Man/FAQ.md

@@ -2,7 +2,16 @@
 
 <br />
 
-## The data trace results are empty
+## Why does the node ID on the platform Tmote not match with the observer ID?
+
+There are two possible reasons why this could happen:
+- Binary patching failed for some reason, e.g. because the uploaded execute is not an elf file or the symbol `FLOCKLAB_NODE_ID` does not exist in the binary.
+- You are trying to read the node ID from the EEPROM on the Tmote. The ID stored in the EEPROM can be overwritten by the users and is therefore not reliable. If you still want to use this method, you either need to do the mapping by yourself. You could first read the current IDs, do the mapping and then in a second test write the desired node IDs (e.g. [Contiki](http://contiki.sourceforge.net/docs/2.6/a01425_source.html) provides a function to write the EEPROM).
+
+
+<br />
+
+## Why are the data trace results empty?
 There are several possible reasons why the data trace results could be empty:
 - Clock speed mismatch: make sure that the frequency specified in the `cpuSpeed` field of the `<debugConf>` matches the actual speed of the target CPU (master clock / SYSCLK). 
 - Invalid SWO pin config: ensure that the SWO pin is configured in SWO mode and isn't used otherwise in your target code.