Instructables

janw

  • Date JoinedDec 22, 2009
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Orangeboard

Bot13982 years ago
Thaxx for subbing any reasons?
janw (author)  Bot13982 years ago
Because I like your instructables and you followed me.
do u provide the program of the pill dispenser? is it included in the pdf?also..whats the frequency of the quartz crystal to be used?
please reply as soon as possible..am a student and had taken ur version as a project because it inspired me:)
thanking you
angel
janw (author)  rainbowangel2 years ago
There is no program any;ore. I lost it due to a computer crash and I never wrote a new one.

The quartz crystal is 32768Hz one as specified in the datasheet of the DS1307
thanks...is there any way i can get the program?
robot13983 years ago
my new instructable
http://www.instructables.com/id/Laser-powered-burglar-alarm/
plz vote
winsdream4 years ago
Hi janw,

I've a few questions to ask you regarding your medication dispenser.

1) so does it mean that each stepper motor controls 1 drum, therefore you need 7 stepper motors to control 7 drums?

2) how do you control the speed of the stepper motors?
janw (author)  winsdream4 years ago
Hi winsdream,

I did use 7 stepper motors so 1 for each drum. Those are 15step stepper motors but you can use motors with more steps.

To contole the speed, I used 7 L293D-ic's (so one for each motor) in combination with the microcontroller. The microcontroller sends pulses to the L293D-ic and that one makes the motor spin 1 step for each pulse. THe delay time between the pulses is with a simple wait statement in the program.
winsdream janw4 years ago
Hi janw,

Is there a simpler way to control the speed of the stepper motor? For example using Pulse Width Modulation method?
Sorry for the trouble caused because it's a student project and resources limited.
Thanks, Winsdream.
janw (author)  winsdream4 years ago
You can connect the steppers directly to a microcontroller but there are some problems with that:

1) you won't have enough pins
2) the output of your microcontroller is not high enough (only 5V and a few mA) so you need something to get them to 12V and a reasonable amount of Amps.

So the easiest way I figured out was to use the 74HCT238 to select the motor (it only need 3 pins for 8 motors) and the L293D as the motor driver so that the motor runs on 12V
doctorbee4 years ago
Hi janw, I was wondering how much did your medication dispenser cost? Also--have you patented your design? It could be amazingly beneficial to the senior community. Thanks, db
janw (author)  doctorbee4 years ago
It costed me about 40Euro so thats not very expensive.