I have attached below the circuit to the project that I am developing.
Is their a problem with the connections I have made?
Do I need to connect something to ground? Any other problems that you would like to point out?
Specifications of components:
Vibration motor:
Type: 0834
Material: iron
Size: 8 x 3.4mm Approx, wire 15mm(L)
Rated voltage : 3.0V DC
Rated current: 70mA Max
Rated rotor speed: 12000±2500RPM Min
Operating environment: -20℃～+60℃
Save environment::-30℃～+70℃
If you are just starting, you should draw out the circuit using conventional circuit symbols on paper and include a picture of it here. The Fritz diagrams have rightly a bad reputation because important detail is blurred and obscured. E.g. it is impossible to see the pin markings on the Uno board.
To me, it looks like there is a number of problems:
The diode is in an odd place. it should be reversed across the motor and the capacitor (if needed) in parallel with it.
The pinout for the 2N2222 appears reversed from what I can see.
Edit:
You should also include the code you are going to use.
OP's picture:
Include a link to the pro Mini you are going to use. Hopefully it is clear what regulator it uses. Your battery is 3.7 volt and there may be an issue there. It may be you have to put a diode in series with the battery to drop the voltage and then connect it to the 3.3V terminal of the Arduino instead.
Don't power the motors through the tiny (<150mA) regulator of the ProMini.
Connect motor(+) directly to batt(+).
Same for the emitters of the 2N2222 transistors.
Connect them directly to batt(-), not via ProMini ground pins.
For full saturation of the 2N2222 transistors (max motor power), base current should be 10% of collector current.
Lower the 1k resistors to 330ohm.
10n across the motors is more than enough.
Try to avoid pin13. That pin could change state during bootup.
Leo..
The conventional diagram is not only better readable, it's clearly correct. The Fritzy is clearly incorrect, even though many components are ambiguous to what they even are (such as those blue things - I guess that are the capacitors?).
The Arduino's regulator is best not used to power motors (not even a single one). The stall current of a single motor is probably too much.
Better connect them directly to the battery - you will have about 0.6V drop over the transistor anyway! So a full battery (4.2-4.3V) provides a bit higher voltage but that doesn't matter for most motors and you anyway have the PWM control.
For the Pro Mini: would it be safe to power it at a bit higher voltage on the Vcc pin? The processor won't have a problem with it, it's rated to handle up to 5.5V. Don't know about other on-board components.
Also you suggest on directly powering the motors through the battery. Well, in that case can the battery that I have purchased handle 6 vibrational motors together? I can't use multiple batteries because I want to keep the project small.
So... 70 x 6 mA for the motors, plus 50 mA for the Arduino (probably less as it's a Mini so pretty barebones) makes 470 mA.
So battery size needed is 470 mA x 4 hours / 0.7 (effective charge) = 2,700 mAh.
That's a high capacity 18650 battery, or a battery like this one from Adafruit.
TomGeorge:
I know you can get 3.3V Pro Mini, but the link the OP provided made no mention of 3.3V
hardik311095:
Are extra resistor needed to protect the motor from direct connection from battery?
No.
Basic wiring is battery pos - motor - transistor - battery neg.
Furthermore: you won't blow up those motors with a little extra voltage. You're going to regulate them anyway (PWM), so they get pulsed, and that way the effective current is brought down to whatever you need it to be to get them up to the speed you want to go.
I would really appreciate your help, I am stuck so bad, please help me in my first project.
