I notice my DS18S20 and DS18B20 sensors, if there's a network failure or..
perhaps a hardware failure from overheating the sensor when I'm soldering wires
onto the leads, reports "85" as the temperature.
As far as I can tell the "crc8" value is correct in these instances.
a) why does it do this
On Sat, Jul 13, 2013 at 11:11 AM, Daniel MacKay wrote:
> I notice my DS18S20 and DS18B20 sensors, if there's a network failure or..
> perhaps a hardware failure from overheating the sensor when I'm soldering
> wires onto the leads, reports "85" as the temperature.
>
> As far as I can tell the "c
Gregg:
> How are they being powered? What sort of wiring method are you using?
They're on three wires, "Linear" style:
http://www.maximintegrated.com/images/appnotes/148/148Fig01.gif
being driven by a SheepWalk RPI2
http://www.sheepwalkelectronics.co.uk/RPI2.shtml
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On 07/13/2013 11:22 AM, Daniel MacKay wrote:
> Gregg:
>
>> How are they being powered? What sort of wiring method are you using?
>
> They're on three wires, "Linear" style:
>
> http://www.maximintegrated.com/images/appnotes/148/148Fig01.gif
What is the third wire? The above diagram only shows two
Gregg:
The three wires are:
1) Power, +5v
2) Ground
3) Data
On 2013-07-13, at 13:00 , Eloy Paris wrote:
> On 07/13/2013 11:22 AM, Daniel MacKay wrote:
>
>> Gregg:
>>
>>> How are they being powered? What sort of wiring method are you using?
>>
>> They're on three wires, "Linear" style:
>>
>
Hi Paul,
Have you had a chance to look into this?
Cheers,
Eloy Paris.-
On 07/06/2013 10:31 AM, Eloy Paris wrote:
> On 07/06/2013 08:34 AM, Paul Alfille wrote:
>
>> Great! Finally a real user to test this feature.
>
> Oh, I've had big plans for this feature for a while, but it's taken me a
> wh
On Sat, Jul 13, 2013 at 12:05 PM, Daniel MacKay wrote:
> Gregg:
>
> The three wires are:
>
> 1) Power, +5v
> 2) Ground
> 3) Data
>
> On 2013-07-13, at 13:00 , Eloy Paris wrote:
>
>> On 07/13/2013 11:22 AM, Daniel MacKay wrote:
>>
>>> Gregg:
>>>
How are they being powered? What sort of wiring
Daniel,
The origin of 85 was that the original sensors were 8 bit and only went
to 85c and thus all 1s (FF)was an error. When the extended the range to
125c and the bits extended, the error value was already set and produces
the problem you have. Hind sight says they should have used the extra
Wow Jerry, what a comprehensive and coherent answer. Thank you so much.
I think I'll take your strategy of just discarding all 85.000 values - at the
data collection point I'll turn them into a "U" undef which will propagate up
in the software to a missing value.
-dan
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