It is possible to use arduino LoRa modules for controlling solenoid lock inside safety box

Janis59

Joined Aug 21, 2017
1,350
Signal via closed earthened gapless metal box comes out, hardly diminished but comes. Contrary, from outside to inside it is principially ecranated due Faraday Cage principle. Thus, Your chance is drill the small hole where put the Lora antenna.
 

Thread Starter

meowsoft

Joined Feb 27, 2021
470
If you want a reliable connection, you should mount an external antenna. How far from the control point is the box?
About 8 meters, also there is some sensor inside safety box, that detect's when vibrate, puched, rotated, and similar action
 

Yaakov

Joined Jan 27, 2019
3,522
About 8 meters, also there is some sensor inside safety box, that detect's when vibrate, puched, rotated, and similar action
For 8m LoRa is overkill. I would recommend you use the nRF24L01+PA+LNA module for the box since it have facilities for an external antenna and you can use the ordinary version for the control or the +PA+LNA version if you prefer.

I would also make the link supervised. That is, I would poll the box end from the control periodically to check that it is still operating. If it doesn't respond, you know you have a problem before you need the link to work and find out it is down.
 

Thread Starter

meowsoft

Joined Feb 27, 2021
470
For 8m LoRa is overkill. I would recommend you use the nRF24L01+PA+LNA module for the box since it have facilities for an external antenna and you can use the ordinary version for the control or the +PA+LNA version if you prefer.

I would also make the link supervised. That is, I would poll the box end from the control periodically to check that it is still operating. If it doesn't respond, you know you have a problem before you need the link to work and find out it is down.
Yes... that linked is supervised, arduino is always monitored by raspberry Pi using ethernet, and arduino have unique response, so if response is tampered or arduino or lora inside safety box disconnected they triggered alarms, also make face recognition scan to hidden surveillance camera, if person is detected, siren can be trigger
 

Thread Starter

meowsoft

Joined Feb 27, 2021
470
Yes... that linked is supervised, arduino is always monitored by raspberry Pi using ethernet, and arduino have unique response, so if response is tampered or arduino or lora inside safety box disconnected they triggered alarms, also make face recognition scan to hidden surveillance camera, if person is detected, siren can be trigger
But... how to prevent someone from break antenna ?, that safety box is contains many many copper, and copper theft rate is very high
 

Yaakov

Joined Jan 27, 2019
3,522
But... how to prevent someone from break antenna ?, that safety box is contains many many copper, and copper theft rate is very high
If you supervise the link, as I mentioned, if the antenna is broken you will get an alert when the poll fails.
 

Janis59

Joined Aug 21, 2017
1,350
Any case when expected box-made attenuation is ca 80-120 dB the LORA (7.30 USD) is much better choice than NRFL (0.99 USD). Lora is working in urban obstacles up to 3 km afar whilst NRFL may harvest the 1 km only at clear sight countryside obstacles.
 

Yaakov

Joined Jan 27, 2019
3,522
Any case when expected box-made attenuation is ca 80-120 dB the LORA (7.30 USD) is much better choice than NRFL (0.99 USD). Lora is working in urban obstacles up to 3 km afar whilst NRFL may harvest the 1 km only at clear sight countryside obstacles.
In my opinion the proper way to do this is with an external antenna, protected as well as possible, and a supervised link.

It makes no sense to me to put it inside an RF tight box and hope it gets enough signal to operate.

If there is an external antenna, the nRF24L01+ is completely adequate and cheaper.
 

Thread Starter

meowsoft

Joined Feb 27, 2021
470
In my opinion the proper way to do this is with an external antenna, protected as well as possible, and a supervised link.

It makes no sense to me to put it inside an RF tight box and hope it gets enough signal to operate.

If there is an external antenna, the nRF24L01+ is completely adequate and cheaper.
Ok... if there is about 25kilograms of copper inside box, can RF modules be affected or distracted ?
 

andrewmm

Joined Feb 25, 2011
1,757
Ok... if there is about 25kilograms of copper inside box, can RF modules be affected or distracted ?
All very abstract this, interesting,

BUT

You mention SAFETY in the first post.
Not certain how much we can advise on safety designs, we give advice, but its up to you as to is it safe or not.

So what happens if the safety fails ?

25 Kg of copper, sounds like one heck of a transformer ?
or what is it ?

The electrical environment inside the box is liable to have more effect on any radio signal than the pure presence of copper/

I'd be a bit happier if you'd give some more background on what the overall is all about.

25 Kg is also ( allegedly ) about the amount of coper inside a Nuclear bomb firing circuit...
 
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