Maple Lesson 05 - The button PWM controls LED brightness

Objective LED has only two states on and off in other experiments, now we will use the button to control LED brightness light gradually and gradually out Equipment Microduino-CoreSTM32 Microduino-CoreSTM32 is an ARM development board using STM32F103CBT6 chip. It use special Upin7 interface, the size is similar with a coin and fully compatible other Microduino modules. Other hardware equipment Breadboard Jumper one box Breadboard one piece LED Light-emitting diodes one 220ohm resistor one Button one USB Data cable one File:Maple-lesson3All1.jpg 600px Schematic File:Maple-lesson5-pwm schematic.jpg 600px Buttons are used with internal pull-up and external pull-down, and then connect to the digital I/O port D0-D13. PWM must use following I/O port. 0,1,4,11,12,14(A0),15(A1),16(A2),17(A3),18(SDA),19(SCL),20(A6),21(A7)。 File:Maple-lesson5-Setup1.jpg 600px Program int led=4; int butt0n_1=2; int butt0n_2=3; int n=0; void setup () { pinMode(butt0n_1, INPUT_PULLDOWN); //Set to internal pull-down pinMode(butt0n_2,INPUT_PULLUP);//Set to internal pull-up pinMode(led,PWM);//This pin only can be set to port 0,1,4,11,12,14(A0),15(A1),16(A2),17(A3),18(SDA),19(SCL),20(A6),21(A7) for PWM. } void loop() { int up =digitalRead(butt0n_1); //Read port 2's state int down = digitalRead(butt0n_2); //Read port 7's state if (up==HIGH) { n=n+5; if (n>=255) { n=255; } } if (down==LOW) { n=n-5; if (n<=0) { n=0; } } pwmWrite(led,n*160); //Using PWM control the output of port 11, the range of the variable n is 0-65535 delay (300); } Result One button makes the LED brightness progressively decreasing, and another button makes LED brightness incremental. File:Maple-lesson5-Result1.jpg 600px Video