Timers Chapter 10 Timers The 68 HC 12

Timers Chapter 10

Timers • • The 68 HC 12 Programmable Timer Output Compares Input Capture Pulse Accumulator Timing Interrupt Service Routines A Circular Queue Data Structure Keypad Interfacing Using Interrupts

Timers (cont. ) • Pulse Train Using Interrupts • Measuring the Period of a Pulse Train Using Interrupts • The Polaroid Ultrasonic Transducer – An Ultrasonic Tape Measure

Timer Counter

Timer System Control Register

Setting the timer count time

68 HC 11 Timer Registers

Timers • • The 68 HC 12 Programmable Timer Output Compares Input Capture Pulse Accumulator Timing Interrupt Service Routines A Circular Queue Data Structure Keypad Interfacing Using Interrupts

Pulse Train Example

Timers • • The 68 HC 12 Programmable Timer Output Compares Input Capture Pulse Accumulator Timing Interrupt Service Routines A Circular Queue Data Structure Keypad Interfacing Using Interrupts

Input Capture

Timers • • The 68 HC 12 Programmable Timer Output Compares Input Capture Pulse Accumulator Timing Interrupt Service Routines A Circular Queue Data Structure Keypad Interfacing Using Interrupts

Pulse Accumulator

The 74 C 922 16 -Key Encoder Connect pin 12 to PT 7/PAI instead of PJ 7

Pulse Accumulator on a 68 HC 11

Timers • • The 68 HC 12 Programmable Timer Output Compares Input Capture Pulse Accumulator Timing Interrupt Service Routines A Circular Queue Data Structure Keypad Interfacing Using Interrupts

Timing Interrupt Service Routines Traffic Lights Using Real-time Interrupt

Copy TRAFFIC. WHP to TRAFFIC 2. WHP

Add: Load TRAFFIC 2. WHP TEST. SETUP TEST

Timers • • The 68 HC 12 Programmable Timer Output Compares Input Capture Pulse Accumulator Timing Interrupt Service Routines A Circular Queue Data Structure Keypad Interfacing Using Interrupts

A Circular Queue empty Containing 2 values

Timers • • The 68 HC 12 Programmable Timer Output Compares Input Capture Pulse Accumulator Timing Interrupt Service Routines A Circular Queue Data Structure Keypad Interfacing Using Interrupts

Timers (cont. ) • Pulse Train Using Interrupts • Measuring the Period of a Pulse Train Using Interrupts • The Polaroid Ultrasonic Transducer – An Ultrasonic Tape Measure

Pulse Train

Timers (cont. ) • Pulse Train Using Interrupts • Measuring the Period of a Pulse Train Using Interrupts • The Polaroid Ultrasonic Transducer – An Ultrasonic Tape Measure

Timers (cont. ) • Pulse Train Using Interrupts • Measuring the Period of a Pulse Train Using Interrupts • The Polaroid Ultrasonic Transducer – An Ultrasonic Tape Measure

Polaroid Ultrasonic Ranging System

Waveforms of Ultrasonic Ranging System

Exercises