Recent content by geoff

My old AAG anemometer/wind-vane has not got much life left. It really never was suitable for long term exposure to the weather, the plastic case is not waterproof, the bearings need regular replacement, and the plastic itself is almost disintegrating because of exposure to too much UV. So...

Put me down as a possible "volunteer". I have 2 of the old moisture sensors which now work okay after my mod with the transformer. I have one UVI sensor which as far as I know is working okay. What problem with the UVI are you referring to ?

I used to have a HB solar sensor mounted with the photodiode directly exposed to the sun, and pointing vertically upwards. After some time the diode died and I made a guess that the solar intensity got too much for it and "burned it out". So with my next one I used the ping-pong ball idea...

The "expensive" weatherproof Maxbotix sensor has now surrendered to the humidity. Curses. However, plan 'B' based on the capacitance meter seems to be working just fine. I used the concept at http://njhurst.com/electronics/watersensor/. A bit of electronics to convert the capacitance...

Disconnecting the ethernet cable made no difference.

You need 3 wires at the moisture sensor board. GND, DQ, and +12V. The 12V can be more or less, but needs to be at least 7v I think. The regulated 5v wire is not needed. I still suspect a wiring problem. Disconnect the cable run at the hub, plug in a short un-terminated cable instead...

Power is 16v from one of your hubs. The sensor is physically close to one of your solar sensors and a AAG weather station (on the same wire). The other sensors behave as expected. Are you thinking that maybe the power is "dirty" at the sensor ? The 1-wire does run alongside an ethernet...

I've recently installed one of the new UV sensors. The graph below shows data plotted on 2 min intervals so far today. It is typical. Notice the "spikes" one of two each hour. There is no obvious explanation for this, the sensor is in full sunshine right next to my hobby-boards solar...

It sounds like a wiring problem to me. If you have 16v at the hub you should have 16v at both of the sensors. The mositure needs at least 7v to work. Time to check the cabling I suggest.

I was lucky enough to "inherit" a calibrated laboratory thermomenter and have tried to use it to calibrate my assorted 1-Wire temp sensors. At one time I connected 7 or 8 random sensors and stuck them together in a small box to try and keep them all at equal temperature. I found they varied...

I decided to give this Maxbotix sensor a try. Some interesting discoveries along the way in case anyone else is interested in experimenting. I bought the sensor from "Sparkfun", about USD25. I found a really easy way to connect it to 1-Wire was to canibalise a spare hobby-boards solar sensor...

I havn't built it yet, but this is on my list of projects. I want to measure water depth up to approx 2.5m in a number of water tanks. There are some ideas on sensor design at http://njhurst.com/electronics/watersensor/ I suspect getting the sensor reliable will be harder than...

Confirming ... it is working perfectly (at last!)

Something like this: link There will be 4 connectors. Use a multimeter to figure out which pairs are connected. Wire one pair to the sensor connections on the board, and the other pair to the sensor. Unless you are a dab hand with a soldering iron try and find a transformer with longer...

Fixed it ... I think. I put a small isolation transformer between the board and the sensor and now (I think) it's fine. The device is a 1:1 600 ohm isolation or decoupling xformer, typically used in modems or other things attached to a phone line. A couple of dollars from your local...