adds enclosure 2

README.md

@@ -5,9 +5,10 @@ See a [video](https://youtu.be/2fTZVQPiG7E) of the device in action.
 
 ![logo](SSoS180x90.png)
 
-![SSoS for LEGO](enclosure/assembled-cable.jpg)
+![SSoS for LEGO](enclosure2/product-cable.jpg)
+
+![Connected to the hub](enclosure2/product-hub.jpg)
 
-![Connected to the hub](enclosure/assembled-mounted.jpg)
 
 ## Introduction
 I stumbled on this module [Seven Segment for micro:bit](http://www.monkmakes.com/mb_7_seg.html).
@@ -40,7 +41,7 @@ First some proof of concept sketches (using SFRs for ports, timer, ISR), finally
 
 
 ## User manual
-There is an extensive [user manual](manual) with examples (as implemented by the firmware for the [end-product](firmware/SSoS)).
+There is an extensive [user manual](manual) with examples (as implemented by the [firmware](firmware/SSoS)).
 
 
 ## LEGO enclosure 
@@ -50,10 +51,13 @@ I 3D-printed an [enclosure](enclosure) so that I can use SSoS with LEGO Mindstor
 ## LEGO demo
 See the [LEGO code](legocode) for some examples of how to use the SSoS device with LEGO.
 
-## Smaller
-The (LEGO) enclosure is 4×8 LEGO units (studs). But LEGO technic components need to have odd length.
-So I set out to miniaturize the Seven Segment over Serial, making a Seven Segment over Serial Small (SSoSS).
+## Generation 2: Seven Segment over Serial Small
+The (LEGO) enclosure we made is 4×8 LEGO units (studs). But LEGO Technic components usually have an _odd_ length.
+So I set out to miniaturize making a Seven Segment over Serial _Small_ (SSoSS).
 Target is 3×7. To achieve this, I made a single PCB, containing both the "Nano" and the 7-segment units.
-Section [version 2](electronics2) shows the schematics and the unexpected flashing problems.
+
+Section [electronics2](electronics2) shows the schematics and the unexpected firmware flashing problems.
+
+Section [enclosure2](enclosure2) shows the new enclosure.
 
 (end)

electronics2/readme.md

@@ -1,4 +1,4 @@
-# Electronics - version 2
+# Electronics - version 2 (small)
 
 Seven-Segment over Serial: a device consisting of four 7-segment display units, 
 controllable via a serial link, to be usable as display for LEGO Mindstorms Robot Inventor or Spike Prime.

enclosure2/readme.md

@@ -0,0 +1,121 @@
+# Enclosure version 2 (small)
+
+I made an enclosure (case) for the _Seven-Segment over Serial Small_ device.
+
+I designed the enclosure in [Fusion 360](https://www.autodesk.eu/products/fusion-360), 
+and printed it on my [Cetus3D](https://shop.tiertime.com/product/cetus-3d-printer-mk3/).
+
+I made one key design decision: the PCB has a friction-fit in the enclosure. 
+That is the plan: no screw, no glue, maybe a bit of click.
+
+[JLCPCB](https://jlcpcb.com/DMP) offered me to try their 3D-printing services, which is gladly accepted.
+
+
+## 3D modeling 
+
+I started by modelling the PCB with some key components.
+
+![PCB top](PCB-top.png)
+
+![PCB bottom](PCB-bottom.png)
+
+
+Here is the PCB, but now in its enclosure.
+
+![Product top](prod-top.png)
+
+![Product bottom](prod-bottom.png)
+
+
+This is the enclosure in isolation.
+
+![Enclosure top](enclosure-top.png)
+
+![Enclosure bottom](enclosure-bottom.png)
+
+
+The final figures show a sectional view on the short and long side
+
+![Section short](section-short.png)
+
+![Section Long](section-long.png)
+
+
+## STL files
+
+Here is the STL file for the enclosure.
+It is a single [stl file](enclosure.stl)
+
+
+## 3D print results on Cetus3D
+
+![enclosure 1](enclosure1.jpg)
+
+![enclosure 2](enclosure2.jpg)
+
+![enclosure 3](enclosure3.jpg)
+
+![enclosure 4](enclosure4.jpg)
+
+
+
+## Electronics enclosed
+
+![product 1](product1.jpg)
+
+![product 2](product2.jpg)
+
+![product 3](product3.jpg)
+
+![product 4](product4.jpg)
+
+Finally, with cable and hub.
+
+![product with cable](product-cable.jpg)
+
+![product with hub](product-hub.jpg)
+
+
+## 3D print via JLCPCB
+
+[JLCPCB](https://jlcpcb.com/DMP) offers various 3D printing technologies:
+- **SLA (resin)**  
+  SLA or Stereolithography is an additive manufacturing process that belongs to the vat photopolymerization family. 
+  The vat contains photo sensitive (liquid) resin and a light source (e.g. laser) is used to cure (solidify) the resin 
+  ([youtube](https://www.youtube.com/watch?v=TuubPMWeQQE&t=143s)).
+  This method is popular because it produces high-accuracy parts with fine features and smooth surface.
+
+  JLCPCB offers 3 resins: LEDO 6060, 9000R and 8000. They are all white.
+  Also the lowest cost, my model is $1.
+
+  ![JLCPCB SLA](jlcpcb-sla.png)
+
+- **MJF (Nylon)**  
+  MJF or Multi Jet Fusion is an industrial 3D printing process that quickly produces nylon parts.
+  It uses an inkjet array to apply (fusing and detailing) "ink" across a bed of nylon powder, which are then fused with heat. 
+  The process repeats layer after layer ([youtube](https://www.youtube.com/watch?v=KKyQJLe_G6o)).
+
+  JLCPCB offers 2 nylons: PA12-HP (black or gray) or PAC-HP (multicolor).
+  The PA12-HP is still affordable ($3.64 for my model), but PAC-HP gets expensive ($23.64)
+
+  ![JLCPCB MJF](jlcpcb-mjf.png)
+
+- **SLM (metal)**  
+  SLM or Selective Laser Melting (aka DMLM or direct metal laser melting), is a method for a metal additive manufacturing technology.
+  It uses a bed of powder with a heat source to create metal parts ([youtube](https://www.youtube.com/watch?v=yiUUZxp7bLQ))
+
+  JLCPCB offers 1 material: 316L stainless steel. Higher price range: $23.56 for my model.
+
+  ![JLCPCB SLM](jlcpcb-slm.png)
+
+- **FDM (ABS)**  
+  FDM or Fused Deposition Modeling (or Fused Filament Fabrication) is the offical name for the well-known process used in hobby printers.
+  It works by depositing melted filament material (plastic wire from a spool) over a build platform 
+  layer by layer until you have a completed part ([youtube](https://www.youtube.com/watch?v=raSAhXb2ea4)).
+
+  JLCPCB offers 1 material: ABS in white and black. Moderate price point: $3.83.
+
+  ![JLCPCB FDM](jlcpcb-fdm.png)
+
+(end)
+