correct logging

beginner/apps/Cargo.toml

@@ -34,12 +34,11 @@ opt-level = 3
 overflow-checks = false
 
 [features]
-# set defmt logging levels here
-default = [
-  "defmt-default",
-  # "dependency-a/defmt-trace",
-]
 
+default = [
+  "other-feature"
+]
+other-feature = []
 # do NOT modify these features
 defmt-default = []
 defmt-trace = []

boards/dk/Cargo.toml

@@ -18,11 +18,10 @@ defmt-rtt = "0.3.1"
 advanced = []
 beginner = []
 
-# set defmt logging levels here
 default = [
-  "defmt-info",
-  # "dependency-a/defmt-trace",
+  "other-feature"
 ]
+other-feature = []
 
 # do NOT modify these features
 defmt-default = []

embedded-workshop-book/src/using-hal.md

@@ -28,15 +28,10 @@ $ cargo doc -p dk --open
 
 ✅ Check the API docs of the `Led` abstraction. Change the `led` program, so that the bottom two LEDs are turned on, and the top two are turned off.
 
-🔎 If you want to see logs from Led API of the `dk` Hardware Abstraction Layer, go to `boards/dk/Cargo.toml` and change the log level of the `dk` crate:
+🔎 If you want to see logs from Led API of the `dk` Hardware Abstraction Layer, flash the dk with the following environment variable:
 
-```diff
-# set defmt logging levels here
-default = [
--  "defmt-debug",
-+  "defmt-trace",
-  # "dependency-a/defmt-trace",
-]
+```console
+$ DEFMT_LOG=trace cargo run --bin led
 ```
 
 Among the logs you'll find the line "I/O pins have been configured for digital output". At this point the electrical pins of the nRF52840 microcontroller have been configured to drive the 4 LEDs on the board.