Solar powered rf transmission

[shantanu@india]

Hi,
I was thinking of using small solar panel+battery combination to power active ID tags in a steel plant stockyard(200 m radius).
About 1000 odd products scattered all over the place would give a roll call at specific intervals to the central inventory monitoring system.
Any ideas?

[charliecoutas]

I've just used some HC12's for a hide-and-seek system in the museum's escape rooms. They have a low power mode where they will sit listening while only consuming 80uA. When they receive a character they wake up a sleeping 18F26K22 which deals with the request, like a transponder, then goes to sleep again. the total current while asleep is 100uA and for a very short time while transmitting, about 110mA. Ideal for solar power?

I thought active ID tags had a pretty short range?

Charlie

[shantanu@india]

Thanks Charlie.
Just had a look at HC12.
1000 m coverage at full power, is that line of sight?
Shall order some.

[charliecoutas]

Yes, that's what the spec says. There are some rip-off ones (as usual) so I suggest you Google "rip off HC12" first.

I have used several of these and they give good results. See https://www.elecrow.com/download/HC-12.pdf

Charlie

[John Drew]

In a steel plant's stock yard there will be many reflections and probably dead spots. Placement of the radios will be very important, antenna up high, along with the solar panel and preferably line of sight to the control unit otherwise multipathing, distortion and loss of data may happen.
Even with line of sight there will be reflections as steel is moved around and there will be destructive and constructive interference. It might be all okay, just suggesting be prepared. RF is interesting, never assume.
Cheers
John

PS Directional antennas for the slaves will reduce reflection problems to a large degree.

[shantanu@india]

Thanks for the tips John. I'll remember.

[Giuseppe]

I too have used the HC-12s in the past and the original ones perform well.
You can also consider the SX1278 LoRa Module UART are more performing and cost a little more

[Giuseppe]

I forgot as a solar module you can use this controller
https://it.aliexpress.com/item/1005003124317266.html?spm=a2g0o.order_list.0.0.43443696rbe0vz&gatewayAdapt=glo2ita
A BMS must be added in series if you use a lithium battery.

[shantanu@india]

Thanks Guiseppe.