updated readme

README.md

@@ -1,11 +1,30 @@
 # Simon game with Pro Mini
 
-Fun little project that has grown quite more than expected, at least on the
-hardware side.
+There is not much documentation for this project because I made exactly one 
+copy of the hardware and it'll probably end there. But if anyone tries to 
+replicate this, here are some hints:
 
-There will be a proper log for this later, with schematics etc. 
-(update, 3 months later: or maybe not)
+## Parts
 
-For now, you can have a peek and thank heavens you don't have to understand
-any of it xD
+- powered by 4 AA batteries (3 would be enough)
+- buck module to 4V, EN pin controlled by microcontroller 
+  (and a button through resistor, mcu senses button for soft shutdown etc).
+  Those modules can be found on aliexpress. For a replacement, you can just put
+  a mosfet there or something, as long as V_sup won't go over 5V.
+- arduino pro mini (anything with atmega328p will work)
+- 4 neopixels - blinky lights (chained)
+- dual 7-seg display unit for score, CC or CA doesn't matter, easy to reverse in code
+- 4 buttons or TTP223 touch keys for user input
+- 1 photo-transistor and some resistors for ambient light sense
+- displays driven by 595 or equivalent (eg 74HC4094)
 
+what to connect to where can be found in `pinout.h`.
+
+I'll send a more detailed schematic on request, if I still find my notes.
+
+## Flashing
+
+The firmware can be flashed using the arduino bootloader (via the makefile),
+but that produces a 1s delay on startup when the bootloader waits.
+For this reason I've wiped the bootloader and flashed it directly 
+with AVR Dragon using ISP programming.