This is an open standard for PCB edge connector pinning of various interfaces. It uses the AVX Corporation 009159010061916 connector which is low cost, high density and most importantly needs no soldering and is not permanently attached to a PCB.
A lot of effort is lost on documenting the pinout of connectors while prototyping as well as fiddling with zumper wire connectors. This project is an effort to reduce that effort as most interfaces are pretty well defined already.
For a motivating example see the edgy boards project or think of a decomposed circuit prototype with defined interfaces between the compoinents such as 
.
In order to uniquely identify which standard an edge connector adhears to it is suggested to use the foillowing naming convention: [organization letter code].[interface number code].v[optional subversion]
example osf.012.v0.1
Rational for this scheme is that there is minimal space on the PCB yet each interface should be uniquely identified. In order for other organizations or hobbiests to make their own extentions the organization identification is needed.
There are two seperate footprints for host/device side. For many interfaces it is clear which is which. Small arows on the top silkscreen help visually identify which side is host and which is device. Host connectors are usually placed on the right side of the board and device side connectors on the left.
In order to allow for standard 13mm wide adapter boards connectors should be placed no closer than 16mm apeart on a board edge (measured pin 1 to pin 1).
Pin 1 should always be on the top side of the board, this will make reverse connections less common.
Host connectors should generally be oriented on the right or bottom side of a board and device connectors on the left or top.
Connectors can be organized in a higherarchy where more specialized can be connected to less specialized if only a reduced function is required.
graph LR
root[GND on pin 1] --> vcc[5v on pin 10]
root --> j022[022 battery cells]
vcc --> j000[000 5v on 10, 3.3v on 9]
vcc --> j008[008 USB]
j000 --> j100[100 generic digital interface]
j000 --> j003[003 low voltage power]
j000 --> j004[004 BASE-T center taps]
j000 --> j006[006 RMII]
j000 --> j015[015 RGMII]
j000 --> j016[016 SGMII]
j000 --> j007[007 ADC]
j100 --> j011[011 GPIO]
j000 --> j013[013 PoE Rectified]
j000 --> j014[014 PoE Controlled]
j000 --> j017[017 BASE-T1]
j000 --> j018[018 QSPI]
j000 --> j019[019 100BASE-T with CT]
j019 --> j020[020 1000BASE-T with CT]
j100 --> j021[021 single IO UNIO]
j100 --> j001[001 I2C]
j100 --> j002[002 SPI]
j100 --> j005[005 1-wire]
j100 --> j010[010 UART]
j100 --> j012[012 CAN]
j009[009 ethernet cable side]
click j001 "https://github.com/skunkforce/put_on_edge/blob/master/001_I2C/README.md"
click j002 "https://github.com/skunkforce/put_on_edge/blob/master/002_SPI/README.md"
click j003 "https://github.com/skunkforce/put_on_edge/blob/master/003_power/README.md"
click j004 "https://github.com/skunkforce/put_on_edge/blob/master/004_BASE-T_CT/README.md"
click j005 "https://github.com/skunkforce/put_on_edge/blob/master/005_1wire/README.md"
| Pin | Description | typical connection |
|---|---|---|
| 1 | GND | |
| 2 | host out | tx or bidirectional data |
| 3 | host in | rx |
| 4 | host out | clk |
| 5 | host in | INT |
| 6 | host out | CS |
| 7 | host in | status |
| 8 | host out | ~reset |
| 9 | 3.3V | |
| 10 | 5V |
Many modern microcontrollers have either IO-pin-mux functionality or generic configurable state machine engines which allow multiple digital interfaces to be supported by the same set of pins. For a RP2040 for example an set of IO pins connected to an SPI connector would be over constrained. Using a generic 100 specification allows all the children to be connected.
Galvanic isolation modules (such and the iCoupler series) can support many different interfaces with one generic isolator. Care should be taken to standardize the interface such that a generic isolation device can be used for several different interface (SPI and UART for example).