Add button to instructions

README.md

@@ -86,9 +86,18 @@ Uploading new Software isn't complicated, but a few things need to be in place f
 3. Search for `Seeed` and select the `Seeed XIAO RP2040` board if it hasn't been selected already (if it doesn't show up you need to install the board manager, see above). Then select the port and click okay. If no port shows up (see picture) check your cable/connection:
    ![image-20230703171243588](images/board_selection.png)
 4. Click on the upload button: 
-    ![image-20230703171418658](/home/d0/modular/_fremd/rp2040-chord-vco/images/upload.png)
+    ![image-20230703171418658](images/rp2040-chord-vco/images/upload.png)
 5. After a moment the uploading should either be finished or a red error message should explain that something went wrong. If it worked you can unplug the Seeed Xiao now, if it errored you need to resolve the error.
 
+**Note:** If the upload does not work, try the following:
+
+1. Disconnect the Seeed XIAO RP2040 from the USB-C Cable
+2. Press and HOLD the tiny "Boot"-Button on the back of the Seeed XIAO RP2040 (a white "B" is printed next to it)
+3. Reconnect the Seeed XIAO RP2040 to the USB-C cable
+4. Try uploading again
+
+If this doesn't work, ask for help or look at [this guide](https://wiki.seeedstudio.com/XIAO-RP2040-with-Arduino/)
+
 
 ## Images
 
@@ -98,3 +107,4 @@ Uploading new Software isn't complicated, but a few things need to be in place f
 
 ![3D (iso)](documentation/image/RP2040-VCO-3D_top30deg.png)
 
+