Open Hardware Summit 2020 badge

Thanks to @Anool Mahidharia for adding many more 3-D models for parts in the design.  This has been merged:

https://github.com/oshwabadge2020/Badge-PCB/pull/10

And thanks to @greg davill for posting a video of how to STEP model to footprint.  He did with in minutes of me tweeting for help!

https://twitter.com/GregDavill/status/1215783134710493184

I was able to follow those directions to add the STEP model I found on Digi-Key:

Layout is currently happening in @Michael Welling repo:

https://github.com/mwelling/Badge-PCB

However, we don't currently have 3D models setup for most parts:

Any advice or help would be appreciated!

This is the BoM;

https://drive.google.com/file/d/18lHeGdCgqArWiu-SZ1YsWTnsnJjhUgXG/view?usp=sharing

Our tact switch in the BoM is E-Switch TL3305CF260QG (Digi-Key EG5355CT-ND).

https://www.digikey.de/products/en?keywords=EG5355CT-ND

This is the footprint being used in KiCad:

But the 3D model is:

but doesn't have same apperance as:

DigiKey does give a STEP file: http://stp-3d-models.e-switch.com/stp3dmodels/TL3305CFxxxxG.stp

@Andrew Sowa @Anool Mahidharia any advice on using the STEP file in KiCad?

Layout is currently happening in @Michael Welling repo:

https://github.com/mwelling/Badge-PCB

However, we don't currently have 3D models setup for most parts:

Any advice or help would be appreciated!

@Michael Welling has picked up the KiCad layout from @Alex Camilo and placed the components on the board.  Check out his fork:

https://github.com/mwelling/Badge-PCB

Here are screenshots.  The third button doesn't fit but I think it is OK to just have 2 buttons.

For context, here is the SVG outline that @Alex Camilo:

https://github.com/oshwabadge2020/Badge-PCB/blob/master/watch-pcb.svg

Adafruit just showed off CLUE on Ask An Engineer last night.  It is similar specs to this project and the layout is very nice:

The schematic and layout have been changed to use a MicroUSB connector:

Connector_USB:USB_Micro-B_Molex-105017-0001

I have uploaded a new schematic as an PDF attachment to this project.

@Alex Camilo is continuing to work on the layout in KiCad:

Here is the current BoM for the Open Hardware Summit wrist badge:

https://drive.google.com/file/d/18lHeGdCgqArWiu-SZ1YsWTnsnJjhUgXG/view?usp=sharing

Phil from Adafruit confirmed that the LCD connector is:

https://www.digikey.com/product-detail/en/5051102291/WM11288CT-ND/5313425/?itemSeq=294444169

@Alex Camilo has updated the board outline in KiCad:

https://github.com/oshwabadge2020/Badge-PCB/commit/b09d368ec7e4bed90f17c154e0ccf89697531676

From the project chat:

https://hackaday.io/messages/room/283874

Alex Camilo writes:

• instead of running the display through a cutout i think it's better to have the connector on the top.
• this way we can use an acrylic spacer and have all the components on the top of the bottom board.

• the acrylic spacer would be a 5mm (or 9mm) donut.
• we would use m2 threaded SMT standoffs soldered to the bottom pcb

https://www.digikey.com/product-detail/en/w-rth-elektronik/9774015243R/732-7069-1-ND/5320674

• the top PCB would be passive, with silk screened artwork on the top.
• the bottom would have components on one side.

There are two ways to do the straps:

the way the openHAK does it with a notch in the PCB outline covered by resistors

https://www.hackster.io/news/openhak-is-a-completely-open-source-fitness-tracker-launching-on-kickstarter-5c9cfda3e2bb

HACKSTER.IO

OpenHAK Is a Completely Open Source Fitness Tracker Launching on Kickstarter

A large portion of you are probably wearing a fitness tracker right now as you read this. They're a great way to collect data on your physical activity and ensure that you're getting regular exercise. But while basic fitness trackers are very affordable, you're almost always stuck with proprietary hardware and software.

Read this on Hackster.io

Alex Camilo9:41 PM

for a good look 

or, we just do a notch like this

https://www.cnx-software.com/wp-content/uploads/2016/03/ESP8266_Smartwatch_Large.jpg

CNX-SOFTWARE

• benefits of notch: single side load.

• then we get a strap like this and it covers the bottom (eBay link)

• the one with the resistors looks nicer but complicates things.

this decision won't affect layout too much so ill make it at the end when everything else is done. I am leaning toward notches.

Michael Welling writes:

• I think the straps are more cost effective
• it will also protect the skin from the PCB

This is the repo we are working from:
https://github.com/oshwabadge2020/Badge-PCB

Alex Camilo is the lead right now for schematic and layout with Michael Welling assisting.

Check out the GitHub issues for discussion like:

layout: single board or 2 stacked boards? #5

Ask to join this project then you can see our chat room:

https://hackaday.io/messages/room/283874

Project timeline in Google Sheets:

https://docs.google.com/spreadsheets/d/15aa3_ncIndz-62_U2ijDQ6RpO70SIm8lHh68fzNV_oc/edit?usp=sharing

Kevin at DigiKey has ordered quantity 300 of this display from Adafruit:
https://www.adafruit.com/product/4421

I believe Kevin will also be able to get quantity 300 of the Rigado BMD-340-A-R-00 module (which has Nordic 82540 microcontroller).

WORK IN PROGRESS NOTES

- Wrist form factor like Chaos Camp watch?

https://firmware.card10.badge.events.ccc.de/index.html

- SparkFun Artemis... software support not ready?  talk to Owen?

- lessons learned: must have USB

  - use a usb-to-serial? 

   - CP2102 https://www.digikey.com/product-detail/en/silicon-labs/CP2102-GMR/336-1160-1-ND/3672615

- discussion with Nate and Michael and Drew:

  - wristwatch with sparkfun artemis

  - GPS, vibration motor, small IPS LCD 

- supercon meeting

   - maybe not use artemis

   - wireless uC ideas: ESP32, Rigado... Nordic NRF52840

    - do we really need wireless?  if not, then STM32 or SAMD

    - Nordic NRF52840 is well supported by adafruit

- GPS useful?  not really since indoors... BLE beacons might be more practicle

- Idea: reuse the card10 design

- note: here is a way to use stock wristband watch stuff

https://www.youtube.com/watch?v=Uib8nUV1JEg&feature=youtu.be&t=2010

- wristband from sparkfun: https://www.sparkfun.com/products/11734

MUST HAVE:

- USB programmable (either builtin or usb-to-serial)

- Accel/IMU  6DoF of 3DoF

If throw on a 6dof e-compass we can get the magnetometer too: https://www.digikey.com/product-detail/en/stmicroelectronics/LSM303AGRTR/497-16527-1-ND/6006105

- Arduino library compatible

- Display LCD or OLED - source from Digi Key?  if from China, remember Chinese New Year

... or e-paper (Pervasive Display on DigiKey)

... flexible epaper?

- note: DOOM guy SAO has: High DPI ST7789 1.3" 240x240 LCD Screen

https://hackaday.io/project/164346-andxor-dc27-badge/log/165849-dc27-doom-sao-hurt-me-plenty

-  ST7789 1.3" 240x240 LCD  possible on DigiKey?

- V1.69bis standard SAO connector (have them on the wristband -- use flex?)

- POWER? 

   - LiPo from Sparkfun

    - note: card10 has 200mAh 

NICE TO HAVE:

- MicroPython or CircuitPython

   - note: Python may drain power on the NRF52840 (ask tannewt)

- BLE that works

SUMMARY: Nordic 82540 might be the best choice

There is a module from Rigado that Andy Sowa has used:

https://www.digikey.com/product-detail/en/u-blox-america-inc/BMD-340-A-R-00/672-BMD-340-A-R-00CT-ND/8638940

SOURCING CONCERNS:

- LCD 240x240

- Vibration motor

- watch strap / mount