Best configuration for rtl_wmbus option

[alvaromemo]

Im using a RTL dongle to detect 433Mhz water meters using this options.

wmbusmeters rtlwmbus:434.475M:t1,c1 MyWater izar '*' NOKEY

It works perfectly, but i want to know how to:

• Use more Gain or set to Auto (AGC)
• Use a different sample frequency; i mean, for wmbus i know it must be 1200Khz, but in case it is different, how i set it?
• Which are the best settings to have more sensitivity and get more telegrams. Right now i'm using a 4dbi dipole antenna.
  Thank you.

[weetmuts]

You can specify your own rtlwmbus command line like this:

wmbusmeters 'rtlwmbus:CMD(/usr/bin/rtl_sdr -f 868.95M -s 1600000 - 2>/dev/null | /usr/bin/rtl_wmbus -p s)' MyWater izar ANYID NOKEY

You can run this command outside of wmbusmeters if you just want to check for reception of telegrams.

You can modify the sample frequency as long as it is a multiple of 800KHz and you specify -d to rtl_wmbus.
Check the README at https://github.com/xaelsouth/rtl-wmbus

You have to read up on the rtl_sdr settings for gain etc. I am not an expert on these unfortunately.

Here is the current available information on antennas and long range:
https://github.com/wmbusmeters/wmbusmeters-wiki/blob/master/ANTENNA.md
https://github.com/wmbusmeters/wmbusmeters-wiki/

[alvaromemo]

Ok, can you explain why 800Khz?, which are the implication of the sampling rate?.

[weetmuts]

No sorry. But it is probably due to how the decoding is implemented in rtl_wmbus. The sample rate was initially fixed, but now you can change it as long as you provide the correct -d option to rtl_wmbus.