Editing ErgoDox (section)

===Electronics===
The controller is based on a [[Teensy|Teensy 2.0]] AVR microcontroller board in the right half, with an I/O expander in the left half. The halves are connected with a 4-lead cable with power and [[I²C]] lines to the I/O expander.

A mini-[[USB]] port is supposed to be soldered on the right PCB and the Teensy board connected to the PCB with both pins and an internal mini-USB cable with cables soldered to the mainboard. Alternatively, a mini-USB cable can be connected directly to the Teensy board if there is a wire between the Teensy's "VCC" pin and "5V" on the main board, or the I/O expander gets its power from elsewhere.

The PCB design is reversible: the same type of PCB is used for both the left and right side. This means that it is possible to reverse the positions of the Teensy and the I/O expander, but then they would have to be mounted upside-down. Jumpers on the top of the PCB are also used.

The [[Cherry MX]] switches can be PCB-mounted, or be plate-mounted if a mounting plate is used (which they are in the official case designs). There is a diode for each switch, that can be either surface-mounted, through-hole, or through-hole, mounted inside most switches.

The diodes are supposed to be facing the other way on the left keyboard half, but the direction could also be swapped in the official firmware by flipping the values of <code>DRIVE_ROWS</code> and <code>DRIVE_COLUMNS</code> in <code>options.h</code>. See the [http://link.massdrop.com/51052a5521e070dffadc35145216439e7332c1f9330000f5/UR13ByuoATIlk-ogBaa1c discussion on the Ergodox assembly page].

Component list below (adapted from [https://ergodox.input.club/Hardware.html ErgoDox.org]):
{| class="wikitable"
|-
|2
|ErgoDox PCB
|-
|1
|[[Teensy]] USB Board, Version 2.0
|-
|1
|MCP23018-E/SP I/O expander
|-
|76-80
|[[Cherry MX]] switches, PCB or plate-mounted
|-
|76-80
|1N4148 diodes, SOD-123 package or DO-35 (0.3" pitch)
|-
|2
|2.2 kΩ resistors (red, red, red)
|-
|3
|3mm T1 LEDs
|-
|3
|~220 Ω resistors, or match to LED. (red, red, brown)
|-
|5
|Short jumpers
|-
|1
|0.1 µF ceramic capacitor (marked "104" for 10*10<sup>4</sup> picofarad). Not strictly necessary
|-
|1
|USB mini B connector WM17115.¹
|-
|1
|USB mini B plug with short cable (such as H2955).¹
|-
|1
|USB cable male A to male mini B.¹
|-
|2
|3.5 mm [[TRRS]] sockets, CP-43514. FC68129 will also work if its extra pins are snipped off.²
|-
|1
|Cable with two 3.5 mm [[TRRS]] plugs.²
|-
|}

Notes:

1. The USB cable could also be routed directly to the Teensy 2.0. On early revisions of the PCB (Massdrop), an additional wire would also have to be connected from Teensy pin VCC to the pad marked "5V" near the plug's position. The latest revision of the PCB would not require an additional wire.

2. FC68129 has been confirmed to work. A fixed cable could also be used instead of TRRS cable and plugs. Builders have also used other types of connectors.