Update Readme for the pocket-cape; Add schematic image.

pcb/README.md

@@ -7,9 +7,16 @@ PCBs :)
  * [Laser driver](./laser-drive): fast current source to drive Lasers. Often,
    the Lasers you can buy come with their own driver, but they are very slow.
    This one is meant to switch >= 1Mhz while behaving as a current source.
  * [Beaglebone cape](./cape): work-in-progress: a cape for the
  * [Beaglebone cape](./cape): a cape for the
    Beaglebone Black or Green providing all the connections to various
    parts of the set-up.
    parts of the set-up. This was the first version mostly for experimenting
    and successfully used.
  * [PocketCape](./pocket-cape): The new cape, ready for the cheaper
    and smaller PocketBeagle.
    Unlike the experimental board that used a DC/DC converter and stepmotor
    driver as separate modules, this has everything on-board.
    It is ready for double-sided boards with two outputs for lasers, polygon
    mirrors and two inputs for horizontal sync detection.

In the current set-up, they are mounted externally to provide easy access for
measuring various aspects. After the dust settles, they will all fit in the

pcb/pocket-cape/README.md

@@ -1,8 +1,30 @@
Work in progress, nothing to see here yet.
PocketBeagle LDGraphy cape
==========================

A cape for the PocketBeagle, that will allow to expose double-sided boards
(inside a yet to design case for a double-sided LDGraphy).
A cape for the PocketBeagle, that will allow to expose double-sided boards.

*Work in progress; won't yet work with the current software and case.*

Not only the software is not adapted yet, but this assume as motor
the 28BYJ-48, yet the acrylic case is still using the larger stepper.

So if you want to build something now, I suggest to use
the [experimental cape](../cape).

The board is packed with connectors; all of which are choosen in a way
that it very hard to connect to the wrong one:

| Designator | Type          | Description
|-----------:|:--------------|:---------------------
| J2         | 2p JST-XH     | Supply voltage. 12-16V
| J5, J8     | 3p JST-PH     | Laser1, Laser2 output
| J1, J3     | 2p JST-PH     | Laser1, Laser2 sync input
| J6, J7     | 5p 0.1" header| Polygon1, Polygon2 mirror
| J4         | 5p JST-XH     | Sled stepper 28BYJ-48
| J10        | 8p FFC 0.5mm  | Connector for 320x200 SPI display
| J9         | 4p JST-PH     | User-interface buttons
| J11        | USB           | USB connector for Wifi dongle

![](../../img/pocket-cape-render.jpg)
![](../../img/pocket-cape-schem.png)
![](../../img/pocket-cape.jpg)