A piezo device can… (Put an X in the box next to your selection)

…produce a sound from an electrical signal

…produce an electrical signal from a vibration or sound

X

…do both

X

…produce a tone for an alarm

X

…create rapid, precise motion for optics in scanning instruments

X

…driving elements for micro-dosing and nanopumps

…energy-harvesting power source for implantable devices

…all of the above

Analogwrite() is a method of setting the values of single PWM output pin. The scale on analogwrite () is between 0-255 and the duty cycle is always switched on. The analongwrite at 50% duty cycle is half of the time. Tone()  generates the square waves that can be specified under the frequency on a pin. The duration is specified in the tone and waves remains continued until the next wave of notone arrives. At the time only one tone can be generated with the different pin. If the tone is adjusted on the same pin, then all the set frequency will be different. Multiple and different pins at same pitch can be generated before calling Tone(). The syntax example is tone (pin, frequency) and tone (pin, frequency, duration)

X

FLASH

X

SRAM

X

Fuses

X

EEPROM

Stack Pointer

X

AVR General-purpose Registers

CPU

SRAM

FLASH

ADC

Watchdog Timer

All of the above

X

CPU, SRAM, FLASH and ADC

Crystal Oscillator

External Clock

Low-Frequency Oscillator

X

Internal Calibrated 8MHz RC divided-by-8

X

Fuse

Software-writable Register

Both a Fuse and a Software-writable Register

X

Fuse

Software-writable Register

Both a Fuse and a Software-writable Register

X

Power-on

X

Brown-out

Clock Failure Detector

X

Watchdog Timer

Status Register Overflow Flag

X

External Pin

The mechanism of clock failure detection is interlinked with the enabled CFD fuse in the extended fuse byte. The operation of CFD in case of 128kHz internal oscillator will enable the automatic process of CFD. The clock failure detector will enable the user to monitor the low power crystal oscillator and the external clock signal. If the CFD monitor or the XOSC clock fails, then the process will switch to the safe clock. This switching process favors the use of 128k internal RC in the watchdog time and clock failure detector instead of crystal oscillator as well as external clock.