A humanoid arm + hand prototype made of balsa wood
Everywhere it's specified that A.Due has same pin layout with Arduino Mega, so you can use Mega's Sensor Shield on Due.
Project showcase by tolgadurudogan
On this sample I would like to explain why PID-control should be used for speed controls and how the direction can be inverted.
Project tutorial by tolgadurudogan
A model rocket that guides itself autonomously.
Project in progress by Cole Purtzer
A robotic tower crane made out of Lego Technic, Arduino boards, 3D printed parts, off-the-shelf DC gear motors, and addressable RGB LEDs.
by Tart Robotics
Balancing an inverted pendulum on a cart with a DC motor. A perfect project for studying mechanical engineering and feedback control theory.
Project showcase by zjor
Approach is correct but may lead burning the components if implemented without control.
Transistors have forward gain coefficients (hfe) and passes amplified base current (Ib) by this value at collector (Ic).
Ic = hfe * Ib
And base current is typically Ib = (Vb - VBE) / Rb
(VBE = 0.3 V for Ge-, and 0.7 V for Si-transistors - typically)
So on this example;
Vb(Ard.Pin.2) = 5V, Rb = 1k and if VBE = 0.7V -> Ib = 4.3 mA
and if hfe = 50 as a typical value Ic becomes 215 mA, which may bur a LED.
Refer to transistor datasheets for the parameters.
At first, thanks for your comments.
"...in the bridge circuit the bottom 2 transistor should be NPN not PNP as the current is in reverse..."
It's not a must actually... Perhaps you considered another path for reversing current. My considerations was either T1A-Motor-T1B or T2A-Motor-T2B paths.
"...putting 4 diodes between collector and emitters will protect the transistors from spikes back EMF from the motor induction..."
I think if transistors are selected at suitable ratings, effect of spikes would be negligible during normal operation. Anyway such spikes by induced coils of DC Motors, appear mainly when motor is stopped. But it's a transient case and takes very short while that can be handled by transistors.
Thanks for interesting, and hopefully all of them will fit well on your implementations.
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