A Software Guy Does Hardware

From idea to finished product

By Andrew Lindsay at Reading Geek Night 09/07/2013@AndrewDLindsay

About meStarted programming Sinclair ZX80 as a kidSoftware developer for over 25 years, now freelance.Experience of TV, Government, Telecoms, ISP, Transport,

Utilities and Finance.Instrumentation and Embedded Systems RolesJava, C, C++, Basic, Pascal, web etc…Interest in microcontrollers re-ignited with ArduinoThen mbed and ARM processorsRegular at IoT London meetups

The ideaIoT London Meetup number 9, June 2012Vodafone demonstrating K3370 Mobile broadband

dongle and mbed connected to printer to display smsAlready used Arduino with multiple LED Matrix displays

to create network enabled scrolling displayFamiliar with mbed technology

Prototype

Beyond a prototypeDesign own PCBLearn EagleCAD for schematic and PCB layoutGenerate gerber filesHave small batch of PCBs manufacturedUsed Seeedstudio Fusion PCB service

Schematic

PCB Design

Creating output

Checking PCB - WebGerber

Manufacture

Boards arrive from China

Building the board #1

Building the board #2

Completed Board

SMS Display

UsesIntegrate with services that send SMS, e.g. IFTTTDisplay Foursquare checkins, weather alerts, Google

calendar events.Rude messages from friendsAdd small thermal printer for hard copy outputReact to commands, e.g. Balance check.Other USB devices, e.g. Bluetooth can be used

ImprovementsReposition dongle to outside of boardOr provide a cutout so USB socket is at correct angle and

copper pour is not shielding dongleUse alternative USB socket footprint with plated

mounting holesAdd sound notification of new messages Silkscreen updates and correctionsAdd logos for open hardware and publish CAD files

Thank you

Featured sitesmbed.org – Prototype platformmbed.org/handbook/Vodafone – Mobile donglewww.meetup.com/iotlondon - IoT London Meetupwww.cadsoftusa.com – Supplier of PCB design toolsmayhewlabs.com/webGerber – 3D gerber viewerwww.seeedstudio.com – Fusion PCB serviceifttt.com – Making the internet do thingsblog.thiseldo.co.uk/?p=703 – my blog with more info