Transmitters and receiver

Support
1

Hi

I am wanting to set up 20 - 50 240v transmitters that send a signal back to one receiver when power is turned off. Could be a distance of 100m between transmitters and receiver.

Thanks

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2

Hi Matt
Wth no power how is a transmitter going to send a signal??
cheers Bob

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3

Hi Matt,

If youā€™re after simple radio, you might want to check out the PiicoDev transceiver:

It has 111 available addresses, so 20-50 should be fine. A PiicoDev expansion board on a Pico can handle battery charging, so with a plug pack and a small LiPo at each power point you could keep things topped up and working after the power goes out, provided you look into low power modes for the transceiver and pico.

As for detecting power, the VBUS pin on the Pico only goes to 5.1V when itā€™s charging (hence your plug pack is getting power), so you could use a voltage divider to get this down to 3.3V and read it with a digital pin or ADC.

Let me know if this seems like a good idea, or if you had something else in mind :slight_smile:

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4

Hi All.
At this stage there is not enough information available to offer much advice. Matt, the whole story please.

There are many scenarios that would fit this.
Separate radios, power monitors and processing kit for each site. Unless you had separate receivers they would all have to be set to the same frequency and a coding system for ID.

If the monitor positions are close together then 1 radio TX with processing to monitor all sites would maybe do.

I think a lot depends on the physical layout of this project as there are probably more options or a mixture of scenarios possible.
Cheers Bob

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5

H Bob

It doesnā€™t have to send a signal back saying lost power but if I remotely see that an individual transmitter has lost signal then that would be the confirmation that device has lost power? That make sense?

Thanks

6

Hey mate

I am after something very simple. Iā€™m an electrician but have no idea what your talking about hahah. Iā€™ll tell you what Iā€™m trying to do and see if it makes sense.

I have a factory that I want to identify which circuit breakers in the switchboard control the different power points around the factory. I want to plug a heap of individual transmitters into the power points around the factory and stand at the switchboard and see either on my phone or laptop the network of transmitters. As I turn circuit breakers off at the switchboard I want to see the relevant transmitters lose power. It can be that simple. Does that make sense?

Thanks

7

Hi Matt

It does as long as the individual transmitters are identifiable. A bit useless if they arenā€™t.

Where are you. Personally I have yet to see a factory or industrial installation where each power outlet is not marked or indicated in some way which circuit breaker on which board is supplying power to that outlet. I havenā€™t got a copy of the SAA rules but I would be very surprised if there were not some stringent regulations pertaining to this.

Anyway in my personal (I emphasise personal) opinion for what it is worth I think I could find an easier way to do this. Might not be as much fun though.
Cheers Bob

8

Hey Bob

I ā€˜m in Melbourne.Yes all outlets and equipment SHOULD be marked but doesnā€™t always happen. Iā€™ve worked quite a few places where this is the case.

I am all about simple and easy so whats your idea of making this work?

Thanks

9

Iā€™ve tried using the wifi plug in adapters that a lot of places sell. They pair back to an app but only problem with those is you can see when they lose power. You can get some of them to notify you but thats after 30 mins of no power.

10

Hi Matt

I canā€™t think of anywhere this does NOT happen. In NSW anyway I get the impression this is a requirement. At worst there should be a list in the power board showing where all the power comes from and where it feeds to with a list of outlets.

If this exercise is to be a one off to record and mark outlets I would think plug in light globes or some other visual indication to map and record the distribution of outlets would be a bit laborious but would work.

BUT if you want a continuous monitoring system that is another matter. If you want to monitor individual outlets that could be getting cumbersome. My next level would be monitor breakers at each distribution board with an alarm back to base indicating a problem at that particular board. Then a problem investigated downstream from there. Sort of a family tree monitor if getting down to individual outlets proves to be a non starter.

The other point is that if a problem causes a breaker trip in a power distribution board a whole circuit of outlets is going to go off and an individual investigation is going to be needed anyway to find the actual culprit.
Cheers Bob

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Hey Bob

Yes a one off to record and label. Problem with doing globes or other testers I have is itā€™s labour intensive in that thereā€™s so much back and forth from switchboard to outlets throughout factory. Itā€™s not it canā€™t be done like that itā€™s just the method I am wanting to use will be faster. Donā€™t want continuous monitoring just want a way of seeing when the transmitters or other devices lose power as I switch circuit breakers off. Doesnā€™t really bother me what devices are but if I can pair them or transmit a signal back to my phone or laptop then see when they lose power.

Thanks

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12

Hi Matt
Yes it would be faster when you get it built up and working. But what I was getting at for a one off it is a pretty fair project which could get quite complicated. By the time you get it all up and running you probably could have walked around the factory several times.

BUT if you can afford the time and funds the experience gained will be invaluable and could well be a good investment. Particularly if you can get a working system that could have other uses down stream.

Will have a think about it.
Cheers Bob

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13

Highly recommend the device linked by @James, connected to a Pi Pico.
If it sent a ā€œIā€™m Aliveā€ message every so often you would not need to measure power loss.
Loss of the ā€œIā€™m Aliveā€ message could be detected by the switchboard unit and displayed.

There are other limitations and considerations, like how often do you transmit, if every device transmitted at the same time it would be a problem.

Alternatively the switchboard device could initiate the message asking if a particular device is powered. If no message then the assumption would be it is off.

There are many options, it just depends on how you want to set it up. The linked device would work nicely though for 20 to 50 devices.

Cheers
Jim

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14

Hi Matt
An expansion of Jamesā€™ idea.
Each ā€œslaveā€ has a TX/RX and some smarts to respond to a unique code. When this code is received a short message like ā€œOKā€ or something is transmitted back to the ā€œmasterā€.
The master polls the slaves one at a time, sending the unique code for each one. Then listens for a reply. Reply (OK or something) power is on. No reply assume power is off.

You indicate you want to use this as a one off to identify power circuits. Once you have done that a system like this could be adapted for all sorts of things. If your factory has any sort of automation this sort of thing could be used to monitor for problems, end of a particular process and the list could go on so it need not be any sort of wasted exercise.

The fine details I would have to leave up to you or anyone with experience with this sort of thing.
Cheers Bob
PS: All the TX/RXs have to be on the same frequency.

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