Adventures in Engineering Trade-Offs

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Case Study: Cheap, High Volume Off-the-Shelf Hacker Parts Best Custom Hardware

Arduino Uno – Cheap and readily available.

Recently, a client came to me because they were having difficulty getting a $150 interface, associated housing and a further custom PCB.  The interface was used between the Ubuntu based controller and the hardware, except for the touch panel display.  The hardware consisted of a couple of payment systems, and some dispensing mechanisms, as well as a service switch.

After doing some research, I discovered that I could cover all the required functions using an Arduino Uno and a Grove shield. This combination cost an order of magnitude less than there old design.  Along with decreasing the overall cost of the Bill of Materials, the new components could be bought on an as needed basis, greatly reducing stocking expense.  Also, because the Arduino Uno is so popular, it it unlikely to go out of production any time soon.  Even if it does, the form factor lives on in a variety of more powerful designs.

As I like to point out, we now live in the golden age of prototyping and rapid product ramp up.  This is because there is such a wealth of incredibly powerful and cheap components that are available in large quantities, usually from China. This makes it easier than ever before to lash together a prototype, and then turn this into a early production run.  The early production run can then be used to validate a market and quickly cycle through user feedback iterations.   This all translates in to being able to build product momentum for a market leader.  Also, for me personally, it means I get to see my ideas get out into the world at breathtaking speed.  For this particular example, the whole redesign, including coding, documentation and acceptance testing, only took about 80 billable hours.

Grove Shield – Makes interfacing a snap.

 

 

Kickstarter – Rebooted

It’s taken a couple of years since my last successful Kickstarter to find another Kickstarter worthy idea.

I learned a lot about how the kickstarter marketing funnel works with

I also put up a “quick and dirty” support site at

http://rocketblueautomation.com/

Now, 2 years later, we are doing a second production run of the Pi Platter because it continues to sell consistently, and we have a few regular customers.

Mind you, the Pi Platter was never intended to be  a “home run,” but rather just a base hit so I could fully appreciate how crowd funding works.   Indeed, I learned a lot that will help me on this next “reboot.”

As of this writing, I am still refining the target market.   What is clear is that there is a market for a nice case, with a nice user interface and associated code.

ESP32

One of the things that made the last Kickstarter successful was we had some good examples about how to use our offering – namely the Pi Platter.

For most makers, a polished physical packaging is an afterthought – and often never gets done.  This has certainly been the case for me.   The user interface consists of a 64×64 oLED display and a rotary encoder with a built in push button switch.  So far, I wrote out  micropython script to make a temperature/humidity alarm  with adjustable set point.  The real time interrupts of the rotary encoder where a bit tricky and not surprisingly, micropython was a bit slow on an ESP32.   I was curious how well micropython worked, but now that I’ve seen the result, I will redo the code in C.  The case is large enough for any number of ESP32, ESP8266 and Arduino boards, including a LiPo battery and charge controller or boost converter.   Even a Raspberry Pi Zero will fit.

A couple of candidate niches to sell my new case/UI design to  small farm/homestead and the biohackers. I will likely create more than one Kickstarter to cover all the possibilities.

 

 

Pi Platter at the Denver Maker Faire

SSD booth at the Denver Maker Faire

SSD booth at the Denver Maker Faire

On Saturday, June 11, 2016 I had a chance to show off 5 of the Raspberry Pi designs I’ve been working on.

In preparation for a Kickstarter, I’ve been assembling designs that showcase the versatility and usefulness of the “Pi Platter” board I’ve been working on.  Dan Julio, the other engineer on the project, and I are both members of the Boulder Hackerspace aka Solid State Depot. The Boulder Hackerspace was invited to the Denver Mini Maker Faire at the Denver Musieum of Denver Museum of Nature and Science.

Introducing the Pi Platter Solar battery charger, USB and RTC board

Introducing the Pi Platter Solar battery charger, USB and RTC board

The Pi Platter board is designed to give the Raspberry Pi Zero, as well at the other models of the Raspberry Pi additional features such as

    1. Additional USB ports
    2. Solar Li battery charging circuit
    3. Real Time Clock as well as additional I/O such as PWM outputs and analog inputs
5 Raspberry Pi devices that could use battery backup and RTC

5 Raspberry Pi devices that could use battery backup and RTC

Because the Pi Platter is so versatile, it’s important to showcase some of the ways you can use it.  Currently, I have 5 demo designs.

      1. Raspberry Pi Zero with eInk display and solar cell showing time, battery voltage, and voltage graph
      2. Raspberry Pi B+ with mini touchscreen running python games
      3. Raspberry Pi Zero ver. 1.3 showing binary clock on a 8×8 LED matrix display
      4. Raspberry Pi B+ Security System with motion detector, 4×4 membrane keypad, camera and 2×16 LCD display
      5. Raspberry Pi 3 with 1TB hard disk

However, because I only have one demo Pi Platter board, I was only able to make one of the designs battery (and solar) powered for the faire.  Two key features of all the designs is that they are battery powered and that the GPIO connector is available for HATs – that is daughter boards that fit on top of the Raspberry Pi.  The Pi Platter connects through 4 pogo pins to the bottom of the Raspberry Pi Zero and through USB to other Raspberry Pi models.

Close up of 4 of the designs

Close up of 4 of the designs

The Saturday at the faire was a good way to make connections and talk to hob nob with fellow makers.

R2D2 was one of the hits with the kids at the Faire

R2D2 was one of the hits with the kids at the Faire