Weight change sensor?

Hello everyone,

I am a newbie, but I have done a fair bit of reading and researching about Arduino programming and motor controlling and I think with some help from you I am ready to start my project which is basically an electric fishing reel to be used for automatic jigging.

The idea is based on programming the motor to let the fishing line drop down to the bottom then start hauling it in cycles at different speeds and distances, and when fish strikes, it hauls the line all the way up to the boat !

my question is, is there a sensor that can sense the weight change on the line to trigger the hauling process? For example, if I program the sensor for the normal operating weight on the line to be between 0.5kg and 0.75kg, and anything above that will be considered as a catch and will start the hauling process.

There are few automatic jigging machines in the market which I got the idea from, but way too expensive "over $3000", and also on a commercial fishing scale which is not my field. And they work the same way I explained above "sensing the extra weight on the line", so I am confident that there is a sensor of that kind, but unfortunately I failed to find it so far !

It would be great to get an answer so I can go ahead and start the project.

I still have some more questions about the project, but I thought I would start with this one, and then take it from there.

Thank you in advance.

A load cell (probably a "bending beam load cell") would be used to detect weight (force) and you would want an HX711 module to interface with it.

If you were using a motor to wind the string onto a reel you could detect something pulling on the string by watching how much current the motor was using. Typical current sensing solution is the ACS712.

If your jigging machine is using some kind of pole with it you could detect the bending of the pole with a flex sensor.

OneGoal:
Hello everyone,

I am a newbie, but I have done a fair bit of reading and researching about Arduino programming and motor controlling and I think with some help from you I am ready to start my project which is basically an electric fishing reel to be used for automatic jigging.

The idea is based on programming the motor to let the fishing line drop down to the bottom then start hauling it in cycles at different speeds and distances, and when fish strikes, it hauls the line all the way up to the boat !

my question is, is there a sensor that can sense the weight change on the line to trigger the hauling process?
For example, if I program the sensor for the normal operating weight on the line to be between 0.5kg and 0.75kg, and anything above that will be considered as a catch and will start the hauling process.

There are few automatic jigging machines in the market which I got the idea from, but way too expensive “over $3000”, and also on a commercial fishing scale which is not my field.
And they work the same way I explained above “sensing the extra weight on the line”, so I am confident that there is a sensor of that kind, but unfortunately I failed to find it so far !

It would be great to get an answer so I can go ahead and start the project.

I still have some more questions about the project, but I thought I would start with this one, and then take it from there.

Thank you in advance.

Do some research on accelerometers. You could probably see a vibration, jerk on the line easier.

Chuck.

Chagrin:
A load cell (probably a “bending beam load cell”) would be used to detect weight (force) and you would want an HX711 module to interface with it.

If you were using a motor to wind the string onto a reel you could detect something pulling on the string by watching how much current the motor was using. Typical current sensing solution is the ACS712.

If your jigging machine is using some kind of pole with it you could detect the bending of the pole with a flex sensor.

Chagrin,

A current sensor sounds like a great idea.
I could use “if” logic to program it to stay in normal operating condition if the current on the motor is between two numbers “allowing for different conditions”, and if the current goes beyond the programmed number, then a hauling process starts.

The challenge will be writing the script as I am still new, but I will try my best and am sure you guys will help.

Another thing I thought about was a load cell attached to a pulley with the line going through it and program it to stay normal between two number and when it goes beyond that with the line tension it will start hauling !

But with the load cell or with the bending sensor, the sea condition will be a challenge because the boat will be rocking up and down and will give false readings to the sensor and make it haul the line without a fish.

A current sensor might be easier as it is a matter of programming as opposed to keep playing with hardware !

Please have a look at this video if you have a minute, this will make it clearer.
P.S fast forward to 1:50 to see the graphic operating pattern if you find it boring to watch the whole thing.

Cheers

chucktodd: Do some research on accelerometers. You could probably see a vibration, jerk on the line easier.

Chuck.

Hi Chuck,

I have watched few videos on accelerometer operation with arduino, and it seems to be too sensitive for the job and also more complicated to program than a current sensor !

A current sensor might do the job if I can apply the theory to it. I don't need it to be super sensitive anyway, for example lets say I have current values from 1minimum to 10maximum and if I can program the motor to operate normally between "current value1 and current value4" so the variation in water condition and boat movement will be allowed for, and anything above current value4 will tell the motor to haul the line all the way up to the boat.

it is easier said than done for me as I am still learning, but I will try to play with it and see how far I can get. meanwhile please feel free to correct me if I overlooked something or misunderstood any technical points !

Cheers

Fish don't weigh much in water :) so you need to detect the thrashing, not the weight.

I think the best approach would be to use a load cell with HX711 as recommended by Chagrin. It could be either a bending beam type or a conventional type supporting a pivoted rod.

if you arrange that the short rod pivots against a spring, I wonder if you could use one of these as a cheap vibration sensor. Alternatively consider using an accelerometer as recommended by chucktodd.

I think measuring motor current may be able to detect when the sinker rises off the bottom, but that's all and only when the motor is winding the reel.

Archibald: Fish don't weigh much in water :) so you need to detect the thrashing, not the weight.

I think the best approach would be to use a load cell with HX711 as recommended by Chagrin. It could be either a bending beam type or a conventional type supporting a pivoted rod.

if you arrange that the short rod pivots against a spring, I wonder if you could use one of these as a cheap vibration sensor. Alternatively consider using an accelerometer as recommended by chucktodd.

I think measuring motor current may be able to detect when the sinker rises off the bottom, but that's all and only when the motor is winding the reel.

Hi Archibald,

Having the sinker off the bottom and motor winding the reel is exactly what I need, because I want to use it for jigging (pulling the line up and down to tease the fish with fake bait), and I will not be using a rod for the line, it will be running through a set of pulleys from one side of the boat to the other side and the pulleys will be hanged from poles across the boat, so the theory is to drop the line till it reaches the bottom then lift it few feet off the bottom and start the jigging process by making the motor reel up and down till it senses an extra load which will change the current and trigger the hauling process .... small fish don't bite on the hooks I use as it is too big for its mouth, and the minimum weight of fish that strikes is 0.75kg, and u will be surprised how strong it is in the water even though it doesn't weigh much but when it pulls on the line it is quite powerful and enough to cause a load on a motor,,,, from experience with a Japanese electric fishing reel (Diawa 750) and catching with it, a fish of that weight is enough to make a 12v DC motor change sound, that's why im thinking more about the current sensor !

I have googled the other suggested sensors but don't seem to find a convincing example to use it for my purpose ! but it will not hurt to try.

Cheers.

how did you go with your fishing reel build? I see you started it a few years ago. I am about to build the same thing. I think the weight sensor is going to be the best way of determining the status. I think it will need to have an adjustable min load value and a max load value. The min load value will need to be set so that variables such as sinker weight, current and reeling it in without a fish etc do not set it off. Anything above the min value is fish on and it will need to reel it in at full speed. Im going to use a stepper motor as it needs to know how far it goes down to come back to the top exactly. Any weight load greater than the max load setting and the motor will need to act in reverse which acts as a sort of variable drag so that the line doesnt snap.

Hey.. I haven’t done a weight setup yet, but I’m planning one. Here are my ideas..

The “rig” on springs. The amount of rig movement per weight is found through measuring. Ie. 1lb moves rig 1 inch. Then... use light trip sensors. 1/2 mounted to non-moving measured weight milestones, the other 1/2 of sensor mounted to moving rig.

Could maybe do multiple point measurements. Like rig passed point one, and tripped point 2, so 2lbs.