Below is a description of the construction of a pager for a standard bite alarm.
With a range of 200 meters. The device operates in two modes:
1) Light + vibration alert
2) Light + vibration and + connected sound signal
To work, we need:
1) Cases (you choose as you prefer)
2) Buttons
3) LEDs
4) Audio plugs and audio inputs 2.5 mm
5) Standard bite alarm
6) Soldering iron
7) 4 optocouplers
And so let's start in order. I have such a bite alarm
At the bottom of the signaling device there is an output, as for headphones, only it has a 2.5 mm plug. When biting, the LED lights up on the indicator and lights up or blinks for 15-20 seconds. So while the LED is on, a small voltage is applied to this output, it was I who decided to use it.
A plug was purchased at the store
And 4 optocouplers, unfortunately there is no photo separately (( The operation of the optocoupler is as follows: when a small current is applied to two outputs, the second two outputs 1 and 2 will be closed, that is, it works like a button
This scheme was taken as the basis DIAGRAM and finalized.
Transmitter
And the receiver
I bought two suitable cases, I specially found the case for the transmitter to be with a battery compartment.
Spread boards for the size of the cases
And soldered all the details. Vibro motor took from an old phone.
Here's how it ended up
Transmitter
And the receiver
On the receiver case there are two switches, 1 to turn on the pager itself, and the second turns the sound on and off.
As you can see in the diagrams, the batteries are 9 and 12 volts, which far exceeds the power threshold of our circuit, so I had to put a voltage regulator at 3.3 volts AMS1117
This allows the transmitter to use a battery of minimum size with high voltage, which extends the life of the battery.
Next, take a piece of wire of suitable length and solder the plug to it
Another 3.5 mm plug is soldered in the photo, it was just for the sake of experiment. Its essence is as follows. Having disassembled the signaling device, I soldered the wires to the speaker terminals and brought out another output
All this I did to ensure that: When during the bite (let's say it was false or the toad hit the fishing line), the signaling device itself will emit only one peak, but the LED will light for 15-20 seconds, the pager in our hands will beep and flash for 15-20- seconds. And if you connect the transmitter to another output, which comes from the speaker, then only one peak will be transmitted to us and the pager, and it won’t squeak for 15-20 seconds. The refinement is not significant, but at times increases the productivity of this pager.
Here is a video of his work
This homemade pager is suitable for absolutely all types of signaling devices.
If you have questions, ask in the comments or in the PM, but it is better in the comments that others would have the opportunity to get around all the difficulties of construction.