Phidgets Plugin Discussion

Posted on
Mon Sep 30, 2019 4:37 am
landry offline
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Joined: Jul 30, 2017

Re: Phidgets Plugin Discussion

Hi Brkinet

I have a apogee barometric sensor connected to phidgets 2/2/2 interface that is plugged int a fidgets SBC3 .
The sensor is configured as a as generic 0-5 volt device. I have tested this several times and it does not update voltage if there is a change unless i unplug the 2/2/2 usb connection and then replug it in. The pressure device changes are very small deltas. The values I get are as expected since I compare to external barometric pressure sensors used as controls. Before I talk to Phidget.com com do have any suggestions?

Thanks for all your support!!!


Dave

Posted on
Mon Sep 30, 2019 8:35 am
berkinet offline
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Location: Berkeley, CA, USA & Mougins, France

Re: Phidgets Plugin Discussion

landry wrote:
...The pressure device changes are very small deltas. The values I get are as expected since I compare to external barometric pressure sensors used as controls. Before I talk to Phidget.com com do have any suggestions

The only thing I can think of is the threshold. try setting it to 1, or even 0. Though 0 might change far too often.

Posted on
Tue Oct 01, 2019 5:11 am
landry offline
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Joined: Jul 30, 2017

Re: Phidgets Plugin Discussion

Hi Berkinet

Lowered threshold value to 1 and it worked!!
i guess no change was being posted since barometric trends in changes are very small unless you have a strong storm front. Changes in the volt are in the 0.020 to 0.030 range.

I bought the epogee since I never really got the Phidget absolute pressure to work. Went back and looked at and that now works.!

I recommend to users to apply the 15-115kp pn 1141 (and not the 20-400 kp; changes in voltage would be smaller) for barometric measurements.
Now writing python scripts to report barometric pressure trends.


You are the best Berkinet!

Posted on
Tue Oct 01, 2019 8:25 pm
landry offline
Posts: 30
Joined: Jul 30, 2017

Re: Phidgets Plugin Discussion

Hi Berkinet

After reading the Data Interval/ChangeTriggers section of the phidgets website, your suggestion to change the trigger threshold to 1 makes a lot of sense.

The sensor I am using was configured as a 0-5 volt sensor corresponding 150 Mpacal to 1150 Mpascals.
The barometric range is roughly 950 Mpascals to 1030 Mpascals which approximately corresponds to 4.1 volt to 4.47 volt signal range.
The ChangeTrigger property of a channel enables a filter that only passes data when that data has changed by an amount greater than or equal to the ChangeTrigger. for example, a value of one will pass any signal greater than 1 volt up to the sensor limit which in my case is 5 volts. In other words any signal greater than 1 volt will be recieved when the threshold set at 1. Given the bsrometric range, the thresh old value set a 3 or lower pass all useful data for my sensor.

With threshold defaults set at 10 no signal was ever detected during the data intervals since that setting filters out all signals less than 10 volts.
If the sensor was configured as aaw data 0-1000, that threshold value of 10 will pass any value greater than 10 which is greater than 99% of the raw signal range.

You may want to have minimum threshold set automatically at 0.01 when the user configures the sensor as as a 0-5volt sensor.

I went through this exercise so i could understand the difficulties I was having when setting up a 0-5 volt sensor.

Thanks again for a great plug in.

Posted on
Fri Oct 04, 2019 10:41 am
loafbread offline
Posts: 136
Joined: May 25, 2009

Re: Phidgets Plugin Discussion

Any thought to making the Phidgets22 plugin an MQTT client?
Might make the whole Phidgets interface more flexible or universal.

Posted on
Fri Oct 04, 2019 10:55 am
berkinet offline
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Re: Phidgets Plugin Discussion

loafbread wrote:
Any thought to making the Phidgets22 plugin an MQTT client? ...

No plans at this time. Maybe later.

Posted on
Sun Oct 06, 2019 9:10 pm
hamw offline
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Joined: Mar 31, 2008

Re: Phidgets Plugin Discussion

I'd like to monitor a wine fridge for temp/humidity. Do you think the best way is to get an SBC and several TH units? Do you think an SBC is easy to setup, even for the marginally technically able? Also I saw the VINT discussion... no reason to go down that path, and it is not supported by the plugin, right?

Posted on
Fri Oct 25, 2019 5:16 am
berkinet offline
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Re: Phidgets Plugin Discussion

hamw wrote:
I'd like to monitor a wine fridge for temp/humidity. Do you think the best way is to get an SBC and several TH units? Do you think an SBC is easy to setup, even for the marginally technically able? Also I saw the VINT discussion... no reason to go down that path, and it is not supported by the plugin, right?

Sorry for the long delay in responding... vacation in Italy :D

Essentially, you need an interfaceKit (like the 1018) and a computer. The SBC3 does that in one package, but it is no longer available. The new SBC4 is a VINT device, though you could connect a 1018 to it. However, the good news is you can achieve the same end with a Raspberry-Pi, a USB hub and a 1018. There are several guides to setting up the R-Pi. Take a look at Instructable for one.

However, rather than using the 1018, you may wish to use a 1048 4-Input temperature sensor and some thermocouples. The 4106 and 4107 would work well for your application. Insert the probe into a wine cork, then fill a wine bottle with water and place the cork firmly into the bottle. You are now measuring the actual temperature of the liquid rather than the air. Or, just buy something like this. You could have up to for bottles placed around the cabinet, plus the one on-board sensor. (BTW, this is exactly what I have done.)

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