OpenMarine
How have you implemented temp/preasure/humidity? - Printable Version

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How have you implemented temp/preasure/humidity? - SkipperEarly - 2016-04-03

Have managed to get gps and ais working - and I love OP more and more - so I want to get ready for the next step - environmental data.

How the sensors need to get connected is explained in the manual but my question is how have users done this?
- wire the sensors up and keep all in the same rpi-case? - or
- use a breakout board, connect it there and put the breakout board in the rpi-case (it now does not close properly anymore) - or
- put the sensors in another housing and run a 4 wire cable back into the rpi-case - or ?

In the first 2 options probably the temperature readings will be distorted by the processor heat. Whats your experience there?

Can someone share pictures from the actual setup (not the schematics - they are already in the manual)
  
Thanks for info!


RE: How have you implemented temp/preasure/humidity? - affinite - 2016-04-04

(2016-04-03, 06:18 PM)SkipperEarly Wrote: Have managed to get gps and ais working - and I love OP more and more - so I want to get ready for the next step - environmental data.

How the sensors need to get connected is explained in the manual but my question is how have users done this?
- wire the sensors up and keep all in the same rpi-case? - or
- use a breakout board, connect it there and put the breakout board in the rpi-case (it now does not close properly anymore) - or
- put the sensors in another housing and run a 4 wire cable back into the rpi-case - or ?

In the first 2 options probably the temperature readings will be distorted by the processor heat. Whats your experience there?

Can someone share pictures from the actual setup (not the schematics - they are already in the manual)
  
Thanks for info!

Until analogue inputs are supported, the only inputs I'm interested are temperature and switches. I have 3 of the DS18B20 temp sensors specified in the manual on a 3m extension cable. These (will when fitted in 2 weeks time) measure exhaust/mixing elbow temp, Alternator temp and seawater/cooling water IN temp. The switches (also on the extension cable) sense coolant flow stopped and bilge pump activated..
I assume that the pressure/humidity sensors would be happy in the Pi case but others will no doubt confirm.


RE: How have you implemented temp/preasure/humidity? - Sailoog - 2016-04-04

If you can, keep your environmental sensors out of the RPI case.

As you have pointed, temperature, humidity and pressure readings from in will be really different than out. In summer here in the Mediterranean,  you could fry an egg over a fully equipped OpenPlotter enclosure Smile
Besides this if you can build a fully waterproof enclosure, pressure readings will be always the same, the pressure that was inside the enclosure when you closed it.

Connect all your I2C environmental sensors to the same 4 wires line. Make a small enclosure for them but remember, not completely sealed Smile


RE: How have you implemented temp/preasure/humidity? - SkipperEarly - 2016-04-19

Have put the two environmental sensores (humidity/temp, pressure/temp ) in a seperate housing and wired up as describted in the manual. Have upgraded to OP 0.8beta as advised and restarted OP but in the ICU tab the sensors are not detected.

I wonder if I damaged the sensors when soldering them onto the board. Can measure 3.2V on the pins.

Any advise on how to proceed now?

Thanks

I meant of course I2C sensor tab above.

I also observed, that when I start within OP the actual OP section after the logo it takes nearly half a minute until the program actually starts and opens the tab.


RE: How have you implemented temp/preasure/humidity? - Sailoog - 2016-04-19

Open OP in debug mode to see if any error is returned. Do this twice, sensors connected and not connected, to see if there is difference.


RE: How have you implemented temp/preasure/humidity? - SkipperEarly - 2016-04-20

(2016-04-19, 05:01 PM)Sailoog Wrote: Open OP in debug mode to see if any error is returned. Do this twice, sensors connected and not connected, to see if there is difference.

followed your advise but no message is given in debug terminal - only difference is when sensors are not connected op starts within seconds but when connected it takes approx half minute.

Can I somehow measure the functionality of the sensors (V/A/ohm meter?)


RE: How have you implemented temp/preasure/humidity? - SkipperEarly - 2016-04-20

SOLVED: I measured the resistance and voltage between the VIN/GND and SDA/SLA and found values to indicate that the sensor is not burned. I then un-soldered and resoldered the sensor into the base. Obviously I had a shortage between SDA/SLC which caused the strange behaviour.

Calibration: I assume sensors are already calibrated and do not need to be re-calibrated - wouldn't even know how to do this, as no such option is in the gui.


RE: How have you implemented temp/preasure/humidity? - Sailoog - 2016-04-20

Congratulations. Yes,they are pre-calibrated and don't need to do nothing.