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rs485receiver
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added packet recognition and ping response

master
Jake 2025-09-11 01:41:32 +08:00
parent 01a1c6b8a3
commit 519871ee34
1 changed files with 79 additions and 3 deletions
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82
RS485Receiver.ino
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@ -12,6 +12,15 @@ Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);
#define DE_PIN 20
#define RE_PIN 10
#define THIS_ID 200
#define PING 0x01 // QUERY THE WORKING STATUS
#define READ_DATA 0x02 // READ DATA
#define WRITE_DATA 0x03 // WRITE DATA
#define REGWRITE_DATA 0x04 // QUEUES MOVES FOR ACTION COMMAND
#define ACTION 0x05 // TRIGGERS REG WRITE WRITES
#define SYNCWRITE_DATA 0x83 // SIMULTANEOUS CONTROL OF MULTIPLE SERVOS
#define RESET 0x06 // RESET TO FACTORY DEFAULT
void setup() {
// Initialize Serial1 for RS485 (TX=21, RX=9)
Serial.begin(115200);
@ -21,9 +30,7 @@ void setup() {
pinMode(DE_PIN, OUTPUT);
pinMode(RE_PIN, OUTPUT);
// Enable receive mode
digitalWrite(DE_PIN, LOW);
digitalWrite(RE_PIN, LOW);
SetModeReceive();
// Initialize OLED
Wire.begin(3, 4); // SDA=3, SCL=4
@ -66,6 +73,26 @@ void loop() {
display.println("Received:");
display.setCursor(0, 12);
display.setTextSize(1);
if (buffer[4] == PING) {
if (buffer[2] == THIS_ID){
sendPingResponse();
Serial.println("ME!");
display.print("!");
}
Serial.println("PING");
display.print("PING");
display.print(" ");
display.println(buffer[2]);
} else if (buffer[4] == WRITE_DATA) {
Serial.println("WRITE_DATA");
uint16_t position = (buffer[7] << 8) | buffer[6];
display.print("WRITE_DATA");
display.print(" ");
display.print(buffer[2]);
display.print(" ");
display.println(position);
}
for (int i = 0; i < count; i++) {
display.print("0x");
@ -73,6 +100,55 @@ void loop() {
display.print(buffer[i], HEX);
display.print(" ");
}
display.display();
}
}
void SetModeTransmit() {
digitalWrite(DE_PIN, HIGH);
digitalWrite(RE_PIN, HIGH);
delay(10);
}
void SetModeReceive() {
digitalWrite(DE_PIN, LOW);
digitalWrite(RE_PIN, LOW);
delay(10);
}
// Send a ping command to a specific servo
void sendPingResponse() {
uint8_t packet[6];
packet[0] = 0xFF; // Header
packet[1] = 0xFF; // Header
packet[2] = THIS_ID; // Servo ID
packet[3] = 0x03; // Length = instruction + address + checksum
packet[4] = 0x00; // NO ERROR
// Calculate checksum
uint8_t sum = 0;
for (int i = 2; i < 5; i++) sum += packet[i];
packet[5] = ~sum; // Checksum
// Send packet
SetModeTransmit();
Serial1.write(packet, sizeof(packet));
Serial1.flush();
SetModeReceive();
// if (PRINT_SENT_PACKETS) {
// Serial.print("Sent ping packet: ");
// for (int i = 0; i < 6; i++) {
// Serial.print("0x");
// if (packet[i] < 0x10) Serial.print("0"); // Leading zero for single-digit hex
// Serial.print(packet[i], HEX);
// Serial.print(" ");
// }
// Serial.println();
// }
}