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Re: Photos of the insides of Fine Offset sensors.

Posted: Tue 30 Nov 2010 1:01 am
by ben-s
I've just bought a spare W8681 transmitter because I want to try some mods without breaking my station.
I'd like to take the sensors off the board and put them in the screen, with the main PCB re-cased and put elsewhere. I'd like to get better airflow over the sensors to see if I can improve the response time.

When I opened the case up, I discovered an update to the design that I've not seen listed anywhere else - the DCF antenna is now properly attached into the top of the case with a sensible amount of glue and a couple of foam spacers prevent the PCB rubbing on the coil.

My new Tx is the solar powered version, but looking at it, it seems the only real difference is in the screen, which has a mount for the solar pod on top. Power is fed to the Tx via pins 3 (-) and 5 (+) of the Rain connector, and the rain sensor plugs into the bottom of the solar pod.
Testing on my bench under a halogen desk lamp, the solar panel puts out between 5-6V open circuit.

I've attached a photo of the new DCF antenna position as well as both sides of the PCB for comparison with older units, and a labelled pinout for the solar pod cable.

Re: Photos of the insides of Fine Offset sensors.

Posted: Tue 30 Nov 2010 11:58 am
by Gina
That's very interesting :) Thank you for posting the photos :)

Re: Photos of the insides of Fine Offset sensors.

Posted: Tue 30 Nov 2010 3:50 pm
by ben-s
Just opened the solar pod up, nothing particularly interesting in there, a simple white masked PCB with the solar panel's support frame screwed to it.
The PCB has an RJ11 type socket for the rain sensor, a small tactile "reset" switch, which seems to short out the panel momentarily, and a captive lead with an RJ11 plug for the Tx.

There is a moulded 2x AAA battery holder in the bottom of the pod, under the PCB, but no contacts or batteries are installed.

This Tx kit was supplied with a pair of 2000mAh rechargeable batteries - labelled "rechargeable alkaline"
I don't know whether I'd trust that label, I've seen so called rechargeable alkaline cells before, and they leaked when recharged.

Pics for reference. If anyone feels like building their own equivalent panel, let me know and I'll draw up a circuit diagram and pinouts.

Re: Photos of the insides of Fine Offset sensors.

Posted: Mon 06 Dec 2010 10:57 pm
by Orion
And a couple of photos of the anemometer

Re: Photos of the insides of Fine Offset sensors.

Posted: Sat 05 Feb 2011 5:41 am
by mr.sneezy
Does anyone here recognize the Logo on the RX module or know any maker information ?
A search on Google Images came up blank.
Crop of the RX module attached.

Thanks,
Martin

Edit: I think I just got lucky with Google...
http://www.hoperf.com/upfile/RFM01.pdf

Edit2: Looks like they make all the main sensors in the wh1081 !

Re: Photos of the insides of Fine Offset sensors.

Posted: Sat 05 Feb 2011 9:49 am
by Gina
That's interesting :) Thank you for finding the info :) I thought it probably used FSK. That's Frequency Shift Keying for those who don't know. One frequency is used to transmit data 0 and another for data 1. This is a common modulation method for radio/wireless data transmission.

Re: Photos of the insides of Fine Offset sensors.

Posted: Sat 05 Feb 2011 10:27 am
by Orion
Nice find Mr.Sneezy
Here is the link for the transmitter
http://www.hoperf.com/upfile/RF02.pdf
Also Antenna info
http://www.hoperf.com/upfile/ANTENNAS_0102.pdf
And Pressure Sensor
http://www.hoperf.com/upfile/HP01S.pdf

Re: Photos of the insides of Fine Offset sensors.

Posted: Sat 05 Feb 2011 12:26 pm
by mr.sneezy
Orion wrote:Nice find Mr.Sneezy
It was a bit of luck. I was searching through general 433Mhz module datasheets and I noticed something familiar in one of them. It was the parts layout on the board, matched the posted photo here exactly. Then the 'bingo' moment :)

I have had a search around at using the module. They are a bit tricky to use, but it's been done by a few tinkerers so it's doable.

Now to see if I can find a cheap source that will sell one or two at a time. Then write some PIC MCU code (and post it here of course).
Martin

Re: Photos of the insides of Fine Offset sensors.

Posted: Sat 05 Feb 2011 11:50 pm
by Philip
Have just had to replace the bearing in the anemometer, the old one felt like it had a lump of grit in it and had an intermittent tight spot. New one came from simply bearings for the princely sum of £2.29 plus £1.50 post.

part number MR105.2Z simplybearings.co.uk

Philip

Re: Photos of the insides of Fine Offset sensors.

Posted: Sun 06 Feb 2011 10:13 am
by Orion
Wonder how easy it is to replace the bearings as it seem only to be held in place by melting the plastic
perhaps it would be possible to use a screw and a couple of washers
could you post a photo when you have done it
nice link by the way :D

Re: Photos of the insides of Fine Offset sensors.

Posted: Sun 06 Feb 2011 11:23 am
by Philip
Too late! it's already back on it's pole.

I did look at a better fixing method but there is very little to drill and tap a thread into and as it was a tight fit I decided to add a small drop of super glue and push it on.

Philip

Re: Photos of the insides of Fine Offset sensors.

Posted: Sun 06 Feb 2011 1:22 pm
by Gina
Philip wrote:Too late! it's already back on it's pole.

I did look at a better fixing method but there is very little to drill and tap a thread into and as it was a tight fit I decided to add a small drop of super glue and push it on.

Philip
A tight fit is all that's necessary.

Re: Photos of the insides of Fine Offset sensors.

Posted: Mon 07 Feb 2011 12:18 pm
by Charlie
Orion wrote:Nice find Mr.Sneezy
Here is the link for the transmitter
http://www.hoperf.com/upfile/RF02.pdf
Also Antenna info
http://www.hoperf.com/upfile/ANTENNAS_0102.pdf
And Pressure Sensor
http://www.hoperf.com/upfile/HP01S.pdf
If you want to build your own display, you might base it on the receiver used too, to make life simpler:
http://www.hoperf.com/upfile/RF01.pdf

The SDI output is a standard, so using a PIC or similar to translate to RS232 should be really straight forward - making decoding the data a simple matter.

Re: Photos of the insides of Fine Offset sensors.

Posted: Mon 07 Feb 2011 12:38 pm
by mr.sneezy
Charlie wrote:If you want to build your own display, you might base it on the receiver used too, to make life simpler:
http://www.hoperf.com/upfile/RF01.pdf
The SDI output is a standard, so using a PIC or similar to translate to RS232 should be really straight forward - making decoding the data a simple matter.
Thanks Charlie.
Yes the RX is the RFM01. A search around on Ebay finds a guy selling the Transceiver version (RFM12) for around $12AU (inc post). The TX side could be disabled. I can't find the RFM01 cheap yet...
SPI is standard, but it's implementation in this module is fairly involved due to the number of parameters to be setup, and the vague datasheet. Many posts around on the WWW of people having issues understanding it.

I've had two thoughts of note since I last wrote. One is that the RFM12 Transceiver could actually be used as a range extender, the distance to the sensor TX could be much farther. Hope also make a high power version with PA, and that seems to have up to 3km reach under the right conditions.
These ideas rely on the sensor TX being too far away from the RX station to 'hear' it, but the RFM12 to be in between where it can. The RFM12 repeater would hold the data burst (via MCU), then send it on again a moment later. Hope that makes sense.

Second thought is that it may be possible to 'port sniff' the SPI lines in the RX display station and decode the RFM01 setup parameters as the MCU sends them at power up. That would save guessing the bandwidth and other hard to guess RF settings. That would be a once-off thing, only to find the information once (and post it here).

Martin

Re: Photos of the insides of Fine Offset sensors.

Posted: Mon 07 Feb 2011 6:55 pm
by hans
Any possibility to change the transmission intervall from 48 seconds to say 30,10 or even continuously?

yet another "mystery" solved of this "simple station". :clap: :clap: