New but asking for help with MC / PWM ?

[Lycan]

Hello All,

Ok I am old but stubborn, so am going to follow this issue through regardless, my question / problem is as follows :

What is the most simplistic way to design a circuit board that will supply current to a small pager motor at varied intervals & duration.

IE : Run pager for 1 sec on 1 sec off, 3 sec interval then repeat, then on for 5 sec off for 2 sec and then continue to repeat that entire cycle pattern.

The cycling pattern will never be altered so can you program a small mc then place that chip on a board with power / motor and will run as is ? This is worded so basic its embarrassing but I self taught myself everything about 3D printing and design in autocad & solidworks so I am persistant enough to learn.

Finished deign needs to be as small and simplistic as possible.

Any and all help greatly appreciated if anyone has the time to spend enlightening me.

Steve

 

[Lycan]

Ps : Worst case scenario even if it runs on for 5 - 7 sec off for 3 and just repeats that sequence if that enables a simpler design.

Steve

 

[Arouse1973]

Hi Steve, welcome to EP.
Yep micro-controller would be the simplest. What current do you need to supply to this motor? What voltage does the motor require?
Adam

 

[Lycan]

Hi Adam and Thanks for taking the time out to reply,

Power supply is intended to be 3v at this point, supply a pager motor with the following specs :

• Designed for 3V nominal operation, giving 920RPM drawing 100mA. At stall, you get over 0.49in*oz or 35.28gm*cm of torque
• or as per link https://solarbotics.com/product/gm15/
• Ideally based on my initial post, I am hoping that the completed unit will run for minimum 2 Hrs on that power supply before requiring battery change.

For now I am primarily interested in just getting the basic`s set up, then can hopefully look at motor alternatives, along with the possibility of different power supply to keep the unit running longer - but no doubt that requires additional electronics to reduce voltage supply so it doesn't burn out.

Functional yet cheap is the aim as have to build multiple units, alternatively can go more expensive is the long term gains ( durability ) are worth it.

Will a complete board like this work https://solarbotics.com/product/19035/ its a Adafruit Pro Trinket, really just guessing here.

Thank you once again in advance.

Steve

 

[Lycan]

Back Again,
Was thinking the adafruit pro trinket, combined with the rechargeable LiPoly backpack with a 3.7v 2500 mah battery may possibly mean I could have the whole unit enclosed and use the uSB port for programming and charging ??

Steve

 

[Arouse1973]

Hi Steve. This little PCB will do the motor control but will not charge the battery. The USB connector is for programming only. Although you maybe able to get a +5 Volt output from it which you could possibly connect to a battery charger IC (special one needed for Lithium batteries). I haven't looked at the circuit diagram for it yet to check this is possible. Using the Arduino environment is probably the best way to go at the moment. With some basic code and a few extra components you could be up and running in an hour, it's that quick to develop on these things. Then the motor drive could just be a simple transistor and heat-sink if one is needed.
Adam