Distance measurements into Mervis
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Hello team,
At SUNTHERM we're using the Unipi together with Mervis to control our heating system. As part of this system we need to monitor the waterlevel in a tank.
For this purpose we intend to use a HC-SR04 based ultrasonic device like this:
http://www.modmypi.com/blog/hc-sr04-ultrasonic-range-sensor-on-the-raspberry-piHow do I connect the 4 pins to the Unipi, when the GPIO header is used by the board to board connector?
How do I import the value from python into Mervis as a global variable?Looking forward to some valuable input:-)
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Hello team,
At SUNTHERM we're using the Unipi together with Mervis to control our heating system. As part of this system we need to monitor the waterlevel in a tank.
For this purpose we intend to use a HC-SR04 based ultrasonic device like this:
http://www.modmypi.com/blog/hc-sr04-ultrasonic-range-sensor-on-the-raspberry-piHow do I connect the 4 pins to the Unipi, when the GPIO header is used by the board to board connector?
How do I import the value from python into Mervis as a global variable?Looking forward to some valuable input:-)
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Hello,
I am afraid that this piece of HW cannot be used with Mervis because you need the exact time of the pulse from the sensor. Mervis is not a perfect solution for that because the DI are not read that often.
Br,
Tomas
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Hej Tomas,
Thank you for the response.
Would it be more suitable with a device like this:
https://www.adafruit.com/datasheets/1786_Chemical_eTape_Datasheet.pdfConnected to Analog input?
rgs Morten:)
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You can use the first simple voltage divider schematics for reading resistance with UniPi 1.1. Below is a schematics with values calculated for use with sensor with 400-5000ohm resistance.
Also please remember that the onboard 12V might not be stable enough for using for such purposes!