026 13:04:11 GMT137ad170-7792-4731-bb38-c0d22fbe4515:a096eb30-f3c8-42c2-bf5a-113b96a045c4Ressa<p>Hi,<br /><br />Your current &amp;i2c0 block doesn&#39;t reference the pinctrl states you defined, so the pins are never actually configured. Here is the corrected overlay:<br /><br /><img style="max-height:240px;max-width:320px;" src="https://devzone.nordicsemi.com/resized-image/__size/640x480/__key/communityserver-discussions-components-files/4/pastedimage1780923784590v1.png" alt=" " /><br /><br /><br /><br /></p><div style="clear:both;"></div>RE: nrf52dk cannot find max30101 breakout board over i2chttps://devzone.nordicsemi.com/thread/567531?ContentTypeID=1Mon, 08 Jun 2026 10:34:41 GMT137ad170-7792-4731-bb38-c0d22fbe4515:78c265e9-5bdb-44cb-9e9c-6548a1f5acb9hemmie<p>From nrf52dk_nrf52832-pinctrl.dtsi: This would mean that 26 and 27 are correct right? I have swapped the wires between them and tried the scan multiple times each and nothing worked.&nbsp;</p> <div style="background-color:#1f1f1f;color:#cccccc;font-family:Consolas, &#39;Courier New&#39;, monospace;font-size:14px;font-weight:normal;line-height:19px;white-space:pre;"> <div><span style="color:#4ec9b0;">i2c0_default:</span><span style="color:#cccccc;"> </span><span style="color:#4ec9b0;">i2c0_default</span><span style="color:#cccccc;"> {</span></div> <div><span style="color:#cccccc;">&nbsp; &nbsp; &nbsp; &nbsp; </span><span style="color:#4ec9b0;">group1</span><span style="color:#cccccc;"> {</span></div> <div><span style="color:#cccccc;">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </span><span style="color:#9cdcfe;">psels</span><span style="color:#cccccc;"> </span><span style="color:#d4d4d4;">=</span><span style="color:#cccccc;"> &lt;</span><span style="color:#569cd6;">NRF_PSEL</span><span style="color:#cccccc;">(</span><span style="color:#569cd6;">TWIM_SDA</span><span style="color:#cccccc;">, </span><span style="color:#b5cea8;">0</span><span style="color:#cccccc;">, </span><span style="color:#b5cea8;">26</span><span style="color:#cccccc;">)&gt;,</span></div> <div><span style="color:#cccccc;">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &lt;</span><span style="color:#569cd6;">NRF_PSEL</span><span style="color:#cccccc;">(</span><span style="color:#569cd6;">TWIM_SCL</span><span style="color:#cccccc;">, </span><span style="color:#b5cea8;">0</span><span style="color:#cccccc;">, </span><span style="color:#b5cea8;">27</span><span style="color:#cccccc;">)&gt;;</span></div> <div><span style="color:#cccccc;">&nbsp; &nbsp; &nbsp; &nbsp; };</span></div> <div><span style="color:#cccccc;">&nbsp; &nbsp; };</span></div> <br /> <div><span style="color:#cccccc;">&nbsp; &nbsp; </span><span style="color:#4ec9b0;">i2c0_sleep:</span><span style="color:#cccccc;"> </span><span style="color:#4ec9b0;">i2c0_sleep</span><span style="color:#cccccc;"> {</span></div> <div><span style="color:#cccccc;">&nbsp; &nbsp; &nbsp; &nbsp; </span><span style="color:#4ec9b0;">group1</span><span style="color:#cccccc;"> {</span></div> <div><span style="color:#cccccc;">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </span><span style="color:#9cdcfe;">psels</span><span style="color:#cccccc;"> </span><span style="color:#d4d4d4;">=</span><span style="color:#cccccc;"> &lt;</span><span style="color:#569cd6;">NRF_PSEL</span><span style="color:#cccccc;">(</span><span style="color:#569cd6;">TWIM_SDA</span><span style="color:#cccccc;">, </span><span style="color:#b5cea8;">0</span><span style="color:#cccccc;">, </span><span style="color:#b5cea8;">26</span><span style="color:#cccccc;">)&gt;,</span></div> <div><span style="color:#cccccc;">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &lt;</span><span style="color:#569cd6;">NRF_PSEL</span><span style="color:#cccccc;">(</span><span style="color:#569cd6;">TWIM_SCL</span><span style="color:#cccccc;">, </span><span style="color:#b5cea8;">0</span><span style="color:#cccccc;">, </span><span style="color:#b5cea8;">27</span><span style="color:#cccccc;">)&gt;;</span></div> <div><span style="color:#cccccc;">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </span><span style="color:#9cdcfe;">low-power-enable</span><span style="color:#cccccc;">;</span></div> <div><span style="color:#cccccc;">&nbsp; &nbsp; &nbsp; &nbsp; };</span></div> <div><span style="color:#cccccc;">&nbsp; &nbsp; };</span></div> </div><div style="clear:both;"></div>RE: nrf52dk cannot find max30101 breakout board over i2chttps://devzone.nordicsemi.com/thread/567513?ContentTypeID=1Mon, 08 Jun 2026 07:39:46 GMT137ad170-7792-4731-bb38-c0d22fbe4515:3fdd5885-857f-4bd7-a339-c70ba40655a6Turbo J<p>Check the dts files in the build folder - pin config is also in DTS and may not be what you expected.</p><div style="clear:both;"></div>