Add description of the week

docs/group_assignments/group2/assignment4.md

@@ -13,7 +13,15 @@ authors:
 
 # Group work for week 4
 
-##
+In this group assignment, we learned about different tools for embedded programming.
+
+We first soldered microcontrollers (XIAO RP2040, XIAO ESP32C3, and XIAO SAMD21 with pin connectors. Then, we were smoothly able to plug it into the breadboard for a group assignment with ring oscillators.
+
+We first load the program into microcontrollers. We used programs given by our instructor. Detailed steps of this process could be found in our individual documentation for this week.
+
+We used Keysight InfiniiVision DSOX3102A, a digital storage oscilloscope.
+
+## Measurements 
 
 ![oscilloscope measurement](./assets/assignment4/oscilloscope/RP2040.png)
 
@@ -21,6 +29,8 @@ authors:
 
 ![oscilloscope measurement](./assets/assignment4/oscilloscope/SAMD21.png)
 
+## Schematics
+
 [rp2040 schematic](https://files.seeedstudio.com/wiki/XIAO-RP2040/res/rp2040_datasheet.pdf)
 
 [esp32C3 schematic](https://files.seeedstudio.com/wiki/XIAO_WiFi/Resources/Seeeduino-XIAO-ESP32C3-SCH.pdf)