2/26/2015 Richard Kuo Assistant Professor Timer/WatchDog /RTC 2/26/2015 Richard Kuo Assistant Professor

Outline 6.0 NuMicro_Timer.ppt Timer/WatchDog/RTC Introduction Exercise Timers Lab. Periodic mode (smpl_Timer_LED) Lab. One timer Multiple counter (smpl_Timer_Counter) Lab. One timer Multiple modes (smpl_Timer_LCD) Exercise Timer Capture pin Lab. Ultrasonic Sensor module (smpl_Timer_SR04) Exercise Watch-Dog Timer Lab. Watch-Dog Timer (smpl_WDT) Exercise Real-Time Clock Lab. Real Time Clock (smpl_RTC) Homework : Car Parking Sensor

Timer Features Four 24-bit up-counting timer A prescaler (divider) for each Timer Selectable 5 clock source Four modes : one shot, periodic, toggle, continuous Timeout Period calculation Time out period = (Period of timer clock input) * (8-bit Prescale + 1) * (24-bit TCMP)

Nano100 Timer Clock Source

Nano100 Timer Block Diagram

NUC100 Timer Clock Source HIRC HCLK LIRC HXT

NUC100 Timer Block Diagram

Timer operation modes Example: TCMPR = 100 One-Shot mode Periodic mode Continuous Counting mode Interrupt 100 One shot Reset counter Periodic 100 Overflow 100 101 224-1 Continuous

smpl_Timer_LED volatile uint8_t ledState =0; void TMR1_IRQHandler(void) { ledState = ~ ledState; // changing ON/OFF state if(ledState) PC12=0; else PC12=1; TIMER_ClearIntFlag(TIMER1); // Clear Timer1 time-out interrupt flag }

smpl_Timer_LCD

smpl_Timer_SR04 Ultrasonic Sensor HC-SR04 VCC5 to VCC GND to GND GPB2 to Echo GPB4 to Trig

Ultrasonic Ranging Module SR04 Item Specification Working Voltage DC 5V Working Current 15mA Working Frequency 40Hz Max. Range 4 m Min. Range 2 cm Measuring Angle 15 degree Trigger Input 10 us TTL pulse Echo Output TTL level

Ultrasonic Sensor Waveform

Ultrasonic Ranging Module SR04 supply a short 10uS pulse to the trigger input to start the ranging, then the module will send out an 8 cycle burst of ultrasound at 40 kHz and raise its echo The Echo is a distance object that is pulse width and the range in proportion Equation : Distance = (Echo_Pulse [us] * 340/2 [Meter] ) / 1000 …… (Unit: mm) Example : Echo Pulse: 11245 us, Velocity of Sound: 340m/s Distance = (11245 * 340/2) / 1000 = 1911 (Unit: mm) over 60ms measurement cycle is suggested, in order to prevent trigger signal to the echo signal. Ultrasound Speed : V = 331.4 + 0.607 * T

Ultrasound Sensor Ranger Principle 。 Ultrasound Sensor Ranger Principle Ultrasound Sensor Ranging the distance by measuring the time from transmitting 40KHz wave to received 40KHz wave, Ultrasound Speed : V = 331.4 + 0.607 * T T : temperature C0 : speed at absolute zero degree Distance t: travel time from sound wave transmitted to the reflection received

WatchDog Timer 18-bit up counter 8 selections of time out period Support function: WDT interrupt WDT reset WDT wakeup

NUC100 WDT Clock

Watchdog controller Block Diagram

Watchdog Timer Interrupt & Reset signals

Windowed Watchdog controller Block Diagram

Nano100 WDT Time out Interval selection

Nano100 WWDT pre-scaler selection

NUC100 WDT Time out selection WTIS Interrupt Timeout Watchdog Reset Timeout WTR Timeout Interval for Reset (WDT_CLK=12MHz) WTR Timeout Interval for Reset (WDT_CLK=32KHz) 000 24 WDT_CLK (16 WDT_CLK) (24 + 1024) WDT_CLK (1040 WDT_CLK) 86.67us 32.5 ms 001 26 WDT_CLK (26 + 1024) WDT_CLK 90.67 us 34 ms 010 28 WDT_CLK (28 + 1024) 106.67 us 40 ms 011 210 WDT_CLK (210 + 1024) WDT_CLK 170.67 us 64 ms 100 212 WDT_CLK (212 + 1024) WDT_CLK 426.67 us 160 ms 101 214 WDT_CLK (214 + 1024) WDT_CLK 1.45 ms 544 ms 110 216 WDT_CLK (216 + 1024) WDT_CLK 5.55 ms 2080 ms 111 218 WDT_CLK (218 + 1024) WDT_CLK 21.93 ms 8224 ms `

smpl_WDT

RTC Features TLR=0x00093043 CLR=0x00120229 RTC counter A set of Alarm Time counter Calendar counter Day of week Leap year BCD format TLR=0x00093043 CLR=0x00120229 A set of Alarm Alarm and time tick interrupt Wakeup function 32KHz compensation

RTC Block Diagram INIR (0xA5EB1357) AER (0xA965) 512 RTC clock ≒15msec

RTC Example RTC sample code with driver RTC sample code Enable RTC and set date and time Date: 2009.1.19 Time:13.20.00 Enable alarm interrupt and set alarm date and time Alarm date:2009.1.19 Alarm Time:13.20.10 RTC sample code The same flow

Smpl_RTC

smpl_Timer_WDT_RTC

Car Parking Sensor

Important Notice ! This educational material are neither intended nor warranted for usage in systems or equipment, any malfunction or failure of which may cause loss of human life, bodily injury or severe property damage. Such applications are deemed, “Insecure Usage”. Insecure usage includes, but is not limited to: equipment for surgical implementation, atomic energy control instruments, airplane or spaceship instruments, the control or operation of dynamic, brake or safety systems designed for vehicular use, traffic signal instruments, all types of safety devices, and other applications intended to support or sustain life. All Insecure Usage shall be made at user’s own risk, and in the event that third parties lay claims to the author as a result of customer’s Insecure Usage, the user shall indemnify the damages and liabilities thus incurred by using this material. Please note that all lecture and sample codes are subject to change without notice. All the trademarks of products and companies mentioned in this material belong to their respective owners.