ARTA, STEPS & LIMP
For qualified measurement of a loudspeaker you also need the direction diagram. Even using ARTA this is complex, but can be carried out automatically with the help of the turntable presented here.
In this project we will use a DC motor with encoder. Wim was so kind providing the software for the PIC. As the Motor is not able to draw more current from the driver IC (an Allegro A4970 FullBridge Driver) even when blocked, I decided against a current limiter function, for making the PCB design more easy and reliable.
The rest is quite straight forward: a 5V regulator and some capacitors for smoothening the power supply even the motor draws some more current.
The PIC provides an USB slave interface out of the Box and connections to the motor are made using standard terminals.
Please find the connection diagramm for the ARTA Turntable Module below: