add led blink tutorial

en/firstinterhacktions.md

@@ -12,6 +12,7 @@ You need:
 <!-- usb-A to usb-C and usb-C to usb-C photo would be helpful here -->
 - an application for opening a serial connection, e.g. screen (installation via command line:`apt install screen`) or picocom (installation via command line: `apt install picocom`)
 
+### Getting to the interactive python command line
 Switch on your card10.
 If your card10 display shows the text _USB activated._ your card10 is in the _USB storage_ mode, which is the wrong mode for the interactive pythong command line. A brief press on the _power_ button will exit the _USB storage_ mode.
 <!-- a picture here, indicating the right button would be nice -->
@@ -22,10 +23,29 @@ You can find out what it is called on your machine by comparing the output of `l
 Depending on which tool you chose, you can open the interactive python command line
 - using screen: `screen /dev/ttyACM0 115200`
 - using picocom: `picocom -b 115200 /dev/ttyACM0`
+You might need to add "sudo" in front of the commands.
 
+If you don't see a line starting with _>>>_, try pressing _Ctrl+C_.
 
+<div class="p-notification--information">
+  <p class="p-notification__response">
+    <span class="p-notification__status">Note:</span>The first line gives you the version of your firmware, e.g. "MicroPython v1.11-37-g62f004ba4 on 2019-08-17; card10 with max32666".
+  </p>
+</div>
 
 
+Once you have a line starting with _>>>_, you are ready to start programming in python!
+
+### Making an LED blink
+
+There are some neat python functions prepared for making the leds blink. Let's import the library containing these functions by typing:
+```import leds```
+
+Next, we light up one of the r0kets by typing:
+```leds.set_rocket(0, 100)```
+
+The first number entered is the index for selecting the r0ket LED. You can choose between 0 and 2.
+
 
 ## Using card10 in USB storage mode