Author Topic: ID-4001 connected to Davis anemometer  (Read 655 times)

0 Members and 1 Guest are viewing this topic.

Offline MitchSF

  • Member
  • *
  • Posts: 10
ID-4001 connected to Davis anemometer
« on: March 31, 2017, 04:40:05 PM »
Hi All,

Below is a link to a short video of a project I'm working on. I've successfully connected an Arduino MKR1000 to the ID-4001, controlling wind speed and direction. The next step, and the easiest part since it's already been done, is to connect the anemometer to the Arduino.

The Davis anemometer uses a variable resistor to indicate wind direction. That has to be converted to a four bit Gray Code, which the ID-4001 expects from it's original sensor. Wind speed from the anemometer is indicated by a magnetic reed switch that closes once per revolution. The ID-4001 sensor sends pulses at a frequency of 10.5/mile/second, so a conversion has to be made there, too.

The reason I used the MKR1000 instead of the less expensive Uno, is because the MKR has WiFi. At some point I'd like to experiment with downloading wind data from a web site. I'm not sure where because I haven't researched that yet, but I am sure that it can be done. With that option wind data won't be instantaneous, but it will make the ID-4001 usable where an anemometer can't be mounted, such as in an apartment.

I also may add a small, two or three line digital display to the interface board.

I'd like to try to emulate the outdoor temperature sensor using a digital to analog converter, but using a 5v reference, I don't think the range will be sufficient. Maybe an op amp can be added, but I'm not an EE and that's beyond what I can do. If anyone has advice on that, please let me know.

When everything is up and running, I'll post an update.

https://drive.google.com/file/d/0B3kvk05blsPJeXZIWTRGN2JCUjQ/view?usp=sharing
« Last Edit: March 31, 2017, 04:45:15 PM by MitchSF »

Offline MitchSF

  • Member
  • *
  • Posts: 10
Re: ID-4001 connected to Davis anemometer
« Reply #1 on: May 08, 2017, 07:01:42 PM »
The Arduino is simulating all sensors including temperature, and the Davis 7911 anemometer is interfaced. Weather data is also downloaded and displayed from Weather Underground. If anyone is interested, I'll post the pc board design and software to Github when I'm finished, in a few weeks.

Offline DaleReid

  • Forecaster
  • *****
  • Posts: 1183
    • Weather at Eau Claire, WI
Re: ID-4001 connected to Davis anemometer
« Reply #2 on: May 09, 2017, 08:45:50 AM »
Ingenious.
I, for one, would like to see you share this and help others save these old but neat devices.

Thanks.
ECWx.info
&
ECWx.info/t/index.php

Offline MitchSF

  • Member
  • *
  • Posts: 10
Re: ID-4001 connected to Davis anemometer
« Reply #3 on: May 09, 2017, 09:29:10 AM »
Thanks.  I will.

Attached is a preliminary schematic. A MAX3232 RS-232 - TTL chip will be added so the time and date can be set on the ID-4001. That will only work with the Data Professionals CPU upgrade, though.

I'm a software developer, at least I was, not an EE. If anyone has comments or improvements to suggest, please let me know. As it is now, everything works.

Once this is done, the ID-5001 should be no problem.

Offline MitchSF

  • Member
  • *
  • Posts: 10
Re: ID-4001 connected to Davis anemometer
« Reply #4 on: May 22, 2017, 05:20:02 PM »
Here's the board layout. The project is coming along nicely. Obviously it's gone far beyond just interfacing the anemometer.

Offline DaleReid

  • Forecaster
  • *****
  • Posts: 1183
    • Weather at Eau Claire, WI
Re: ID-4001 connected to Davis anemometer
« Reply #5 on: May 22, 2017, 09:05:01 PM »
Thanks, Mitch.
Your effort will no doubt close the gap in available booms and sensors and the number of old (but good) stations that have sat inside, safe and sound. 

The worse part of the four ID-5001s that I've been involved with or owned, was the terrible humidity sensor, even the ones sold to replace those originally shipping with the first kits.  If you can get the interface working so that some of the more stable, accurate and cheap as pennies units can be attached, more of these old gizmos will live on.

Dale
ECWx.info
&
ECWx.info/t/index.php

Offline MitchSF

  • Member
  • *
  • Posts: 10
Re: ID-4001 connected to Davis anemometer
« Reply #6 on: May 22, 2017, 09:46:16 PM »
Thanks, Dale. I haven't looked at the ID-5001 yet, but I read the technical description for humidity sensor operation. It appears to work similar to the temperature sensor, so I added additional hardware for it. I probably won't get to the software and testing for a couple months because I want to make sure the ID-4001 works perfectly, first.

The sensors I'm using are BME280, with an I2C interface. They are the six pin versions available on eBay for under $5 each. They read pressure, humidity, and temperature.

I thought the wind display could be used for other functions, but that won't work. It responds much too slowly. I'm experimenting with a small OLED display, about 1" square, to display humidity inside and outside. I tried to include everything possible on the hardware side, software will have to catch up over time.

I hope others will build and use the interface. I can't test it with the anemometer here because it's impossible to put it up in a good location in our highly regulated homeowners association. I know wind direction is perfect and speed should be good based on the math, but we'll see. Same with the rain sensor for the ID-5001.

Offline MitchSF

  • Member
  • *
  • Posts: 10
Re: ID-4001 connected to Davis anemometer
« Reply #7 on: August 17, 2017, 09:05:54 PM »
Almost finished. Maybe another couple weeks, then I'll order some pc boards. I switched processors to the ESP32, otherwise the hardware design remains unchanged. Another month or two and I'll get to the ID-5001 humidity sensor software.

I doubt there will be enough interest to make some kits available but if there is, I just may do it.


Offline DaleReid

  • Forecaster
  • *****
  • Posts: 1183
    • Weather at Eau Claire, WI
Re: ID-4001 connected to Davis anemometer
« Reply #8 on: August 17, 2017, 10:03:09 PM »
Thanks for the update and I am eager to hear your progress on final design and all. 

All I can say for interest in 5001 and the 4001 stuff is that the things that are usually not sold on eBay are the sensor packages.  People go into their folks' places after they pass or move or have to be moved to assisted living and the display is always there, along with the indoor temp sensor and maybe the humidity, but the outside stuff especially if up on a roof or tower is missing, rendering the boxes almost useless. 

If you can adapt something to feed those boxes with reliable signals, there may be more interest than you realize.  But to get kits together and try to sell them other than a small test batch might be financially a problem, but over the long run, or with selling them with the idea that you have to gather the stuff to ship them out when sold might be worth the effort, too.

Keep at it.  I eagerly await and would volunteer to test one of the early ones out if you have need to sell one first and I can fiddle with it to give you feedback and endorse it if it works as well as it seems to be for you.

Dale
ECWx.info
&
ECWx.info/t/index.php

Offline MitchSF

  • Member
  • *
  • Posts: 10
Re: ID-4001 connected to Davis anemometer
« Reply #9 on: August 17, 2017, 10:23:56 PM »
Thanks for the comments, Dale. Do you have an ID-4001, and can you do basic soldering? I'll contact you when the project is finished.

I don't think there is any way to recover a month of software development and days for hardware design. But I'm retired now, so those things don't matter as much.

Offline eyecue

  • Member
  • *
  • Posts: 43
Re: ID-4001 connected to Davis anemometer
« Reply #10 on: August 18, 2017, 08:28:37 PM »
MY ID 4001 used the optical transistor and sender and the beam was broken by the strobe disk. There was no reed switch in it.
Cocorahs, Skywarn, Aficionado of weather. Davis VP2  pro wireless, Oregon Scientific and DIY.

Offline MitchSF

  • Member
  • *
  • Posts: 10
Re: ID-4001 connected to Davis anemometer
« Reply #11 on: August 18, 2017, 09:36:22 PM »
MY ID 4001 used the optical transistor and sender and the beam was broken by the strobe disk. There was no reed switch in it.

True. The Davis 7911 anemometer uses a reed switch that closes once for each revolution. Software translates that to a format that emulates output from the original Heathkit anemometer.

Offline DaleReid

  • Forecaster
  • *****
  • Posts: 1183
    • Weather at Eau Claire, WI
Re: ID-4001 connected to Davis anemometer
« Reply #12 on: August 18, 2017, 10:50:17 PM »
Mitch,
I have three or four of the 4001s around and three (that I recall) 5001s.

I can do the bigger Surface Mount stuff, but I don't have a reflow solder station or a binocular microscope, so for normal circuit boards and wiring I'm pretty much OK.

Dale
ECWx.info
&
ECWx.info/t/index.php

Offline MitchSF

  • Member
  • *
  • Posts: 10
Re: ID-4001 connected to Davis anemometer
« Reply #13 on: August 18, 2017, 10:57:52 PM »
Dale, no SMD on the interface, just the microcontroller, and they come assembled. I'll contact you when ready.

Mitch,
I have three or four of the 4001s around and three (that I recall) 5001s.

I can do the bigger Surface Mount stuff, but I don't have a reflow solder station or a binocular microscope, so for normal circuit boards and wiring I'm pretty much OK.

Dale