diff --git a/avr/devices/n28/README b/avr/devices/n28/README
index 168aed4..e8fc361 100644
--- a/avr/devices/n28/README
+++ b/avr/devices/n28/README
@@ -4,7 +4,9 @@ N28
 
 - Role: Door sensor with temp sensor
 - MCU: AtTiny84
+- Frequency: 1MHz
 - Connection: RJ45
+- COM: COM2W
 - Predecessor: N21, N16
 - Periphery:
   - door sensor (TCRT1000)
diff --git a/avr/devices/n29/README b/avr/devices/n29/README
index e5dacce..9bfc439 100644
--- a/avr/devices/n29/README
+++ b/avr/devices/n29/README
@@ -4,7 +4,9 @@ N29
 
 - Role: Air quality and climate sensors
 - MCU: AtTiny84
+- Frequency: 1MHz
 - Connection: RJ45
+- COM: COM2W
 - Predecessor: N27, N24, N23, N19
 - Periphery:
   - PIR sensor (AMN31112)
diff --git a/avr/devices/n30/README b/avr/devices/n30/README
index cbfb5e9..d04b0b9 100644
--- a/avr/devices/n30/README
+++ b/avr/devices/n30/README
@@ -1,12 +1,13 @@
 
-N25
+N30
 ===
 
 - Role: LED strip controller
 - MCU: AtTiny84
+- Frequency: 8MHz
 - Connection: RJ45
 - Predecessor: N22, N16
-- UART: uart_bitbang2
+- COM: COM2W
 - Periphery:
   - LED strip connection (SK6812)
   - OWI interface