RE: measure height of snow -
f4aii - 05-03-2018
good results, eager to try it with the well
thanks
RE: measure height of snow -
engolling - 05-03-2018
In the attachment you can find a board and a schematics file for the snow height measurement module. I tried to make is as compact as possible.
I have a voltage regulator and some level shifters on the Arduino Nano board.
Every feedback concerning schematics and layout is welcome, since this is not my daily business. It would also be great if somebody says that's ok

.
The next step will be, that I will order a small amount of PCBs and then I would like to create software interface e.g. simply exchange a 16 bit unit via I2C to the TX module.
Maybe a standard interface can be defined, as requested in my other thread.
Regards,
engolling
RE: measure height of snow -
werk_ag - 05-03-2018
My best suggestion is that you try to make that the sensor in a way that it could be read as it as a Temperature / Humidity sensor. This way the changes on the TX code will be only the needed to read a value from the sensor. Don't forget, that the reading whatever it will be, must further be mapped to an Davis extra sensor, which only accepts data with the lenght of one byte for temperature and one byte for humidity, with some limitation. Please refer to Davis Vantage Serial protocol for more info.
Humidity field: integer from 0 to 100
Temperature field: integer from 0 to 255 with a offset of 90 (positive values only from o to 255-90)
So, think wisely about the output scale of the snow sensor. Belive me, I have really good reasons to be very reluctant to add any kind of sensor that isn't supported by a Davis weather station.
RE: measure height of snow -
engolling - 05-03-2018
Hello Werk,
thank you for your feedback ... for one moment I didn't think of the limitations

.
But since communication and variable structure is only software on the Nano changes are more or less easy.
In the first step I would like to make working hardware and then getting software done.
RE: measure height of snow -
engolling - 06-03-2018
New day, new revision

.
I added a LED to give a feedback if communication is running and took the interrupt pins on a header because you never know if you have to trigger anything.
Moreover I changed the layout but I don't know which one tends to be better since I have no experience in this direction, so I would be glad if someone could give me a hint.
RE: measure height of snow -
engolling - 20-03-2018
PCBs are in production.
In principle I have a programmable RS232 to I2C converter to read the laser ranging device and emulate an I2C temperature sensor.
This is how the board will look like:
At the moment I have a device driver for the following lasers:
- HOLO NSCE NS-XX (
http://www.shhongle.com/Pro_show.asp?id=9)
- HIREED Laser (
https://www.aliexpress.com/wholesale?spm=2114.search0104.8.31.563f8f58lxMyXa&initiative_id=QRW_20180320141918&SearchText=hireed+laser&productId=32793950499)
-SNDWAY Lasers which are very spread could be supported thanks to Michael. This laser was my first try and I failed, but this guy got it hacked
https://www.mictronics.de/2018/02/laser-distance-meter-hack/
So if someone wants to test the laser measurement, I will give away some test PCBs without parts for shipping and a small handling fee of 3 EUR (if the PCBs work...

)
RE: measure height of snow -
engolling - 09-04-2018
The PCBs have arrived view days ago and all parts are ordered.
My other WeatherDuino PCBs are almost ready to use. So first results are expected soon (depending on the weather outside maybe in a few weeks since spring has arrived

) .
As I said, if there is anybody who wants a pcb for testing, feel free to contact me because next winter is already coming in 8 month
RE: measure height of snow -
JT118 - 16-04-2018
Latest Issue of Meteorological Technology International
http://www.ukimediaevents.com/pub-meteorological.php
Just for interest.
RE: measure height of snow -
engolling - 24-04-2018
Hello,
there are some good news with the laser distance measurement.
The following achievements have been made:
- Emulation of a HTU21D sensor
- Data is received in the RX station as extra sensor
- Unit is dm (deci meter) allowing a precision of 1cm up to a snow height of 100cm. (If the snow will be higher the value won't be displayed right on the display, but transmission to the weather station via davis protocol should go further).
- Setup height can be stored in EEPROM in setting the Pin int0 to GND
- The value (setup height - measured height) is transmitted to the RX station
- A running median filter is put in place to smooth the readings
The following features are planned to be integrated:
- Support of two other laser ranging devices
Know issues:
- Since the ordering hand was faster than the brain there is a routing error on the PCB. Instead of A4 and A5 the pins D4 and D5 are routed to the I²C connector to the TX module. Therefore some extra wires have to be soldered to the PCB. More explanation will follow soon.
Last but not least you can find the actual software attached. I know it is not very nice - this have never been my strengths but I will try, as soon as I'm satisfied with the functionality, to improve the Software that it will be clearer.
@ JT118 - thanks for the information.
Greetings, engolling
RE: measure height of snow -
werk_ag - 24-04-2018
Good job engolling.
It seems that in next winter, the WeatherDuino users, especially those where snow is frequent will have a new weather instrument.
Quote:Since the ordering hand was faster than the brain there is a routing error on the PCB

I know it very well, I think it makes part of the developing process. I consider myself happy when I manage to have a pcb without errors just at second attempt.