Thanks for the explanation, this explains a lot. One more question if you will:
Without a resistor to limit the base current, a large base current may flow and damage the device.
Would it be possible to get around this by use PWM to activate the transistor instead of a simple digital HIGH? This way the voltage and current could be better controlled to avoid a potential large base current?
While I plan to follow the suggestion by @reivilo, and use add-on boards can be purchased with all the required circuit already in place, but I’m curious to know if the above is a potential solution. Thanks!
Thanks for this suggestion! It gave me the idea that maybe a whole package could be found instead of cobbling together parts outside of an IC. Something like this
The “vibration motor circuit” in the link is shown in the picture, the motor is driven by a FET, with a diode and a capacitor connected in parallel to the motor for noise suppression.
I think it can be connected directly to the XIAO port.
Driving the transistor PWM without a base resistor does not change the situation because the current is not limited during the HIGH period of PWM.
Hi there,
these are the spec’s , not enough drive from a xiao directly.
Product Description
Feature:
1. Using high quality 1027 mobile phone vibration motor, the vibration effect is obvious.
2. MOS amplification drive, can be directly controlled by the digital port, can control the vibration strength of the motor through PWM.
3. This module can easily convert electrical signals to mechanical vibration.
4. Suitable for the production of vibration‑sensitive interactive products, wearable smart device vibration reminders, etc.
5. Compatible for Mega2560 and particularly suitable for DIY projects.
Spec:
Item Type:Vibration Module
Rated Voltage: 5.0VDC
Working Voltage: DC 3.0 - 5.3V
Rated Speed: 9000RPM
Rated Current: 60mA
Starting Current: 90mA
Starting Voltage: DC 3.7V
HTH
GL PJ
you may want to look up the Parkinson’s “Glove” it uses similar tech. I have a friend who wants me to make a pair for her. So i’m lurking looking at the info.
PJ