title: Beagle Bone Black I2C2 Issues
body: <p>I am having troubles using an <a href="https://cdn-learn.adafruit.com/downloads/pdf/adafruit-htu21d-f-temperature-humidity-sensor.pdf" rel="nofollow noreferrer">I2C sensor</a> with the Beagle Bone Black (BBB). The BBB is running a newly flashed 18.04 Ubuntu image specifically for the BBB.</p>
  <p>I wired the sensor (VIN, GND, SCL, SDA) to the corresponding I2C2 pins (4, 2, 19, 20) on the BBB using the below pinout.</p>
  <p><a href="https://i.stack.imgur.com/UevBb.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/UevBb.png" alt="BBB Pinout" /></a>
  The sensor is supposed to be using address 0x40, but scanning I2C2 (using <code>i2cdetect -r 2</code>) does not show the sensor.</p>
  <p><a href="https://i.stack.imgur.com/DtNJZ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/DtNJZ.png" alt="i2cdetect -r 2 output" /></a></p>
  <p>I have tested this with two separate sensors as I thought at first I may have fried the original sensor somehow, but the results are the same. In fact, running the I2C2 scan command yields the exact same results when nothing is connected at all.</p>
  <p>I have read in many places that I2C2 may not be enabled by default, but I assume it is enabled in my case as I can scan I2C2 without getting an error. Is this assumption incorrect? Again, this is a freshly flashed BBB, and I have not enabled/disabled anything - it should be in the default state.</p>
  <p>I have also verified the connectivity of my wires between the sensor and BBB. The voltage between VIN and GND on the chip is 3.3V, so it is definitely being powered.</p>
  <p>Why can't I connect to my I2C sensors using the BBB?</p>