Page 12 of 16
Note GPIO lines used have been changed from 1 and 2 to 12 and 13 to avoid strapping pin.
Page 254
void setup() {
Serial.begin(9600);
Serial1.begin(9600, SERIAL_8N1, 12, 13);
Serial1.setTimeout(30);
}
void loop() {
char buffer[100];
Serial1.write("Hello World\n");
int len = Serial1.readBytes(buffer, 100);
buffer[len] = NULL;
Serial.printf("\nreceived data: %s\n", buffer);
delay(1000);
}
Page 255
void setup() {
Serial.begin(9600);
Serial1.begin(9600, SERIAL_8N1, 12, 13);
Serial1.setTimeout(30);
}
void loop() {
char buffer[100];
Serial1.write("Hello World\n");
if (Serial1.available()) {
char byte;
byte = Serial1.read();
Serial.print(byte);
}
delay(10);
}
Page 257
int count;
char buffer[100]={0};
void recieveData(void){
int nr=Serial1.readBytes(buffer,100);
buffer[nr]=0;
};
void setup() {
Serial.begin(9600);
Serial1.begin(9600, SERIAL_8N1, 12, 13);
Serial1.setTimeout(5);
Serial1.onReceive(recieveData);
}
void loop() {
Serial.print(count++);
Serial.println(buffer);
buffer[0]=0;
Serial1.write("Hello World\n");
delay(2000);
}
Page 258
Note change the start of setup to:
Serial.begin(9600);
delay(2000);
Serial.begin(9600);
to setup to force some ESP32s to change baud rate after upload and before calling loop.
void setup() {
Serial.begin(9600);
delay(2000);
Serial.begin(9600);
Serial1.setTxBufferSize(256);
Serial1.setRxBufferSize(1024);
Serial1.begin(9600, SERIAL_8N1, 12, 13);
Serial1.setTimeout(30);
int n = 1000;
char SendData[n];
for (int i = 0; i < n; i++) {
SendData[i] = 'A';
}
SendData[n - 1] = 0;
Serial1.flush();
unsigned long s = micros();
Serial1.write(SendData, n);
s = micros() - s;
Serial.printf("\nt= %f\n", s / 1000.0);
Serial.flush();
}
void loop() {
delay(1000);
}
Page 259 - created by adding end on page 259 to previous program
Note change the start of setup to:
Serial.begin(9600);
delay(2000);
Serial.begin(9600);
to setup to force some ESP32s to change baud rate after upload and before calling loop.
void setup() {
Serial.begin(9600);
delay(2000);
Serial.begin(9600);
Serial1.setTxBufferSize(256);
Serial1.setRxBufferSize(1024);
Serial1.begin(9600, SERIAL_8N1, 12, 13);
Serial1.setTimeout(30);
int n = 1000;
char SendData[n];
for (int i = 0; i < n; i++) {
SendData[i] = 'A';
}
SendData[n - 1] = 0;
Serial1.flush();
unsigned long s = micros();
Serial1.write(SendData, n);
s = micros() - s;
Serial.printf("\nt= %f\n", s / 1000.0);
Serial.flush();
char RecData[n+1];
int nr = Serial1.readBytes(RecData,n+1);
RecData[nr + 1] = 0;
Serial.printf("%s\n", RecData);
Serial.printf("%d %d\n", nr, sizeof(SendData));
}
void loop() {
delay(1000);
}
Page 258
Note change the start of setup to:
Serial.begin(9600);
delay(2000);
Serial.begin(9600);
to setup to force some ESP32s to change baud rate after upload and before calling loop.
void setup() {
Serial.begin(9600);
delay(2000);
Serial.begin(9600);
Serial1.setTxBufferSize(2048);
Serial1.setRxBufferSize(512);
Serial1.begin(9600, SERIAL_8N1, 12, 13);
Serial1.setTimeout(30);
int n = 1000;
char SendData[n];
for (int i = 0; i < n; i++) {
SendData[i] = 'A' + i / 40;;
}
SendData[n - 1] = 0;
Serial1.flush();
unsigned long s = micros();
Serial1.write(SendData, n);
s = micros() - s;
Serial.printf("t= %f\n", s / 1000.0);
delay(3000);
char RecData[n+1];
int nr = Serial1.readBytes(RecData,n+1);
RecData[nr + 1] = 0;
Serial.printf("%s\n", RecData);
Serial.printf("%d %d\n", nr, sizeof(SendData));
}
void loop() {
delay(1000);
}
Page 264
Note change the start of setup to:
Serial.begin(9600);
delay(2000);
Serial.begin(9600);
to setup to force some ESP32s to change baud rate after upload and before calling loop.
void setup() {
Serial.begin(9600);
delay(2000);
Serial.begin(9600);
Serial1.setTxBufferSize(2000);
Serial1.setRxBufferSize(130);
Serial1.begin(115200, SERIAL_8N1, 12, 13);
Serial1.setPins(12, 13, 5, 4);
Serial1.setHwFlowCtrlMode(UART_HW_FLOWCTRL_CTS_RTS, 10);
int n = 1000;
char SendData[n];
for (int i = 0; i < n; i++) {
SendData[i] = 'A' + i / 40;
}
SendData[n - 1] = 0;
Serial1.write(SendData, n);
char RecData[2000];
int nr = 0;
int nt = 0;
Serial1.setTimeout(1);
do {
delay(100);
nt = Serial1.readBytes(&RecData[nr], sizeof(RecData) - nr);
nr = nr + nt;
Serial.printf("%d %d\n", nt, nr);
} while (nt != 0);
RecData[nr + 1] = 0;
Serial.printf("%s\n", &RecData[1]);
Serial.printf("%d %d\n", nr, sizeof(SendData));
}
void loop() {
delay(1000);
}
Page 269
int presence() {
Serial1.updateBaudRate(9600);
Serial1.write(0xF0);
char byte;
Serial1.readBytes(&byte, 1);
Serial1.updateBaudRate(115200);
if (byte == 0xF0) return -1;
return 0;
}
void writeByte(int byte) {
char buf[8];
for (int i = 0; i < 8; i++) {
if ((byte & 1) == 1) {
buf[i] = 0xFF;
} else {
buf[i] = 0x00;
}
byte = byte >> 1;
};
Serial1.write(buf, 8);
Serial1.readBytes(buf, 8);
}
char readByte(void) {
char buf[8];
for (int i = 0; i < 8; i++) {
buf[i] = 0xFF;
}
Serial1.write(buf, 8);
Serial1.readBytes(buf, 8);
char result = 0;
for (int i = 0; i < 8; i++) {
result = result >> 1;
if (buf[i] == 0xFF) result = result | 0x80;
}
return result;
}
void setup() {
Serial.begin(9600);
Serial1.begin(115200, SERIAL_8N1, 12, 13);
}
void loop() {
Serial.printf("\n%d\n", presence());
writeByte(0xCC);
writeByte(0x44);
Serial.printf("%d\n", presence());
writeByte(0xCC);
writeByte(0xBE);
char data[9];
for (int i = 0; i < 9; i++) {
data[i] = readByte();
}
int t1 = data[0];
int t2 = data[1];
int temp1 = (t2 << 8 | t1);
if (t2 & 0x80) temp1 = temp1 | 0xFFFF0000;
float temp = temp1 / 16.0;
Serial.printf("temp =%f\n", temp);
delay(2000);
}
