ZgatewayRF Reception

hartman9 · June 14, 2022, 2:57pm

Looking to control a Fan via RF and have it working except for the reception is quite poor.

I am using a Wemos D1 Mini with a CC1101 Wireless Transceiver 433MHZ + SMA Antenna Wireless Module with ZgatewayRF.

I identified the remote frequency by the FCC ID to be 304.0 and confirmed with an RTL-SDR.

The receiving range I am getting is maybe 5 or 6 feet line of sight. I’ve tried holding it up high, different receive pins on the Wemos, even a second D-Sun CC1101 just to make sure it wasn’t the board, I even tried an ESP32 Dev Board. Nothing improved my reception and I am hoping somebody could five me some suggestions. Note the transmission range does appear to be greater at about 10 plus feet through the wall into the next room where the fan resides.

I am at a loss. I’ve tried different antennas and one actually improved the reception for a period of time. I ended up turning the Wemos off for the weekend and came back a few days later and the same behavior with little reception was occurring. There is probably something simple I am missing and would love to solve this problem. Any help is greatly appreciated. Thanks.

DigiH · June 14, 2022, 3:57pm

Hi @hartman9, in my experience with 433MHz CC1101 transceivers I also find that their range is pretty poor, so I only use them with rtl_433_ESP devices. For my general RF gateway i use a SRX882 receiver and STX882 transmitter, which I find to have substantial better range.

Have you also tried adjusting the CC1101 frequency to 304.0, to see if the range improves, which possibly would also be better with a dedicated 315Mhz version CC1101?

github.com

1technophile/OpenMQTTGateway/blob/development/main/config_RF.h#L115


      
              {"rain_mm", "rain", "mm", "precipitation"},
              {"rain_rate_mm_h", "rain", "mm/h", "precipitation_intensity"},
              {"rain_in", "rain", "in", "precipitation"},
              {"rain_rate_in_h", "rain", "in/h", "precipitation_intensity"},
              {"rssi", "rssi", "dB", "signal_strength"},
              {"snr", "snr", "dB", ""},
              {"noise", "noise", "dB", ""},
              {"depth_cm", "depth", "cm", ""},
              {"power_W", "power", "W", "power"},
              {"light_lux", "light", "lx", ""},
              {"lux", "lux", "lx", ""},
              {"uv", "uv", "UV index", ""},
              {"uvi", "uvi", "UV index", ""},
              {"storm_dist", "storm distance", "mi", ""},
              {"strike_distance", "strike distance", "mi", ""},
              {"tamper", "tamper", "", ""},
              {"alarm", "alarm", "", ""},
              {"motion", "motion", "", "motion"},
              {"strike_count", "strike count", "", ""}, // from rtl_433_mqtt_hass.py
              {"event", "Status", "", "moisture"}};
          #  endif

Hope this helps.

hartman9 · June 14, 2022, 3:59pm

Yes, I’ve defined the frequency as 304 in the config_RF.h as you have shown here and it’s always been defined as such since I first uploaded the firmware via Arduino.

DigiH · June 14, 2022, 4:13pm

Then I really think it’s the same CC1101 lower range experience which I also encounter with both my dedicated 433Mhz and 868Mhz CC1101s, compared to the much better range with the SRX882/STX882 combo

I suppose that’s why they are recommended in the docs, unless a CC1101 is required as with rtl_433_ESP.

hartman9 · June 14, 2022, 5:25pm

Can the STX882/SRX882 work with a frequency of 304Mhz? All the ones I see say 433Mhz.

DigiH · June 14, 2022, 6:05pm

For best results I would use a dedicated 315Mhz STX882/SRX882, which are usually available in the US and through ebay/Aliexpress or another Chinese web store, at is preferable for your 304 MHz. Harder to get directly in the EU as the 315Mhz band here is restricted to official use only, but since you seem to have a US/Asian Fan already …

You might want to wait and see if anyone else might have any other usggestions to improve your CC1101 range, the above is just through my experience with the CC1101 range compared to the STX882/SRX882.

hartman9 · June 14, 2022, 6:41pm

I placed an order for a 315Mhz version I found on AliExpress. During the two month delivery window maybe somebody will give me some additional ideas for the CC1101. Thanks again for all your help.

1technophile · June 15, 2022, 1:02am

My best guess is related to antenna match versus the frequency, did you calculate the antenna length required for 304mhz?

hartman9 · June 15, 2022, 6:08pm

I did use an online calculator to get down to 1/4 wavelength and a telescoping antenna for the results with no difference. Not sure if that is the correct way going about it or not?

NorthernMan54 · June 21, 2022, 12:57am

@hartman9 I found that with one of CC1101 units that placing it so that the antenna was vertical ie straight up worked better than being horizontal. But for a second unit, it made no difference.

hartman9 · June 29, 2022, 8:00pm

So I received the 315Mhz STX882/SRX882 modules today and tried them out with ZgatewayRF following these recommendations from another post for the Wemos D1 Mini. I have not tried transmitting but I am having no luck with receiving. Is ZgatewayRF the right one to use? Or because I am using frequency 304 mhz it just won’t work?

Hello to all,
I’ve decided to join this RF iot mania and well, get some knowledge while I’m at it

I followed the RF guide for ESP8266.

I’m using wemos d1 mini and the stx882 & srx882 pair and can’t seem to get it fully working.

Let me explain a bit further, it is wired as per the guide, so stx882 is wired like:
vcc to 5v on wemos
gnd to gnd on wemos
data to RX on wemos
I’m not sure if the transmitter works, because I can/t get the receiver to work to read the codes which I would try sending.

The receiver is superheterodyne SRX882 because the guide said it is better and it is wired like this:
vcc to 5v on wemos
gnd to gnd on wemos
data to D2
cs is unplugged

I then modified the config_rf.h to set the receiver pin to 4 (D2) and emitter to 3 (RX) and uploaded the project to the wemos d1 board.
I than get it to connect to the mqtt server and it also reads the codes from a remote I have that is working on 315mhz.
But here is the deal, I have a doorbell that works on 433mhz and I can’t read the code it is transmitting.

Is it possible that the srx only recieves on 315mhz and how can I make it work on 433mhz also?

Regards, Jure

1technophile · June 29, 2022, 8:48pm

Hello,
Yes it won’t work, too far from the nominal frequency of your receiver

DigiH · June 29, 2022, 8:51pm

I’m just trying to find the band range info again, I was pretty sure, that 304MhZ was in the 315Mhz range, starting at 300 as far as I remember?!?

Only finding some posts where people have 304 (pretty much all with fans for 304Mhz working fine with the 315Mhz, but also one where it didn’t, only after swapping a component of the 315Mhz version

1technophile · June 29, 2022, 8:58pm

Seems that the srx882 can go from 314.9 to 315.1mhz

DigiH · June 29, 2022, 9:05pm

Apologies to @hartman9 for sending you off in that direction, with it only taking even more fiddling with the STX882

hartman9 · June 30, 2022, 1:11am

No big deal as you know the modules are cheap and it was worth a shot.

dsaul560 · September 19, 2023, 12:49am

Were you able to fix this problem? Im having same issues on 303.87 mhz. Have ESP32dev + CC1101 with coil antena. The transmission range for C1101 is great and can control fans from the other side of the house, but the reception is like 10 inches. Im using RTL_433 module. Thanks!

hartman9 · September 19, 2023, 12:20pm

I was able to improve it a little with a 9 inch antenna. The real solution I feel would be to use the C1101 as a transmitter and an SDR to receive signals. Another solution out there is something called a Yardstick, which I have not tried, but it looks to be essentially a two way SDR.

dsaul560 · September 19, 2023, 4:43pm

Thanks for your reply. I ordered cheap SDR to confirm the frequency of the remote, it says 303.875 on FCC but who knows. The fan responds to that though. I don’t really understand why I can send from several rooms away with walls, and receive only with 5 inches. I also have an Sonoff RF Bridge that picks up fine the 433s and is small, hidden behind a cabinet. I will try your suggestion of 9in antenna, didn’t want a big antenna sticking out, but if works its ok.

1technophile · September 20, 2023, 1:31am

Could you try to build with platform espressif32@3.5.0 . A user reported that it improved its reception. Would be interesting to confirm this.