Merge pull request #294 from jaredairbusaerial/patch-1

Improved power connection procedure information

docs/getting-started.md

@@ -56,14 +56,19 @@ All non-power I/O is 3.3V output and 5V tolerant on input, on ODrive v3.3 and ne
 
 ### Wiring up the motors
 * Connect the motor phases into the 3-phase screw terminals. It is not recommended to use a clip-on connector such as an alligator clip, as this can cause issues with the phase resistance/inductance measurements. 
-* Connect the power source to the DC terminals. Make sure to pay attention to the polarity.
-* Do not apply power just yet.
 
 ### Wiring up the encoders
 Connect the encoder(s) to J4. The A,B phases are required, and the Z (index pulse) is optional. The A,B and Z lines have 3.3k pull up resistors, for use with open-drain encoder outputs. For single ended push-pull signals with weak drive current (\<4mA), you may want to desolder the pull-ups.
 
 ![Image of ODrive all hooked up](https://docs.google.com/drawings/d/e/2PACX-1vTCD0P40Cd-wvD7Fl8UYEaxp3_UL81oI4qUVqrrCJPi6tkJeSs2rsffIXQRpdu6rNZs6-2mRKKYtILG/pub?w=1716&h=1281)
 
+### Safety & Power UP
+<div class="alert">
+ Always think safety before powering up the ODrive if motors are attached. Consider what might happen if the motor spins as soon as power is applied.
+</div>
+* Unlike some devices, the ODrive does not recieve power over the USB port so the 24/48 volt power input is required even just to communicate with it using USB. It is ok to power up the ODrive before or after connecting the USB cable.
+* To power up the ODrive, connect the power source to the DC terminals. Make sure to pay attention to the polarity. A small spark is normal. This is caused by the capacitors charging up.
+
 ## Downloading and Installing Tools
 Most instructions in this guide refer to a utility called `odrivetool`, so you should install that first.