Keywish Hummer-Bot-1.0 Instruction Manual page 40

In Arduino, analog voltage can't be output, only 0 or 5V digital voltage value, we can use high
resolution counter and the duty cycles of the square wave modulation method to encode a specific level of
analog signal. The PWM signal is still digital, because at any given time, the full amplitude of DC power
supply is either 5V (ON) or 0V (OFF). The voltage or current source is added to the analog load with a ON
or OFF repetitive pulse sequence. When the DC power supply is added to the load, the power supply is on,
otherwise the power supply is off. As long as the bandwidth is enough, any analog value can use PWM to
encode. The output voltage value is calculated by the on and off time. Output voltage = (turn-on time / pulse
time) * maximum voltage. Fig.2.4.6 shows the corresponding voltage to the pulse change.
Arduino UNO possess 6 PWM pins, namely digital interfaces 3, 5, 6, 9, 10, 11, and we select 5, 6, 9, 10 as
the motor control IO, the connection is shown in Figure .2.4.7.
The following table shows the correspondence between L298N and Uno board:
Figure .2.4.6 Relation between Pulse and Voltage
L298N
IN1
IN2
IN3
IN4
Arduino Uno
D6
D10
D5
D9
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