Kettlepop: A Limited Edition Popcorn Computer
When I moved to China last year, I didn’t know what was in store for me. All I knew is that if I was here in Shenzhen instead of in Oakland, CA, that I could obtain any component and have assembled any PCB within minutes and hours instead of days and weeks. Since 2006, I have been sourcing components from Hua Qiang Bei, where some of the worlds largest electronics markets happen to be, and today I live five minutes away.
Last year, after Next Thing Co. was liquidated, I was able to obtain 662 GR8 System-in-Packages which happened to be the last stock available on earth. What made the GR8 so special was that the DDR Memory was included in the package along with the SoC (CPU) which meant that the hardest part of a complex system design and manufacture was already done for you or so I thought.
Even though, the original design for Kettlepop, the C.H.I.P Pro, was open source and thousands were manufactured, I learned that the supply chain was not optimized. In tradition with it’s first principle, C.H.I.P, the nine dollar computer, which was also open source and tens of thousands were manufactured, C.H.I.P Pro was designed to be as inexpensive as possible, as such, sacrifices were made at every step to drive down the cost of goods.
The memory chosen for C.H.I.P Pro was 512MB Toshiba NAND Flash Memory because it was about a dollar cheaper than it’s more reliable counterpart eMMC Memory when you buy direct from the manufacturer. Unfortunately, without an initial order of thousands of pieces one has to resort to the open market to source this component. I found that the cost of this component on the market was higher than 8GB eMMC direct from the manufacturer Longsys which my company Source Parts had recently partnered.
The change to eMMC to NAND was simple enough electrically. However, the new Memory required some support components that make it work. This included a small resistor network which we selected in the form of a 0201*4 package which means that four tiny 0201 resistors are combined in one component. We selected this component because it is the same package size used on the original C.H.I.P. and since we were also designing a new derivative of C.H.I.P at the time, named Popcorn, also with eMMC Memory, it made sense to use a component that was common between the two since we would be ordering large quantities.
When it came time for manufacturing ten prototypes of Kettlepop, our sourcing agent informed us of some bad news. The resistor network we chose was only available from one vendor in Beijing and would take up to three days to arrive in Shenzhen. A little extra lead-time could be acceptable for mass production but when we found out the pricing for samples of $0.50 a piece and around $0.30 in large quantity compared the next largest package size of $0.07 a piece for samples and $0.05 in large quantity we knew immediately we needed to do another revision. Unfortunately, we already ordered the PCBs for the first revision so we went ahead and ordered the samples.
This strip of 100 pieces of sample resistor networks costs $40. That’s more than the cost of ten pieces of eMMC Memory.
To make it worse, the strip was damaged in shipment and five pieces were lost. This may not seem like much but when each piece is $0.50 that’s a loss of $2.50 USD.
As for prototype manufacturing, Design for Manufacture (DFM) feedback from the factory was minimal. They wanted to know where pin 1 of the RF switch was located and the polarity of the ESD components to be sure placement was correct. I marked these on the assembly drawing as seen below and the boards were shipped to me in less than a week.
Fortunately, all the hard work designing a derivative lead to a successful prototype and a Mass Production ready design.
Kettlepop is a perfect computer on module for a startup looking to quickly develop and produce a limited quantity of beta units to trail their product. It is pin-to-pin compatible with C.H.I.P Pro and software will run the same.
We are offering 500 units of Kettlepop for $19,500 USD at a price of $39 each.