Hi Guys
This is my first post here so please be gentle with me,lol.
I am building an electric fishing reel and my fishing mate plays around with Arduino so he has offered to help me set up the electronics using arduino boards.
I need to find a solution that will allow us to count the number of turns of the spool so that we can tell how much line we have out.
It would need to count both plus and minus directions so that when the counter reaches zero, we can have an auto stop function programmed to turn off the 12v DC motor.
I would like to use a magnet on the side of the spool with a sensor mounted into the reel frame to read the magnet every time it passes the sensor.
We will use an Arduino LCD screen for the readout.
Can anyone help out with some suggestions on how to build this counter and the bits and pieces that we will need.
Thanks.
Lance
I would use a hall sensor. Pretty cheap and easy. But in order for direction you need two. Space them not to far apart. That way, by looking at which of the two was high first, you know the direction.
But this is a forum for help, so the major input needs to come from you. I would start by making a schematic. Please don't make a Fritzing breadboard* mess! Just a simple hand drawing is way better. If you want to use
- If you want to use Fritzing, use the Schematic part.
Hi Septillion.
Thanks for your reply.
I have started playing with a generic digital counter that uses 2 hall sensors to get plus or minus counting depending on the direction that the spool is moving.
The problem is that every time the spool does a full turn, the magnet passes both sensors therefore it adds one and then subtracts one going past the second sensor so the counter effectively counts nothing every turn.( +1-1=0)
Rotate the spool in reverse and I get -1+1=0 regardless of how many turns the spool makes.
Most fishing reels that have counters use 1 sensor only to count plus & minus spool turns but I cannot work out how they are doing it.
I was hoping some one here may have some suggestions using arduino to sort this out.
You should not make one add and one subtract. You should look at them combined.
Hall A detects first and after that hall B detects => increase
Hall B detects first and after that hall A detects => decrease
aussie123:
Most fishing reels that have counters use 1 sensor only to count plus & minus spool turns but I cannot work out how they are doing it.
Without extra hardware, impossible...
aussie123:
I was hoping some one here may have some suggestions using arduino to sort this out.
That's a bit rude! Didn't I just do that? :
Hi,
Welcome to the forum.
Please read the first post in any forum entitled how to use this forum.
http://forum.arduino.cc/index.php/topic,148850.0.html
This may help;
https://playground.arduino.cc/Main/RotaryEncoders
Tom..
aussie123:
It would need to count both plus and minus directions so that when the counter reaches zero, we can have an auto stop function programmed to turn off the 12v DC motor.
Does the motor operate on payout *and * retrieve? If so, you may only need one sensor. Just use the motor direction signal to choose count up/down.
Thanks Tom and Septillion.
dougp the motor will continually run in forward while the spool is stopped or even turning in reverse which is why I need to count off the spool revolutions and not the motor shaft itself.
I did find some quadrature sensors online tonight which may do the job so I have to have a close look at those to see if they may be suitable.
Most quadrature are just two mechanical switches. You can do the same magnetically with to hall sensors. Probably easier to mount. But idea kind of stays the same.
What do you mean with "the motor will continually run in forward while the spool is stopped"? What is the purpose of that motor?
septillion:
Most quadrature are just two mechanical switches. You can do the same magnetically with to hall sensors. Probably easier to mount. But idea kind of stays the same.What do you mean with "the motor will continually run in forward while the spool is stopped"? What is the purpose of that motor?
Hi Septillion
This 12v DC motor is the drive motor for winding the line up.
The fishing reel has a drag system on the spool which allows the spool to slip/stop on the shaft while the motor is driving the spool shaft through a gearbox.
The slipping spool stops the line from breaking under load when the fish is fighting and wanting to pull line off the spool, hence why I need to count the spool revolutions and not the motor shaft revolutions.
The main reason I am looking for a single sensor setup is to cut down on the machining costs and also simplify the setup and installation on these reels.
Either options look like they will work now, we just have to work out which option will suit my application the best and then work out how to do the code for them.
Thank you for your help and suggestions too, it is greatly appreciated, especially when I have never attempted something like this before.
aussie123:
Hi Septillion
This 12v DC motor is the drive motor for winding the line up.
The fishing reel has a drag system on the spool which allows the spool to slip/stop on the shaft while the motor is driving the spool shaft through a gearbox.
The slipping spool stops the line from breaking under load when the fish is fighting and wanting to pull line off the spool, hence why I need to count the spool revolutions and not the motor shaft revolutions.
Understood! I'm not a fisher, just an engineer 
aussie123:
The main reason I am looking for a single sensor setup is to cut down on the machining costs and also simplify the setup and installation on these reels.
You might save on machining (although can't imagine it to be that hard) but it no way makes it simpler. From a single pulse sensor it's just impossible to tell the direction. From two close together, easy.
You might get away with using 2 sensor and magnets in a pastern but that just sounds to complicated.
More expensive equipment might use some sort of (capacitive) linear encoder like in digital calipers but doesn't seem suitable for hobby stuff.
I thought using the motor direction as the counting direction (and direction only) a smart idea but if the shaft can slip an thus also move in the opposite direction of the motor it is of no use.
Optical sensors can be used too. There may even be a larger variety of optical sensors so you can find a package that suits your application. You can get 'fork' style ones that detect an object passing between the two arms or a single-sided one that can detect something like a dot of white paint on the spool.
Have you ever opened up a mechanical mouse? The old ones with a ball? They use fork optical sensors to detect the direction of rotation and count slots in the little tiny wheels inside.
Hall sensors are probably also available in 'encoder' styles. I've never looked. I suggest you look for one that packages two sensors close enough together that they both see the magnet at the same time. Then you just look for which one saw it 'first' to determine the direction of rotation.
Once you have two adjacent sensors wired to two Arduino inputs then the regular encoder.h library will work, even if they are just looking at a single magnet or dot of paint.
Thanks guys, your help has given us a few ideas to look in to.