Which Sub-GHz module do you suggest?

Hi,

I have used NRF24L01 with TMRH20 library for a buiding automation proof of concept. Though it works, yet the 2.4GHz frequency has very limited wall penetration, so I am considering SI4432 or NRF905 (both at 433MHz). But it looks like they dont have a mature library on Arduino as compared to NRF24L01.

I am looking for a module with

  1. Sub-Ghz frequency
  2. A stable library on Arduino (nano)
  3. Low sleep/standby current
  4. Auto acknowledgement feature in hardware
  5. RSSI measurement.

What are your suggestions?

Thanks in advance.
Regards,
Wonderful IOT

The HC-12 modules have been mentioned favourably elsewhere in the Forum although I have no personal experience of them.

...R

HC-12s wont do 4 or 5 .
You are looking for a fairly expensive radio to do all that.

Does'nt HC-12 protocol do the auto ack transparently to the user, I mean how does it appear as a wireless UART, it has to do auto ack in its protocol, no ?

Also once the module is put to sleep, can I just wake up the remote device by sending a byte to it?

Thanks.

The HC12 is simply a bi directional transceiver, but it doesnt guarantee data integrity.
You have to implement some sort of error checking in whatever is sending the data to it.
You can wake up the module from sleep by sending AT style commands to it when its in
set mode.
If you want end to end data integrity you need something like one of these.

Though it works, yet the 2.4GHz frequency has very limited wall penetration

Have you tried the high power NRF24L01 modules? They meet all of your other requirements.

Hi,

2.4GHz has very poor wall and floor penetration even if that was not a problem, the high power units come with dipole antenna, whereas my application needs omni directional antenna.
In one commercial building (thick floor concrete slab) that I tested the PA version, I could not pass more than 2 floors, even across 2 floors there were lots of packet drops even at 250 Kbps.

Thanks,
Wonderful IOT

This might sound trivial, but have you considered wifi as in ESP8266 module? Maybe it doesn't directly comply with all your requirements but its cheap, very well supported and reliable.

I have had mixed results from nRF24 solutions as well and at the end went for a wifi option.

wonderfuliot:
Hi,

2.4GHz has very poor wall and floor penetration even if that was not a problem, the high power units come with dipole antenna, whereas my application needs omni directional antenna.
In one commercial building (thick floor concrete slab) that I tested the PA version, I could not pass more than 2 floors, even across 2 floors there were lots of packet drops even at 250 Kbps.

Thanks,
Wonderful IOT

In antennas, omnidirectional always refers to s single plane. Even a vertical monopole antenna is not omniodirectional in all planes. Turn the dipole antenna on it’s end to get omnidirection in a horizontal plane.

If you are looking for omnidirectional in both horizontal and vertical planes, then you really need to do more research on antennas.

Paul