Edge Collective

Mothbot Prototyping

Table of Contents

TODO

Background

Mothbot is based on the initial JeeNode design by JeeLabs.

It's similar to many 'minimal Arduino' designs. For example:

Burning a bootloader on a 328P using a 328P

Guide here

First Build of the Mothbot

parts.jpg

First Build Notes / Revision Ideas

KiCAD notes

Custom footprint as logo in KiCAD

Use the 'Bitmap to component converter' in the main KiCad window (the bitmappy-looking 'a' in the below screenshot) to convert a bitmap to a footprint. Then you can import this footprint directly to the PCB layout (no need to have an associated symbol), as a logo.

parts.jpg
Screenshot highlighting the 'bitmap to component converter'

Design Rules / Templates for OSHPark

This guide has some nice info.

Reference for QWIIC connector

parts.jpg
Sparkfun 'QWIIC' I2C Connector
parts.jpg
Sparkfun 'QWIIC' I2C Connector

Sparkfun QWIIC reference

JST SH 4 Pin Connector

Adafruit reference for JST SH 4 Pin QWIIC Pin Ordering

Adding a reset button

parts.jpg
Footprint for KMR2 pushbutton

Adding a DC-DC converter footprint

TSR12450 Converter -- 5V output

TSR12433 Converter -- 3.3V output

parts.jpg
Pinout for DC-DC
parts.jpg
Footprint for DC-DC

Misc Notes

Aside on STM32

Nice note on STM32 boards from Jeenode, by the way.

Installing Arduino Libraries

Adafruit tutorail on installing Arduino libraries here.


Sensor notes

HC-SR04

Adafruit page

SHT10

Adafruit page

AM2315

Adafruit library


Mothbot Version 1.0 Notes

Made explicit i2c header that will allow for display. But this means that certain i2c sensors are no longer useful via screw terminal. But, added a 'qwiic' connector for i2c ... so maybe what we do is to make a qwiic adapter for AM2315 (i2c version).

Might need to change screw terminal size to 5mm, as they're far easier to source, it seems ...

Consider placing mounting holes at proper separation for 3XAA battery holder mounting holes ...


Mothbot Version 2.0 Notes

  1. Need bigger spacing on MCP1700 footprint
  2. Need C1 & R1 to be 0.1 uF and 10K (as they are), apparently, for bootloader to auto-reset properly (timing issue?)
  3. Note: I cannibalized C1 from a ver 1.0 Mothbot, need to replace!
  4. Reset button doesn't seem to work?
  5. Swapped A4 & A5 (they are SDA and SCL, not SCL and SDA, respectively) -- need to fix in order for monitor to work
  6. Add 0.1" headers for all terminals, as per i2c ... space as per breadboard?
  7. Match mounting hole spacing to battery pack?
  8. Nice note on measuring the battery level without draining it.

Mothbot Version 3.0 Notes

parts.jpg
First stab at version 3.
parts.jpg
3D Render of Final for Verison 3.
parts.jpg
Final of version 3, as submitted to OSHPARK. Board design files are here

Update (13 OCT 2020): Version 3 passed the following tests:

figA2
Minimal version of the Mothbot version 3.
figA2
Mothbot Version 3 seems to work! See the Mothbot Version 3 initial build video.

Things to change:

Notes on Display

So, maybe we switch over to 'GND VCC SCL SDA' in general, move pins to above U3.

Mothbot Version 3 Parts List / BOM

Some of the parts list on Amazon:

Aside: some of the Mothbot parts via Amazon:

Also:

Update 14 OCT 2020:

figA2
Sands Fish's build of the Mothbot!

Misc

Using Electron to talk to serial port:

Work Log


Oct 24 2020

Created dimensions document for Mothbot ver 0.1, here.


NOV 16 2020

Photo of latest version in action here: