feat: add photos to readme

README.md

@@ -6,6 +6,9 @@ The LEDs are WS2812-compatible bulb-shaped LEDs, and they are controlled by an E
 
 This is a work in progress (2nd half 2024) project; documentation will be updated as the project progresses.
 
+![The finished map shown from the front](images/spaceapimap_front.jpg)
+![The finished map shown from the back, showing the wiring](images/spaceapimap_back.jpg)
+
 ## Contents of This Repository
 
 ### erfamap-output/
@@ -92,11 +95,38 @@ Usage:
 ## Components
 
 - WS2812-compatible 5mm bulb LEDs: https://de.aliexpress.com/item/1005005003701575.html
+  > :warning: **The vendor appears to sells LEDs with different pinouts as the same product!**
+  > 
+  > I recommend you order the LEDs before you order the PCBs so that you can make changes to the PCB if you receive a different pinout.
+  > The PCB design in this repo assumes the following LED pin order (starting from the flat side): `Dout`, `GND`, `5V`, `Din`.
 - Black 5mm LED sockets: https://de.aliexpress.com/item/1005005062684329.html
 - ESP32-C3 Super Mini: https://de.aliexpress.com/item/1005006252882434.html
 - JST-ZH cables: https://de.aliexpress.com/item/1005007298855435.html (4P, Reversed)
   - I recommend you order a mix of 100mm, 200mm and 300mm cables, as you'll be facing a variety of distances, and having shorter cables available makes for much easier troubleshooting.
   - In my order, roughly 10% of the cables had a broken wire.  Not sure whether I just got a bad batch, or whether they are just bad quality in general, but I recommend you keep that in mind when ordering.
+  - Don't rely on the order of colors in the product description.  I've ordered different batches, and got differently color orders each time.
+
+
+## Additional Features
+
+### Enter Config Mode on Reset
+
+- Solder a button or pin header between pins D5 and D6 on the ESP32-C3 Super Mini.
+  - These are the two pins closest to the USB port on the "unused" side of the ESP board.
+- Press and hold the button or short the pin header with a jumper while you press the reset button.
+- The ESP32 will now boot into WiFi config AP mode, where you can change the WiFi credentials and some additional parameters.
+  - If the configured WiFi can't be found, the ESP32 will automatically boot into config AP mode.
+
+### Automatic Brightness Adaption
+
+- You can plug a voltage divider with a photo resistor into the `IN` pin header on the PCB with the ESP32 on it, with the voltage divider's center tap connected to the `Din` pin.
+- You can use this to both adapt the LED brightness to the ambient light, and to turn off the LEDs below a certain ambient light level.
+- The thresholds can be configured via the web interface in config AP mode (see above).
+  - Note that the brightness sensor readings are reversed: High values correspond to darker ambient light levels.
+
+![Schematic of the voltage divider setup](images/brightness_sensor_schematic.png)
+![Photo of a rather messy actual implementation](images/brightness_sensor.jpg)
+
 
 ## License
 
@@ -104,9 +134,9 @@ Unless otherwise noted, the contents of this repository are licensed under the M
 
 ### Public Domain Data
 
-I consider the contents of `erfamap-output/` and `esp32/src/spacemap.h` to be in the public domain.
+To the best of my knowledge, the contents of `erfamap-output/` and `esp32/src/spacemap.h` are not protectable by copyright and are therefore in the public domain.
 
-If they are not, I license these under the Creative Commons [CC0 1.0][cc0] "No Rights Reserved" license.
+In case I do have copyright claims on them, I license these under the Creative Commons [CC0 1.0][cc0] "No Rights Reserved" license.