diff --git a/ntnu/21v/tfe4130/lectures/2021-01-14/2021-01-14.md b/ntnu/21v/tfe4130/lectures/2021-01-14/2021-01-14.md
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+++ b/ntnu/21v/tfe4130/lectures/2021-01-14/2021-01-14.md
@@ -0,0 +1,24 @@
+---
+layout: layouts/lecture
+title: "TFE4130"
+description: "1D Bølger forts."
+date: "2021-01-14"
+math: true
+---
+
+## Akustisk impedanse
+
+## Akustisk intensitet
+
+$$ \boldsymbol{I} = \frac{1}{T}\int_0^T p_\text{real}\boldsymbol{v}_\text{real}(t) dt $$
+
+FOr en planbølge
+
+$$ I_x = \frac{p_\text{rms}}{p_x c}$$
+
+## Refleksjon og transmisjon
+
+Dersom en børge beveger seg over en grenseflate mellom to forskjellige impedanser.
+
+* Trykket nå være kontinuerlig over grenseflaten
+* Farten over grenseflaten må være konstant.
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diff --git a/ntnu/21v/tfe4130/tfe4130.md b/ntnu/21v/tfe4130/tfe4130.md
index 6e0a996..3ce83ad 100644
--- a/ntnu/21v/tfe4130/tfe4130.md
+++ b/ntnu/21v/tfe4130/tfe4130.md
@@ -4,6 +4,12 @@ title: "TFE4130"
 description: "Bølgeforplantning"
 ---
 
+## Filer og annet
+
+Alle øvinger og andre viktige filer ligger på [git](https://git.glados.no/oyvindskaaden/TFE4130).
+
 ## Forelesninger
 
-[2021-01-12](./lectures/2021-01-12/) - Intro
\ No newline at end of file
+[2021-01-12](./lectures/2021-01-12/) - Intro
+
+[2021-01-14](./lectures/2021-01-14/) - Bølger forts.
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diff --git a/ntnu/21v/ttt4280/lab/1/1.md b/ntnu/21v/ttt4280/lab/1/1.md
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+++ b/ntnu/21v/ttt4280/lab/1/1.md
@@ -0,0 +1,34 @@
+---
+layout: layouts/lecture
+title: "TTT4280"
+description: "Labforelesning 1"
+date: "2021-01-18"
+math: false
+---
+
+## Laboratorium
+
+### System
+
+* Raspberry Pi
+* Linux
+* A/D omformere
+* Python
+
+### Oppgaver
+
+* Systemoppsett
+  * Klargjøre rPi og instrumenteringskrets
+* Akustikk
+  * Beregne retning til lydkilde
+* Radar
+  * Doppler
+* Optikk
+
+## Laboppgave 1
+
+1. Tegne blokkdiagram
+2. Studere datablat for ADC
+3. Drøfte fordeler med DMA
+
+![Blokk](figures/TTT4280%20-%20Lab%20Blokk.png)
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diff --git a/ntnu/21v/ttt4280/lab/1/figures/TTT4280 - Lab Blokk.png b/ntnu/21v/ttt4280/lab/1/figures/TTT4280 - Lab Blokk.png
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index 0000000..799742d
Binary files /dev/null and b/ntnu/21v/ttt4280/lab/1/figures/TTT4280 - Lab Blokk.png differ
diff --git a/ntnu/21v/ttt4280/lectures/2021-01-18/2021-01-18.md b/ntnu/21v/ttt4280/lectures/2021-01-18/2021-01-18.md
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+++ b/ntnu/21v/ttt4280/lectures/2021-01-18/2021-01-18.md
@@ -0,0 +1,8 @@
+---
+layout: layouts/lecture
+title: "TTT4280"
+description: "Usikkerhet og feilforplantning"
+date: "2021-01-18"
+math: true
+---
+
diff --git a/ntnu/21v/ttt4280/ttt4280.md b/ntnu/21v/ttt4280/ttt4280.md
index dc2877e..896f771 100644
--- a/ntnu/21v/ttt4280/ttt4280.md
+++ b/ntnu/21v/ttt4280/ttt4280.md
@@ -8,3 +8,5 @@ description: "Sensorer og instrumentering"
 
 [2021-01-11](./lectures/2021-01-11/) - Intro og målesikkerhet
 
+[2021-01-18](./lectures/2021-01-18/) - Usikkerhet og feilforplantning
+