title: How to configure Visual Studio Code includePath for Arduino and Teensy
body: <p>I'm working with Arduino and Teensy boards from inside VS code. I can build and program everything fine, but the highlighting and code following functions built into VS Code don't work.</p>
  <p>Previously, my custom headers weren't loading or highlighting, but <a href="https://stackoverflow.com/questions/52234438/vs-code-giving-header-errors-for-arduino-missing-official-header/52343289">this answer</a> got that working for me. Now I have the right libraries on my include path (and I can click and follow them to the correct source) but some names still don't work:</p>
  <p><a href="https://i.stack.imgur.com/251MX.png" rel="noreferrer"><img src="https://i.stack.imgur.com/251MX.png" alt="enter image description here" /></a></p>
  <p><a href="https://i.stack.imgur.com/zvg17.png" rel="noreferrer"><img src="https://i.stack.imgur.com/zvg17.png" alt="enter image description here" /></a></p>
  <p>My <code>includePath</code> appears to be configured correctly, as I mentioned I can follow the includes and it opens the correct sources:</p>
  <pre><code>&quot;includePath&quot;: [
      &quot;${workspaceFolder}/**&quot;,
      &quot;C:/Program Files (x86)/Arduino/**&quot;,
      &quot;C:/Program Files (x86)/Arduino/hardware/teensy/avr/cores/teensy/**&quot;,
      &quot;C:/Program Files (x86)/Arduino/hardware/teensy/avr/libraries/ADC/**&quot;,
      &quot;C:/Program Files (x86)/Arduino/hardware/arduino/avr/cores/arduino/**&quot;,
      &quot;C:/Program Files (x86)/Arduino/hardware/arduino/avr/variants/standard/**&quot;,
      &quot;C:/Program Files (x86)/Arduino/hardware/tools/avr/lib/gcc/avr/5.4.0/include/**&quot;
  ]
  </code></pre>
  <p>I can confirm the header is on the includePath and has the names defined I'm looking for:</p>
  <p><a href="https://i.stack.imgur.com/ZGJAU.png" rel="noreferrer"><img src="https://i.stack.imgur.com/ZGJAU.png" alt="enter image description here" /></a></p>
  <p>Somehow VS Code is still saying the identifier is undefined.</p>
  <p>Any ideas?</p>