diff --git a/content/06_electronics_design.md b/content/06_electronics_design.md
index 72817511f21c028d0662a36267fd244240217a17..b0bf970e8b6c5d02d646deb030eee88a2a23edaf 100644
--- a/content/06_electronics_design.md
+++ b/content/06_electronics_design.md
@@ -27,11 +27,11 @@ Drawing the traces was more challenging. It took me a few tries before I was abl
 
 When I started milling my design, it was obviously too large. Turns out the DPI of images exported by EAGLE on retina MacBooks ends up twice as high as claimed. Luckily this is easily fixed in mods by overriding the value embedded in the png.
 
-At this point I feel like a pro at stuffing. It went by pretty quickly and I'm happy with all my joints.
+At this point I feel comfortable stuffing boards. It went by pretty quickly and I'm happy with all the joints.
 
 ### Programming
 
-It had been a few years since I've flashed a microcontroller so I was uncertain how many issues I should expect to run into. Luckily things went pretty smoothly. I encountered a few "device not found" errors that were circumvented by unplugging and replugging the programmer and boards.
+It had been a few years since I've flashed a microcontroller so I was uncertain how many issues I should expect to run into. Luckily things went pretty smoothly. I encountered a few "device not found" errors that were circumvented by unplugging and replugging the programmer and boards. I just used Neil's [echo code](http://academy.cba.mit.edu/classes/embedded_programming/hello.ftdi.44.echo.c).
 
 ![](/img/06_pcb_plus_ftdi.jpg#c)
 
diff --git a/content/10_input_devices.md b/content/10_input_devices.md
index bb4a5d164a9f781831de192037bb13d3bae22e68..8648f8dba71410a29a2ef890083170317b4c57bc 100644
--- a/content/10_input_devices.md
+++ b/content/10_input_devices.md
@@ -133,5 +133,5 @@ This board's output looks a lot better than the previous one's.
 
 ![](/img/10_better_amplification.png)
 
-I decided to plug it into my audio interface so I could listen to the output directly. It [sounds](/audio/10_bass_test.mp3) just like the untreated output of my bass.
+I decided to plug it into my (commercial) audio interface so I could listen to the output directly. It [sounds](/audio/10_bass_test.mp3) just like the untreated output of my bass.
 
diff --git a/content/11_output_devices.md b/content/11_output_devices.md
index 9e3147de965ada087bba4f24cc3b9e64efd46dc1..b39a445b96650d2dc4095a4443bbc601d74b1bdb 100644
--- a/content/11_output_devices.md
+++ b/content/11_output_devices.md
@@ -7,7 +7,7 @@ weight = 12
 
 Files: [midi_test.c](https://gitlab.cba.mit.edu/erik/attiny44a_blink/blob/master/midi_test.c)
 
-This week we're exploring output devices. I need to send MIDI messages for my final project, so my goal for the week is to figure out this subsystem.
+This week we're exploring output devices. I need to send MIDI messages for my final project, so my goal for the week is to figure out this subsystem. (Edit: in the end I simplified things and didn't use MIDI for my final project.)
 
 
 ### Background
diff --git a/content/13_interfaces.md b/content/13_interfaces.md
index def1b3ae6b22f45e03329b6edc7255f9f5232869..e93266233abb6de13f055b2d58b298ac3533cd8b 100644
--- a/content/13_interfaces.md
+++ b/content/13_interfaces.md
@@ -5,7 +5,7 @@ menu = "main"
 weight = 14
 +++
 
-Files: [embedded](https://gitlab.cba.mit.edu/erik/attiny44a_blink) (see button_serial.c) [test_app](https://gitlab.cba.mit.edu/erik/serial_cpp) [shelf_app](https://gitlab.cba.mit.edu/erik/htmaa_shelves) (see shelf_button.cpp)
+Files: [embedded](https://gitlab.cba.mit.edu/erik/attiny44a_blink) (see button_serial.c) [serial_cpp](https://gitlab.cba.mit.edu/erik/serial_cpp) [shelf_app](https://gitlab.cba.mit.edu/erik/htmaa_shelves) (see shelf_button.cpp)
 
 
 This week we're diving deeper into communication between microcontrollers and computers.