1. Feedback Speed Control Embedded Systems Interfacing

2. Overview Background Task 1 MATLAB ® Step Response Root Locus Task 2 Scaled Coefficients Task 3 Proportional-Integral Speed Control Task 4 Step Response for: Critically Damped Over Damped Under Damped

3. PWM/Motor Speed Labs ADC +5 VDC PWM +12 VDC +5 VDC PIC24FJ128 TD62003AP LM2907 V(speed)

4. Open-Loop Load-Speed Characteristics Speed Load

5. Block Diagram Internal To feedback.c PIC24FJ128 Darlington Driver, Motor and Freq-to-Volt

6. PID Controller Time-Domain Laplace-Domain of PI Controller PID

7. Stability Control Ratio Critically Damped

8. Control Algorithm

9. Task 1 – Step Response Analysis Within MATLAB ® Define A and B Define transfer Function Use step()

10. Task 2 – PID Gains Condition K1 = 1024  kK2 = b  K1 Under Damped Critical Damped Over Damped Unstable

11. Task 3 Within main( ) Initialization RD0 Timer 3 ADC Interrupts and Timer 3 Interrupt PWM ADC PMP then LCD LCD text on screen

12. Task 3 Within main( ) Endless Loop Wait for for semaphore == 1 Clear semaphore Calculate new output value using difference equation Write to PWM Update out(k+1), in(k+1), and in(k+2) Display Speed

13. Task 3 Within Timer 3 ISR Clear Interrupt flag Start sampling

14. Task 3 Within ADC ISR Get new speed reading and clear DONE Set semaphore Check for one-hundred passes (100 x 50ms = 5 s) If 100 passes then Toggle RD0 Calculate new reference = Step*D0 + Offset Reset pass count Else Increment pass count Clear ADC interrupt flag

15. Task 3 Download to project folder feedback.c peripherals.a (library archive) peripherals.h Create project and add all three files Add linker script Create heap

16. Open-Loop Load-Speed Characteristics Speed Load Closed Loop Open Loop

17. Task 4 Use Internal Reference Use MPLAB’s Data Monitor and Control Interface to Adjust K1 and K2 Capture Image on MSO and repeat for Critically Damped Over Damped Under Damped

18. Data Monitor and Control Interface

19. DMCI Configuration Right Click

20. DMCI Use Press Save after Dynamic Data Control is configured Press Halt Adjust Sliders Use Mouse Up arrow and Down arrow Press Start