[PD] Sensors GPIO Raspberry Pi Pd

[Martin Peach]

On 2013-03-27 18:31, Martin Peach wrote:
> On 2013-03-27 17:17, Julian Brooks wrote:
>> Hey Martin,
>>
>> Good to hear you've got one of these too.
>>
>> Yes I meant [comport] with the xbee rather than [hid] sorry, getting my
>> physical input objects confused.
>>
>> Will check out the links you provided as part of my getting up to speed.
>>
>>
>> So, managed to get the sensors out of the cardboard box.  They are
>> tiny.  Like little sci-fi robot eyes.
>>
>> 1st problem is that we don't have any of these:
>> 'JST (Japan Solderless Terminals) - PHR-4 - Housing, 4way, 2mm
>>
>> http://uk.farnell.com/jst-japan-solderless-terminals/phr-4/housing-4way-2mm/dp/3616204
>>
>>
>> Which is a vital £0.04.6 of equipment as the sensors pins are way too
>> tiny to be poking bits of wire into.  These attach to the bottom of the
>> board and then 2mm cabling attaches to them and out to the Pi.
>>
>> Got some off ebay as farnell has a £20 minimum spend that's a bit over
>> getting 10 of those suckers.  So going to have to wait a few more days
>> as I can't find any in my vicinity at all.  Bollocks.
>
> Yes I got mine at Digikey. You need the terminals as well as the
> housings. I crimped the terminals to some 28 gauge wire and also put a
> bit of solder but not too much to plug them up.
>
> Today I managed to get data using an Arduino and the Wire library, with
> 4.7k pullup resistors on the clock and data lines. The packets are only
> 32 bytes, not 35 as the app note says. Not sure what's up with that.

I changed the default buffer size in Arduino's wire library from 32 and 
now I get 35 bytes as advertised. The crc calculation is not giving me 
the right answer but that doesn't seem to matter. I get 16 pixels of 
temperature, it's detecting warm as well as cold objects, quite a nifty 
sensor!

Martin