Cumulus Support

Hi Lars

I said it was complicated
I made a mistake in the drawing - reverse the positions of the resistor / capacitor - so resistor from +ve to DTR
Regards
Alan

Alan, are you in a position to test this with RTS/CTS?

Hi
I have some old female 9 pin leads so I guess I could tack one on when I get a moment.
Alan

Hi
Your wish is my command
RTS/CTS result (same Cap/res config)
Apart from a starting OFF the debug looks OK (Again very heavy hosepipe rain)

Alan

apenwith wrote:Hi
Your wish is my command
RTS/CTS result (same Cap/res config)
Apart from a starting OFF the debug looks OK (Again very heavy hosepipe rain)

Alan

Alan, you're a gentlemen, thank you.

I think you've also now earned a title, "Cumulus test engineer"

Perhaps, we should also now include your new rain description in current conditions "Again very heavy hosepipe rain"

The resistor, just 1/4w?

Hi,

IMHO 800 kohms is far too high to do anything "useful". I believe Ole recommended 800 ohms to reduce the risk of damage to the relay contacts (if "shorting" a charged capacitor).

The "life" of relay contacts depends on the current they are breaking (bearing in mind a "break" can occur if the contacts bounce) and the type of load (inductive loads are bad). In this application the life is likely to be "infinite". For example the "reed relay" contacts in the FO anemometer are less substantial than Hydreon's but operate millions of times each year (several thousand times for each mile of wind run).

For "predictable" filtering of contact bounce you should probably be putting about 1 kohm in series with the relay contacts, plus the capacitor (and maybe a few kohms resistor in parallel) between DTR and DSR (or RTS and CTS), observing the correct polarity. But the optimum will depend very much on the actual serial port hardware (which can vary considerably as the original "standard" was defined more than 50 years ago).

Cheers, Alan.

@AllyCat, could you post a schematic of that please?

Hi Alan
I realise it's not a proper filter but it seems to work but a current limiter series resistor might be a good idea.
Regards
Other Alan

Hi

BIG MISTAKE - the resistor I used was 800ohms NOT 800K - apologies to anyone trying the wrong one.

Alan

The quoted size was actually:

You could probably also use the 10uF in series with a resistor say 47 -100 ohm – that would limit the discharge current and protect the contacts better.

But more importantly - what ever works

i used a 150 ohm resistor which is as close to the figures given as i could find to hand which seems to work

I was able to turn on debug during a very short shower here. I see the same double tips as before.

1110.534703 : 1:57:39 PM WU Response Code: 200 Response = success
1110.535031 : 1:57:39 PM RG11 1 state change: On
1110.535031 : 1:57:39 PM RG11 1 state change: On
1110.535125 : 1:57:39 PM RG11 1 state change: Off
1110.539703 : 1:57:44 PM Updating Wunderground

pete_c wrote:I see the same double tips as before.

Was that with a plain cable, or with a capacitor and/or resistor?

Same as before; just a plain cable. I just did notice a software update and will install newest beta.

Looking at the rain totals; they are similiar to previously reported. (compairing Davis tipping bucket, RG-11 connected to 1-wire, Dallas Rain tipping bucket and RG-11 connected to Cumulus). Will post shortly.

Just installed my RG 11. Alan's configuration with 10uF and 800Ohm works great. I use 40m of CAT5 cable and serial to usb converter. No double tips at all!
Just waiting for rain now for some comparison.

Thanks again Alan. Great help.