Zoomx's postbag

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ahull
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Re: Zoomx's postbag

Post by ahull » Mon Jan 29, 2018 1:57 pm

What is inside the "Digoo DG-R8S 433MHz Wireless Digital Hygrometer Thermometer Weather.." is it just a blob, or are there any chips with recognisable markings?
Can you hang a scope on the pin that goes in to the transmitter to see the data?
- Andy Hull -

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RogerClark
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Re: Zoomx's postbag

Post by RogerClark » Mon Jan 29, 2018 8:07 pm

Very interesting for various reasons.

Just to help other forum members, can you post what SDR dongle you are using and also what SDR software.

I normally just use my SDR dongle with SDRSharp ( now called AirSpy) to listen to various things, e.g Amateur radio, aviation etc
But I know there are loads of decorders ( mainly command line tools j on Linux to decode different protocols e.g. Weather satellite images,

Also, thanks for posting the link to that 433MHz receiver, I have the cheap version, but I also have a much bigger receiver module, I bought from a local electronics shop, ( which is supposed to be much better)

However I normally only use the 433MHz transmitter modules, with RCSwitch to control things like radio controlled mains sockets.


Also...
I have an external temperature and humidity sensor, but never worked out what protocol it uses. I think it’s a variation of an Oregon Scientific protocol but when I looked , several years ago, no one had written a library to decode it, and I do not have time to write one, so I just use the disolay that came with the sensor

I would like to combine all my sensor reception, using a ESP32,as I made my own BLE temperature sensors , but I write a Android app to view them.
I did start to write an ESP32 program to receive the BLE sensor data, but did not have time to finish it.

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zoomx
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Re: Zoomx's postbag

Post by zoomx » Mon Jan 29, 2018 10:34 pm

@ahull,
just checked: a black blob! It uses a 433MHz module so there is a pin. I don't own a scope but... I have a cheap clone Saleae Logic Logic Analyser somewhere! Anyway I have already successfully decoded it.

@Roger
The SDR dongle has an Elonics E4000 tuner and a RTL2832U bought about 10 years ago. No brands at all.
Image
It is exactly like the white one. I found very similar dongles that have a IR receiver that mine doesn't have, they have a little hole for it.

As I wrote before I used a software called rtl_433. I used SDRSharp also just to check if there were a transmission and I found that the signal has a very large band, maybe because the antenna was close.

The cheap 433MHz receiver board worked with an Avidsen remote controlled mains socket but it was unable to work with the Digoo. Maybe I made some mistakes.

I have also a single probe Maverick BBQ thermometer that I was unable to decode. I found some libraries that

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RogerClark
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Re: Zoomx's postbag

Post by RogerClark » Mon Jan 29, 2018 10:38 pm

Thanks

The SDR dongle looks identical, at least on the outside, to the one I have.

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zoomx
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Re: Zoomx's postbag

Post by zoomx » Tue Jan 30, 2018 9:25 am

This is the temperature/hygrometer inside
Image
It seems clear to me with the exception of the black blob.

There are three test point, T3/CLOSE:F, T24/TX and T4/NOR/TEST. T24 and and T3 seems a duplication of the pushbuttons but they have independent lines on the PCB.

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ahull
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Re: Zoomx's postbag

Post by ahull » Tue Jan 30, 2018 9:46 am

Pretty much what I expected, generic microcontroller blob, bare humidity sensor, bare thermistor (NTC? probably 100k Ohm @20C ? - cos they are dirt cheap) , generic 433MHz transmitter module.

If you have the parts to build the pig-o-scope, you could view the data by hooking up to the input of the transmitter module, since the thing runs at around 3V and the data rate is going to be fairly slow. You could also swap the transmitter module for some other generic transmitter module of your choosing to put the data on a better frequency.
- Andy Hull -

pierre75
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Re: Zoomx's postbag

Post by pierre75 » Fri Feb 09, 2018 9:15 pm

Hello
In my experience, DG-R8S sensor signal form is :

Header : 650ms high and 8000ms low
Body : a set of 36 bits
bit 0 : 650ms high and 2000ms low
bit 1 : 650ms high and 4000ms low

bit 0-4 : 1001 (maybe vendor id)
bit 5-12 : id (change every power on)
bit 12-13 : 00 (exept when you press check => 01)
bit 14-15 : channel-1 (select. for exemple 01 = channel 2)
bit 16-27 : temperature in degre (must be divide by 10. for exemple 298 = 29.8)
bit 28-35 : humidity (assume 10 seems = LL from panel)

I tested with esp/arduino code using attachInterrupt(digitalPinToInterrupt(D7), change, CHANGE); and change custom function

Good luck

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zoomx
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Re: Zoomx's postbag

Post by zoomx » Fri Feb 09, 2018 10:00 pm

Thanks pierre!
there is also a library to decode it, you can find the github link in the previous page.

pierre75
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Re: Zoomx's postbag

Post by pierre75 » Sat Feb 10, 2018 6:21 am

Huhu, shame on me :-)
From now, I can improve my experience with battery's bit. Thanks !

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zoomx
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Re: Zoomx's postbag

Post by zoomx » Sat Feb 10, 2018 7:32 am

Why shame on you?
I modified a library already existent but with your information I can write my own or understand better how it work!

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