Internal pressure sensor

Stroller stroller at
Tue Oct 6 20:05:00 CEST 2009

On 6 Oct 2009, at 02:18, Werner Almesberger wrote:
> Stroller wrote:
>> This barometer is self-contained and connected to the i2c bus, a
>> _relatively_ simple addition. If there is demand for the barometer -
>> although I'm inclined to agree with Rask that there wouldn't be -  
>> then
>> it might it be justified to add it were Brazil ever to go into
>> Freerunner production.
> Here's where Open Design Hardware changes the scenario: if you have an
> (open) base product, you can design, produce, and deploy small changes
> for a special interest group at a comparably low price - a bit higher
> than if the change was part of the mass-produced design, but
> considerably lower than any traditional alternatives.
>> software installed. The software would have to be closed-source,
> [... more horror material ...]
> Why bother ? Even if we assume for a moment that you can't make money
> selling unencumbered software, you'd have the enhanced hardware
> already as a kind of dongle. Also, since this would be a highly
> specialized niche product, I would expect customer loyalty to be high.

Honestly? To add the barometer appears a very easy task. It involves  
soldering two wires, right?

If you were to start a business based on this, you might charge $100  
markup to make the modification but also to cover the cost of the full- 
time job writing and supporting the software. I think more might even  
be reasonable, or you might have tiered packages depending upon  
software features.

The Freerunner is readily available mail order - if a student in your  
local town were to offer to upgrade the hardware for $20, sorry, I  
think the business would be completely undermined. And there are Linux- 
competent students in every town - the "dongle", as you call it, is  
too easily manufactured by anyone. I love & believe in Free software,  
but I just don't know that it's realistic to expect to make money out  
of it that way. Were I ever - as a sole-trader presently - to write  
commercial code, I would probably GPL it in my will.

Rau1 remarks on the readability of the screen - he surely is far more  
familiar with the current state of the sport than I am, since I have  
not flown in 5 years. In this case it might be better to base a design  
on a custom Gumstix-based board and a black-and-white screen, so the  
discussion becomes entirely moot.


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