Keyestudio ESP32 Manual page 100

ESP32 Starter Kit
//set the pin connecting with button to input
pinMode(res,INPUT);
pinMode(add,INPUT);
pinMode(subtract,INPUT);
for(char b=0;b<4;b++){
DigitalTube.clearBit(b);
}
}
void
loop(){
DigitalTube.displayFloatNum(item);//Digital tube displays item value
int
red_key = digitalRead(res);
int
yellow_key = digitalRead(subtract);
int green_key = digitalRead(add);
if(green_key == 0){
item++; //operate to add 1, item = item + 1
delay(200);
}
if(yellow_key
==
item--;
delay(200);
}
if(red_key
== 0){
item = 0;
delay(200);
}
if (item > 9999) {
range)
item = 0;
}
}
4. Test Result
After connecting the wiring and uploading code, press green button to add 1, yellow to minus 1, and red to reset. Press
the button and hold it, and the displayed value will keep adding or reducing.
8.5.16 Project 15: Responder
1. Description
This programmable responder inputs and receives signals through Arduino development board and a group of buttons,
and it judges the correctness of answers via a LED. It is a good object to exercise students' reaction ability and draw
their attention to questions. If the answer is correct, the respondent obtains a lot scores.
Moreover, it simplifies teachers' manipulation of question-grabbers and cuts answer clutters. It may even stimulate
students' interests in learning.
96
//DigitalTube.clearBit(0 to 3); Clear bit display.
0){
//operate to reduce 1, item = item - 1
//return to zero when greater than 9999(excessing the
//Red button is the reset button
//Yellow button is minus 1
//Green button is plus 1
Chapter 8. Arduino Tutorial
(continued from previous page)
display␣