Go Down

Topic: Connecting thingssss (Read 386 times) previous topic - next topic

larryd

#15
Aug 25, 2019, 07:05 pm Last Edit: Aug 25, 2019, 07:07 pm by larryd
OP image:


A self loading teeter-totter feeding container might work nicely.




No technical PMs.
If you are asked a question, please respond with an answer.
If you are asked for more information, please supply it.
If you need clarification, ask for help.

Shokii

yes i have tried searching the net and most results are ads of a specific product.


this is what i have in mind. sorry, my sketchup app expired. i plan to use only 1 arm for servo and have it rotate for 180 degrees only. so as the hand rotates, the sensor will measure weight of the feed currently in the tube before discharging it. and in the design so that the FSR wont be damage, on the end of the tube that connects the container and the sensor, i plan to put a flexible yet sturdy enough so that the feed won't fall down. it looks like the second pic. its like frills in my imagination

Shokii

i can't seem to find what you are talking about. i mean the self loading teeter totter. do you some photos or somethin?

again, im very sorry for the poor quality of the images. im still just a student and this project would my undergraduate thesis. please bear with me and please don't get discouraged :(

larryd

#18
Aug 25, 2019, 09:39 pm Last Edit: Aug 25, 2019, 10:27 pm by larryd
Something similar to this:



One feed per rotation/tilt.


'Cutout' determines feed per serving.


No technical PMs.
If you are asked a question, please respond with an answer.
If you are asked for more information, please supply it.
If you need clarification, ask for help.

Shokii

i have manage to create a block diagram for the system. please correct if me if there is something wrong.. please please please help me. i'm about to propose tomorrow and i don't have a design yet.

PLEASE HELP!

Shokii

pleeeaasee? anyone? please help me :(

wvmarle

That FSR idea is never going to work: how are you going to ensure that the whole weight of the tube (or even the whole contraption) is carried by the FSR? So nothing else that holds it up, no other support points, etc. All that messes up your weight measurement.

Besides, other than being cheap, an FSR is pretty hopeless for accurately measuring weights. That's what load cells are used for.

So that's why this is not normally done like that.

When dispensing something by weight, it's the RECEIVING end that is weighed: the container the product falls into. That you CAN reliably weigh. So you would need a buffer container - which you weigh, and where the fish feed first drops into, and when you have enough weight you tip that into the fish tank. If you need more than the container can hold, feed multiple batches.

The other way is to use a proper dispenser, e.g. a screw, so you can accurately control the volume of the product dispensed. Works quite well for liquids and most powdery/granular products, if your fish feed is pellets it should work. Rotate more for more food (use either a stepper, or regular DC motor with encoder attached to it).
Quality of answers is related to the quality of questions. Good questions will get good answers. Useless answers are a sign of a poor question.

larryd

#22
Aug 26, 2019, 06:01 am Last Edit: Aug 26, 2019, 06:03 am by larryd
"The other way is to use a proper dispenser, e.g. a screw, so you can accurately control the volume of the product dispensed. Works quite well for liquids and most powdery/granular products, if your fish feed is pellets it should work. Rotate more for more food (use either a stepper, or regular DC motor with encoder attached to it)."

Yes, easy to make, use a gear or stepping motor to turn drill bit.





No technical PMs.
If you are asked a question, please respond with an answer.
If you are asked for more information, please supply it.
If you need clarification, ask for help.

Shokii

both of the solutions are amazing. i got confused when reading it for the first time but as i read it over again, i started to visualize the point and principle of the two. if i go with option number 1 with the buffer container, any ideas on where to put it or what would be the best position? and if i may add, i realized i need to have a ventilator so that the feed can avoid moisture.

thank you so much for answering. :) im going to research a few things for the design

wvmarle

if i go with option number 1 with the buffer container, any ideas on where to put it or what would be the best position?
A convenient place... that allows you to easily drop your feed in it, do the weight measurement, and then empty it into the fish tank.

That's up to you to decide!

Actually depending on the feed used I'd prefer to go without buffer, and let the time the screw runs (or the number of rotations it makes) be your measure for amount of feed dispensed. As long as you're within some 10% variation the fish will be perfectly happy.
Quality of answers is related to the quality of questions. Good questions will get good answers. Useless answers are a sign of a poor question.

Shokii

Actually depending on the feed used I'd prefer to go without buffer, and let the time the screw runs (or the number of rotations it makes) be your measure for amount of feed dispensed. As long as you're within some 10% variation the fish will be perfectly happy.
you also mentioned that i can control the volume of the product dispensed. how that does wok? i mean is there some mathematical explanation for this?

wvmarle

With a screw what you dispense IS volume. That volume then relates to quantity/weight, which is easiest found by a simple calibration.

Do understand how the principle works!
Quality of answers is related to the quality of questions. Good questions will get good answers. Useless answers are a sign of a poor question.

Shokii

thank you bro. i really appreciate it. i think i understand the principle, more or less. but just to be sure, please enlighten me for some things. i don't have enough sleep so i am having a trouble for relating the volume and the mass of the feed given..

larryd

#28
Aug 26, 2019, 03:31 pm Last Edit: Aug 26, 2019, 03:39 pm by larryd
You dispense for a period of time (example 1 seconds) then measure how much weight/volume was deposited.

Try 2 second, 3 seconds, 4 seconds, 5 seconds, . . .

Record in a table or graph in Excel.

Use lookup table in Arduino or use 'linest' to get formula of graph, use formula in Arduino.




No technical PMs.
If you are asked a question, please respond with an answer.
If you are asked for more information, please supply it.
If you need clarification, ask for help.

Shokii

how do i measure the volume if the device is design once the the feed is dispensed, it will go straight to the water?

Go Up