Auto Pill dispenser / Pet Feeder Project

Thread Starter

Crakkers

Joined Feb 2, 2017
19
Hi I need help with a school project that my teacher cant help me with!

I wish to make an auto pill tray. Its a bit like one of those auto cat feeders.

imagine a bowl split into 7 segments
imagine the bowl rotates 1/7th of a complete rotation, once per day
imagine the bowl rotating below a fixed cover that has an opening the size and shape of one of the segments

Thats my project!

i am thinking about a stepper motor to drive the bowl a precise amount of degrees (1/7th of a circle) I think I need a motor driver / controller too. I'd like to have a buzzer to sound when its time to take the pills that needs to be switched off by the person when they have taken the pills.

So basically, for example at 8 AM the bowl rotates into place and a buzzer sounds until a person hits the reset button. 24 hours later the cycle repeats.

BUT, i dont know what to buy and how to connect it together.

Can you please help / tell me what to buy and join up?

Thanks

Crakkers
 

dl324

Joined Mar 30, 2015
10,731
Oh, I thought this was a help forum for people who want to learn about electronics, not one for bad comedians!
I'm serious. Bad ideas are bad ideas.

I've been the custodian for a dozen cats and none of them would self medicate. Some would let me put the pill in their mouth and hold it closed until they swallowed. I had to use a pill popper on one because he'd spit it out before I could hold his mouth closed if I didn't.

With that information, you can choose to pick a more realistic project. Otherwise, turn it into a fish feeder and forget the alarms and intervention by a person. They have feeders that will do a week, maybe two.
 

SamR

Joined Mar 19, 2019
2,108
I've been the custodian for a dozen cats and none of them would self medicate.
Uh, Dennis read it again...

"I wish to make an auto pill tray. Its a bit like one of those auto cat feeders."

He's not trying to dose the cat... Just dispense the pill.
 

ElectricSpidey

Joined Dec 2, 2017
1,142
Do you expect someone to design this entire project for you?

If you are looking for some ideas to start with I would say…

Can you glue some Neodymium magnets to this divided bowl?

If so I would start with 7 of those glued so they could trigger a sensor of sort, maybe a hall effect switch to stop the bowl at the proper place after a 24 hour timer starts the cycle, and starts a buzzer at the same time.

The timer should run continually, and have some kind of interface such as a dry contact or open collector, that triggers every 24 hours.

Rotating display motors are available that can drive a lazy Susan type of system. The electronics for driving and stopping the motor, starting the buzzer…etc, would not be overly complicated.

Of course in 5 seconds someone will post here with the advice to learn how to code and just use a micro controller…and of course that is a reasonable solution, but I often wonder how many projects never get done, because the only help they ever get is being told to learn how to code.

Designing a project like this is not overly difficult, but it does take some time to plan, and test before actually building, so be prepared to do plenty of work.

Best of luck…
 

Picbuster

Joined Dec 2, 2013
998
Hi I need help with a school project that my teacher cant help me with!

I wish to make an auto pill tray. Its a bit like one of those auto cat feeders.

imagine a bowl split into 7 segments
imagine the bowl rotates 1/7th of a complete rotation, once per day
imagine the bowl rotating below a fixed cover that has an opening the size and shape of one of the segments

Thats my project!

i am thinking about a stepper motor to drive the bowl a precise amount of degrees (1/7th of a circle) I think I need a motor driver / controller too. I'd like to have a buzzer to sound when its time to take the pills that needs to be switched off by the person when they have taken the pills.

So basically, for example at 8 AM the bowl rotates into place and a buzzer sounds until a person hits the reset button. 24 hours later the cycle repeats.

BUT, i dont know what to buy and how to connect it together.

Can you please help / tell me what to buy and join up?

Thanks

Crakkers
The most simple way is to use switches.
if (time) { rotate(int position)} // this will rotate until n switches are passed
// in your case position=1
// Timer = 24H x 3600 seconds // derived from RTC
// disadvantage you don't know which part of the bowl is selected.
// use a light code system to overcome this 3 ldr's and one led ( 000 001 010 011 100 101 111)
// now you are able to move to code eq 011 ( change the rotate(int position) function.
// no empty detection
Simple and quick however; the mechanical part is not that simple. Blocking on particles, play in the mechanical construction effects from moisture.

Picbuster
 

Thread Starter

Crakkers

Joined Feb 2, 2017
19
Hello everyone,

Thanks for the help so far. In answer to a few points and for clarification.

I am doing a Product Design course, where the challenge is to model / design / make a prototype product. The bowl part etc is the styling part of the product which I am working on alone. The "guts" of it are the electronics. I am NOT doing an electronics course - there is a big difference. So in answer to one question; do I expect someone to design my project for me, well maybe, but only in terms of the electronics; there is not time to do both parts of the project.

All I am after is good insight as to what bits to buy to prototype this up; the simpler the solution the better in my eyes, so I had thought of a motor controlled by a pic, but I am confused as to what bits to actually buy from all my research to date. To get a motor to turn in a controlled way is a starting point, but unless I can make that first start, I wont be able to progress.

I like the sound of the display motor and magnets, but again dont know what to buy to make a start to control the motor.

BTW, Im not trying to kill cats - the projects has nothing to do with animals!

So, If any detailed help can be given I'd be very grateful

Thanks in advance.
 

LesJones

Joined Jan 8, 2017
2,638
I think using a low voltage geared motor to rotate the bowl is simpler than using a stepper motor. Mount the bowl on top of a disk with 7 equally spaced notches around it's edge. Mount a micro switch so that it's contacts open when the lever on the micro switch drops into one of the notches. Connect the micro switch in series with the power to the motor. Arrange for another set of contacts in parallel with the micro switch contacts to close every 24 hours just long enough for the motor to rotate away from the notch. the disk will then continue to rotate until it reaches the next notch. A plug in timer could be used to trigger the short pulse. I use one plug in timer to open and close curtains and another to feed hedgehogs in the garden every evening. For these the timer just switches on for 2 minutes each time. For the curtains once in the evening and once in the morning. For feeding the hedgehogs just once at dusk. If you used this method you would need the on time to be long enough for the buzzer to be powered. I use PIC microcontrollers for both of these devices but I think you could manage with a few transistors, resistors and capacitors and a small SCR to latch the buzzer on until it was reset by the user.

Les.
 

Thread Starter

Crakkers

Joined Feb 2, 2017
19
I think using a low voltage geared motor to rotate the bowl is simpler than using a stepper motor. Mount the bowl on top of a disk with 7 equally spaced notches around it's edge. Mount a micro switch so that it's contacts open when the lever on the micro switch drops into one of the notches. Connect the micro switch in series with the power to the motor. Arrange for another set of contacts in parallel with the micro switch contacts to close every 24 hours just long enough for the motor to rotate away from the notch. the disk will then continue to rotate until it reaches the next notch. A plug in timer could be used to trigger the short pulse. I use one plug in timer to open and close curtains and another to feed hedgehogs in the garden every evening. For these the timer just switches on for 2 minutes each time. For the curtains once in the evening and once in the morning. For feeding the hedgehogs just once at dusk. If you used this method you would need the on time to be long enough for the buzzer to be powered. I use PIC microcontrollers for both of these devices but I think you could manage with a few transistors, resistors and capacitors and a small SCR to latch the buzzer on until it was reset by the user.

Les.
I like the look of this but TBH dont really understand it - sorry!

I see you are in lancashire, I am in Wirral. I could ask if we could pay your travel expenses if you were prepared to come to my school to help one day?
 

danadak

Joined Mar 10, 2018
4,057
Something like this -




This happens to use capacitive sensors on wheel.



Another variant.


Rotary encoders (shaft position).




Regards, Dana.
 
Last edited:

LesJones

Joined Jan 8, 2017
2,638
Hi danadak,
Your pictures look like you are showing a quadrature encoder system. What I was suggesting was much simpler as it does not need to provide direction information. The system I suggested just worked by the motor rotating the notched disk until the micro switch detected a notch. A short pulse to the motor (Long enough to move it away from the notch but not long enough to reach the next notch.) then made it continue to the next notch. An optical sensor could be used instead of a micro switch.

Les.
 

Thread Starter

Crakkers

Joined Feb 2, 2017
19
I'm not sure which part you don't understand. It it the concept of the disk with 7 notches and the micro switch ?

Les.
I understand the concept and I understand the micro switch aspect. Being quite visual I like to see sketches rather than descriptions.

I get how it will move incrementally with the notch and switches, but how does it go for the 24 hour period?
 

LesJones

Joined Jan 8, 2017
2,638
If you used a plug in timer when the power was switched on to you unit you could generate the short pulse. This could be as simple as a small relay with a capacitor in series with it's coil that was connected across your DC power supply. In your case you would have to have the timer output on for as long as you wanted the buzzer to sound. I would think a few hours would be enough but you could go up to 23 hours and 59 minutes. This is because it is the transition from power off to power on that generates the pulse to start the motor. The only thing that requires power for more than a minute or so (The time taken for the disk to move one position.) is the buzzer. An alternative to a plug in timer would be to use a 12 volt one such as this.

Les.
 

Thread Starter

Crakkers

Joined Feb 2, 2017
19
If you used a plug in timer when the power was switched on to you unit you could generate the short pulse. This could be as simple as a small relay with a capacitor in series with it's coil that was connected across your DC power supply. In your case you would have to have the timer output on for as long as you wanted the buzzer to sound. I would think a few hours would be enough but you could go up to 23 hours and 59 minutes. This is because it is the transition from power off to power on that generates the pulse to start the motor. The only thing that requires power for more than a minute or so (The time taken for the disk to move one position.) is the buzzer. An alternative to a plug in timer would be to use a 12 volt one such as this.

Les.
Thanks gain, I think Im getting it now, thanks for the link, that helped.

By plug in time do you mean this? for example?
 

ElectricSpidey

Joined Dec 2, 2017
1,142
As to the elecronics…

24 hour timer…provides a pulse to 2 SCRs
One SCR turns on the motor.
One SCR turns on the buzzer.
Whatever method chosen to detect position shorts the motor SCR stopping the motor.
The buzzer continues to buzz until the pill taker presses a button. (shorting the buzzer SCR)

I think a micro switch would work well, and possibly a reed switch and magnets.

I would look around on Amazon and such to find a 24 hour timer that can be used with the low voltage that you will use to drive the motor.
 
Top