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Accessory Shield User Manual
is 5000mv / 1024 = 4.88mv. When the AD value is 1, it corresponds to the output
voltage 4.88mv.
Accessory Shield provides an on-board 10k adjustable potentiometer with the
maximum adjustable output voltage of 3.3V. When the development board is
powered supply by 3.3V, the ADC output value is in the range of 0 – 1023. For 5V
power supply, the ADC resolution is 4.88mv, and the AD value corresponding to
3.3V, the maximum output voltage, is 3300 / 4.88 = 676, so the ADC output value is
in the range of 0 – 676 in this case.
Operation and phenomena:
Perform program compiling and uploading, and then click the button
the serial port monitor of Arduino IDE. If the program is running properly, the monitor
will display the current ADC value. When the potentiometer is adjusted, the
outputted sample value will change too, as the figure shows below.
2.2.3 Buzzer
In applications, active buzzer can be directly connected to the rated power supply to
work properly. But passive buzzer, as well as electromagnetic loudspeaker, requires
an audio output circuit to work with. The buzzer we use here is an active buzzer,
which can either perform simple frequency sound with DC power source, or play
simple music with AC power source.
Operation and phenomena:
Perform program compiling and uploading to the board. If the program is running
well, you can hear the buzzer play some simple music.
2.2.4 RGB LED
RGB LED use PWM function to control the brightness generated respectively by
th
V1.1.6, March 10
2015
Waveshare
to start
9
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