Today we make an experiment with the Gumstix. Our problem was to know if in turning at 1000rpm in a ventilator the WiFi will work correctly.
The first was to get a wireless power source to the Gumstix.
We got a lot of problems with that. First of all, the power connector of our Tobi expansion board is damaged (thanks to Copterix ) which cause a lot of reboot at any movement… We solved this with a lot of gaffer.
Secondly our hacked connector (with sticky tape) for the battery was not very well either and caused some trouble. Thanks to the PACT project which order a lot more than necessary 9V battery connector we improved our power line.
And last problem for the power, our board was rebooting in loop before we had a chance to login in… Simple problem but hard to guess, our battery didn’t deliver enough current. It was easily solved with a second battery in parallel.
Now, add a lot of gaffer to secure into place the batteries, the Gumstix and the antenna and we’re ready.
Of course, Murphy’s law requires, at this exact time the Gumstix decide to no longer properly boot and the WiFi to stop working. But with a little of black magic that finally worked and we have done our tests.
Our ventilator was missing of power and can’t get to its maximum speed (~1100rpm) with our board mounted on it (we could do better with a better balancing of the weight). But at the speed that we reach we succeed to had no loss of bandwidth (to confirm with a faster ventilator) which is a good news.
The bad news is that even placed on a table at 20cm from the computer we can’t do better than 1.5MB/s of transfer rate in WiFi (and 3MB/s in ethernet…) which is some kind of disappointing.
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