Here comes a list of stuff you might need in order to play with all this. Probably trivial stuff but it took me some time to figure out all the keywords, might be useful for people joining this field. I am a cheap bustard so nothing too fancy here.
For simplicy of troubleshooting I like to split the ECU hardware into two pieces - a board with just the CPU (brain board), and the input-output board, also known as main board.
discovery is an off the shelf brain board. rusEfi also has it's own brain board, both are the same thing
Main board is also known as "discovery shield" if you look at the main board as something which allows a discovery board to act like an ECU.
Mandatory items
#1 stm32f4discovery http://www.digikey.com/ part number 497-11455-ND
I/O hardware
![Image](http://rusefi.com/wiki/images/1/1c/Tindie-smalls.png)
You can go with a proven simple board Frankenstein
Or with trivial individual modules: analog inputs board & 6 channel low-side / 12 channel low-side
Optional useful stuff
I prefer to order these small random things from eBay. Most of these would cost around $3 shipped each, but it would take maybe 3 weeks to get them. Same stuff could be ordered from https://www.sparkfun.com/ - it would be more expensive, but you would get it way faster.
Prototyping board
![Image](http://rusefi.com/images/forum_posts/prototyping_board.jpg)
Breadboard
![Image](http://rusefi.com/images/forum_posts/breadboard.jpg)
Male to female jumper wire
![Image](http://rusefi.com/images/forum_posts/jumper_wire.jpg)
5mm led
![Image](http://rusefi.com/images/forum_posts/5mm_led.jpg)
2.54mm Single Row Right Angle Pin Header Strip
![Image](http://rusefi.com/images/forum_posts/single_row_angle_header.jpg)
2.54mm Single Row Pin Header Strip
![Image](http://rusefi.com/images/forum_posts/single_row_header.jpg)
1N4001 Diode
![Image](http://rusefi.com/images/forum_posts/1N4001_diode%20.jpg)
10x2 double row female header
64p ECU connector (if applicable) http://www.ebay.com/itm/121122884285
optional but useful stuff:
Saleae 24MHz 8Channel Logic Analyzer - somehow these cost under $15 on http://www.aliexpress.com I do not know if they are fake or what, but they work
When you have at least some of the hardware you can continue with getting the firmware into the board