Merge pull request #293 from microbit-foundation/test-points

Add test point map

Author: microbit-mark

hardware/assets/microbit-v2-assembly-back.png

@@ -150,7 +150,38 @@ The specific dimensions of the board are:
 
 The following image of the <span class="V2">V2</span> revision is taken from the [micro:bit V2 assembly diagram](/docs/hardware/assets/Microbit_V2_Assembly.pdf) provided by Avid.
 
-![micro:bit assembly](/docs/hardware/assets/microbit-v2-assembly.png)
+![micro:bit assembly front](/docs/hardware/assets/microbit-v2-assembly-front.png)
+
+The rear view of the device has been adapted to highlight the test points and describe their purpose.
+
+![micro:bit assembly back](/docs/hardware/assets/microbit-v2-assembly-back.png)
+
+### Exposed Test Points
+
+Test Point | Purpose
+---------- | -------
+TP1 | U5 Bootmode - [used to enter the ROM bootloader on the KL27Z](../../software/daplink-interface/#updating-the-daplink-full-image)
+TP7 | USB D+
+TP8 | USB D-
+TP17 | Access to Pin 1 on Battery connector
+TP19 | Access to VBUS line on USB Connector
+TP20 | Access for debugging internal I2C bus - SCL
+TP21 | Access for debugging internal I2C bus - SCL
+TP9 | VREG - [Actually the power rounded rectangular pad](../../accessories/making-accessories/#battery-pads)
+TP10 | GND - [Actually the GND rounded rectangular pad](../../accessories/making-accessories/#battery-pads)
+ 
+### Covered test points (Solder mask to be removed to access test point)
+
+Test Point | Purpose
+---------- | -------
+TP11 | U2_SWDCLK - used to debug nRF52833
+TP12 | U2_SWDIO - used to debug nRF52833
+TP4 | U5_SWD_DIO - used for debugging KL27Z
+TP3 | U5_SWD_TCLK - used for debugging KL27Z
+TP2 | U5_IF_NRST - used for debugging KL27Z
+TP6 | GND
+TP18 | VBUS
+TP5 | VREG - additional VREG, this is connected to TP9
 
 ## Further information