Bite Indicator

[Andrew Leigh]

Hi,

I don't have the technical know how but am hoping someone could help me design a fish bite indicator that would replicate the scream of a reel as the fish takes the bait.

Without wanting to re-invent the wheel it seems to be standard to have a wheel over which the line travels. There would obviously be some form of rotary encoder on the wheel.

Can one get a click sound to activate on the movement of the line and have the click to increase in tempo as the wheel increases in speed.

Could an old PC mouse suffice as the encoder?

Cheers
Andrew

 

[duffy]

I think an old PC ball-mouse wheel assembly would work fine - if anything, it would be TOO sensitive. You could reduce the sensitivity with a counter chip, or a couple of pulleys, or blocking out some of the slots in the little wheel.

The electronics will be pretty simple, I think most of the work in this project is mechanical.

The output of the opto in the mouse can easily drive a simple, cheap audio amp through a DC blocking capacitor. You can buy the amp, or make it yourself.

Why not crack open the mouse and take a couple of pix of the circuit board and upload them? I could point out where to connect the power, ground, and capacitor.

 

[Andrew Leigh]

Thanks,

will rummage around for a broken ball mouse.

Do you think that an optical mouse would be more convenient?

Thanks
Andrew

 

[duffy]

More convenient in some ways, less in others.

I tried running some string and bits of wire (have not tried monofilament) past my optical mouse, it will reliably detect cords down to about .032" in diameter. This is better than I was expecting, and maybe good enough for your purposes, so that's not an issue.

The big issue looks like the speed. The fastest optical mouse sensor I could find was the Avago ADNS-3080. It has a top speed of 40 inches per second. Most optical mice (mouses?) have a top speed of 14 ips. I think a fish might go faster than either of those.

The other issue is decoding the data from the mouse. Now instead of an amp and a capacitor, it's a microcontroller and a hundred lines of code.

 

[Andrew Leigh]

Hi Duffy,

thanks for that. Optical is well beyond me then, got my IT guy at work looking for a ball mouse for me to play with. Will send the photo then or perhaps it may be better to buy a device? With a bought device it may be easier to set the interupt frequency by making a larger disc?

What I am hoping to achieve is an audible sound as the fish starts playing with the bait. The fish are typically European Carp and Catfish. As the fish takes line (normally a little to start with) the buzzer would sound for each interuption occuring at the opto. As the speed of the line increases so will the "frequency" of the sounds which will indicate the rate at which the fish is making off with the bait.

I would also like to include an LED which hopefully can be connected in parallel to the audable circuit as an identical warning but a visual one for night fishing.

So if my understanding is correct. The output of the opto will arrive at the input of the opamp which will magnify the signal to the point that it either drives a buzzer type device or a transistor if more power is required. I have tried to implement bits from a project I have just completed, here is my crude attempt at the schematic.

The signal comes in through the blocking cap as you suggested.
The LM741 lifts the amplitude enough to drive the 2N3906.
The 3906 in turn will turn on the LED and buzzer as signal at the opto is made.
How do I attenuate the speaker volume?
How do I get the "sound" or will it amplify a "click"?

Bear in mind I know zip about electronics and am on the steeper side of the learning curve.

Cheers
Andrew

 

[duffy]

You have the right idea overall, but the specifics are bad. First off, how many watts do you want to drive the speaker with? Is it running off batteries?

If it's only a watt or so, and you want it to run on 4 AA batteries, then perhaps an LM386N amp and a small 4Ω speaker instead of that 741. If the drive power needs to be higher, there are other options...

Here's an attractive one -
**broken link removed**

18W into 2 channels, volume control, switch, terminals, runs on 12V, costs $10 - you can't even buy the parts for that.

It will make a "click" every time the opto flag cuts the light to the sensor - it will conveniently sound very much like the click from the reel.

If you would rather buy the sensor instead of taking a mouse apart, it's called a "photointerrupter", and there are many to chose from. Here's one with leads that might make mounting more convenient -
Digi-Key - OR562-ND (Omron Electronics Inc-ECB Div - EE-SX1088-W1)

Here's a link to the spec sheet for a different unit, there's a small schematic at the bottom that shows the output -
https://www.electro-tech-online.com/custompdfs/2009/02/en-ee_sh3_series.pdf

We can set those resistor values once we know what the power supply is.

Adding the LED is easy, there will be a 2N2222 transistor connected to that same output to blink the light, a cap and diodes on the base so it doesn't stay "on" when the shutter isn't moving.

First we need to figure out what it's going to be powered with. Got +12V on your boat you would want to run to it, or is this going to be batteries?

 

[Andrew Leigh]

Thanks Duffy

Required Wattage, no more than a medium to loud mobile phone ringtone, would that be 1W or so? Really nice looking amp by the way and great value, might use it anyway to amplify my iPod on the boat ... another project.

Great that it has a click sound.

I am going into the local components shop this a.m. and will see if they have a "photointerruptor", will buy one if they do as well as a 2N2222. Should have enough diodes, caps and the rest to complete the project.

Will be using a 7.2Ah 12V Gelled Cell as the power pack.

I have done some reading and found a 200 gain circuit on the LM386 datasheet which I have drawn as shown below, I have also added the LED but have no idea where to connect the other resistor and caps to stop the LED being permanently on.

I assume that the 10k pot is to attenuate the signal? We let you know which photointerrupter I get.

Cheers
Andrew

 

[Andrew Leigh]

Hi Duffy

I bought a sensor rather than wait for a mouse https://datasheet.digchip.com/513/513-05316-0-TCST-1103.pdf I hope this is suitable. If it is would you mind having a look at how best to integrate it into the circuit I posted above, assuming that is if the circuit is suitable.

I would assume that the sensor sends a signal when the path between the two sides is unobstructed?


Cheers
Andrew

 

[duffy]

That sensor will work just fine. Yes, the sensor sends a signal when the path is unobstructed, it turns the detector "on". Yes, the 10k pot is the volume control.

Here's your revised schematic. You had the LED backwards and the resistor was too low for 12V. I removed the 10µF cap from the LM386 because it won't need the gain of 200, added a power supply cap, changed a couple of the values to ones that are easier to find (a 220µf cap is a lot more common than a 250).

R6, C5 and D2 stop the LED from being on all the time so it will just blink once per interruption.

 

[Andrew Leigh]

Excellent, thanks a million.

I had posted more questions only to find that your latest post answered all but one of them so I rapidly deleted the post.

Reading another post on a LM386 application it was mentioned that the LM386 gets a little too warm at 12V and that the the additional voltage was wasted through heat, perhaps 9V was more appropriate. I could even run this on 6V would it make any difference?

Cheers
Andrew

 

[duffy]

You may want to use an LM386N-4 instead of an LM386N-1, it is designed to work with higher voltages - but the standby consumption on either of those devices is only around a tenth of a watt, so it really shouldn't be a problem.

It does not have a huge power output, it is only rated for about one watt - similar to a mobile phone ringtone. I suspect it's getting hot simply because people turn it up too loud, the higher voltage makes it easier to crank the volume, but the chip's not designed for it. Also - use an 8Ω speaker, not a 4Ω speaker. That's another way people get in trouble with this amp at 12V.

That circuit won't run well at lower voltages without changing several resistor values.

 

[Andrew Leigh]

Great,

almost finished the board layout already and am in the process of trying to get the neatest and most compact layout.

Cheers
Andrew

 

[Andrew Leigh]

Hi Duffy,

when you get a moment won't you check the following schematic. I have duplicated the circuit for two channels. I have also commoned the power supply and made allowance for the opto's to be off the main board.

Could the common supply cause other issues?

I think I only need a 3 pin connector for the opto as two of the pins are commoned?

Cheers
Andrew

 

[Boncuk]

Hi Andrew,

why do you mess around with electronics indicating a bite?

A very simple (non-electronic) way is attaching a small bell (used for cats to warn birds of them) to the end of the fishing rod.

Especially eels like to rock the rod when they bite. Barracudas also rock a lot and therefor I was generous and gave them one of my flightboots.

(Sea survival training at Homestead AFB, FLA)

Boncuk

 

[Andrew Leigh]

Hi,

these are very common for the type of fishing I am talking about.

We fish from the bank of a river / resevoir and will at times take the lines in +200m. The rods are then placed on stands and the wait begins. The rods are never hand held.

Many times fishing goes on through the night and it is impossible to man two rods 24/7. This is where the bite indicators come into their own, in the day the audible sound is a warning (not all reels have a ratchet to indicate the run off of line) of the fish taking interest or indeed a fish which has taken the bait and run. Although at night one can hear the audible warning the LED will alert one to which rod is getting attention. It can be pitch black at times.

Cheers
Andrew

 

[Boncuk]

Hi Andrew,

alright, here is another simple way for the bite alarm.

Route the fishing line over a second pivoting reel (one loop) and attach it spring loaded to the fishing rod.

If the fish starts running the reel will be pulled towards the end of the rod. Attach a fixed position micro switch to open or close if the reel touches it.

Boncuk

 

[Mickster]

Andrew,

what is the ultimate goal of this project? Is it to further an interest in electronics and proudly use something built by yourself, or to just "get" an electronic indicator?

The reason I ask is due to there being a plethora of electronic indicators already on the market, already tried and tested, waterproofed, compact and probably cheaper than the retail cost of individual components in your market.

The European angling scene is awash with electronic bite indicators with adjustable sensitivity/volume/tone, ranging from basic buzzers that are activated simply from the line taughtening and moving an arm, intermediate designs that are activated from the line passing over a roller and activating a magnet/reed switch or opto-interrupter setup, to multi-channel wireless indicators that transmit to a separate receiver and are triggered by the vibrations from the line passing over a sensatory wand.

The first example is only capable of registering a bite whilst the fish is taking line from the spool. The other examples are capable of registering bites not only whilst a fish is taking line away from the rod tip, but also when used in conjunction with some form of weight between the indicator and the reel, and can indicate bites when the fish makes a "run" toward the rod. In this situation, the bait/leger weight moves, the line slackens and the aditional weight triggers the indicator in the reverse direction.

Line-bites, where the fish just bumps the line, can often occur and result in a single trigger, so most indicators have a built-in latching function that triggers an LED for 30 seconds or so. This allows you to be ready, beside the correct rod, if the fish actually takes the bait and runs.

If you are designing an indicator for yourself or to market, take the above situations into consideration and think about a microcontroller setup, which will allow much more flexibility .... When used with multiple rods, there should be at least one method of differentiating between them and adjustable tone is preferred over visual identification, especially in daylight. At night, the visual (LED) option is considered an advantage since it offers an approximate position of the rod. Used in conjunction, the two can be quite powerful.

Adjustable sensitivity can also be quite useful in different weather/fishing conditions - a calm day on a lake can afford a much higher sensitivity than a windy day on a fast-flowing river, where each wind gust or current surge can result in false-triggers.

You may know most, if not all, of the above already...

 

[Andrew Leigh]

Hi Mickster,

you are 100% correct about the types out there on offer in the U.K. less so here in S.A. but that is not the point.

I have built a couple of projects all of which have cost me significantly more in financial terms. Have just completed a fridge thermostat which cost more than it should but will probably work better than a commercial unit as it is tweaked to my specific application. In the process I learnt about LED's, a comparitor, how to use a transistor to drive a relay and a little on simple power supplies.

The main goal is to learn and to get creative stimulus that I find impossible to get in my job.

Carp fishing here is done a little differently to the U.K. 95% of fishermen I see use a very simple coloured float attached loosely to the line after the rod and before it enters the water. This float is effectively the bite indicator, unless of course your reel is screaming for attention which leaves one in no doubt. At night a small glow stick is attached. The sophistication level of carp fishing here I believe is less so than in Europe.

I recently went on my first "boys only" carp fishing weekend and after viewing this primative, yet effective, float method I found myself making a "lager decision", that is, a boast of bravado after a few pints that I could do better. The people I went with have precious little so I reasoned that anything I came up with would most certainly be better than what they had. It would be nice to make up a lot of units (about 16 of them) and to give each fisherman two.

So it is to primarily learn but also to help others who cannot afford the real macoy.

I could not design anything, I rely heavily on people in forums to help, as have the people on this forum. The circuit that Duffy has come up with looks like it has great potential. From the looks of it the unit will click once for a predetermined advance, yet to be determined by the size of the pulley over which the line will run and the frequency of the spacings that will interupt the optoisolator.

The LED will blink in unison with the click, I will probably have a bypass switch to remove the LED from the circuit to save what little current it consumes during the day. As the speed increases so too will the frequency of the click hopefully resembling a scream free drag on a reel.

The lad's I wnet with will often fish through the night, sleeping next to their rods so this should work a treat.

Boncuk, if there is a loop around another reel how would one strike at the fish or have I misunderstood the arrangement. There also must be negligable resisitance, the fish must be able to remove line freely.


Thanks and Cheers
Andrew

 

[Andrew Leigh]

Bite Indicator ....... nearly there

Hi Duffy,

have breadboarded the project but I think either I have connected something wrong or some values need tweaking.

Diagnostics/B]
Apply power - Buzzer beeps once, LED light up and stays illuminated


Set Gain Pot to Min (interupt sensor slowly) - No sound DUH, LED dims slightly for a fraction of a second but not when beam is broken but when beam is restored .

Set Gain Pot to Max (interupt sensor slowly) - No sound DUH, LED dims slightly for a fraction of a second but not when beam is broken but when beam is restored.

Set Gain Pot to Min (interupt sensor rapidly) - No sound DUH, LED dims slightly for a fraction of a second but not when beam is broken but when beam is restored.

Set Gain Pot to Max (interupt sensor rapidly) - Nice clicking sound but much softer than anticipated, LED dims slightly for a fraction of a second but not when beam is broken but when beam is restored.

When in rest state the LED stays illuminated.

So could have connected something the wrong way but is probably unlikely as the circuit works.

Any ideas ..... ?


Cheers
Andrew

 

[duffy]

You have something connected wrong. That LED will not stay lit in that circuit. Sounds like the cap is bad, backwards, or shorted. Also check the pinout on the transistor, make sure you don't have the base swapped with the collector or something.