Example code in WiFiDiscoveringServices not working on Arduino MKR WiFi 1010, found "\r\n" in serial input. #12
Description
Describe the bug
The example code for WiFiDiscoveringServices.ino has a bug. When user inputs a service type from prompt the input will contain "\r\n" and that causes the startDiscoveringService to not return any services.
Steps to Reproduce
- Start a mDNS service locallyband start for example a
_mqtt._tcpservice. - Run the example
WiFiDiscoveringServices.ino - Input "_mqtt" in the serial prompt.
Expected behavior
The user should be able to input any service name such as "_mqtt" or "_http" in the serial prompt and get an answer back with the service found.
Actual behavior
When user inputs "_http" or "_mqtt" in the serial prompt the mDNS service returns with nothing only showing this text, "Finished discovering services of type ".
Information
IDE: Platform.io version 3.4.3
Board: Arduino MKR Wifi 1010
OS: Windows 11
Perquisites: Run a mDNS service locally like this: "dns-sd.exe -R mqttb _mqtt._tcp . 1883"
Additional context
Found that this part in the example code, WiFiDiscoveringServices.ino, might hold the bug.
Variable serviceName will contain "\r\n" after user inputs service name to serial prompt and that causes the startDiscoveringService to not work properly.
void loop()
{
char serviceName[256];
int length = 0;
while (Serial.available())
{
serviceName[length] = Serial.read();
length = (length + 1) % 256;
delay(5);
}
serviceName[length] = '\0';
....
mdns.startDiscoveringService(serviceName, MDNSServiceTCP, 5200);
... .
}
I've fixed it with replacing the code with this instead.
void loop() {
String inputString = "";
while (Serial.available() > 0) {
delay(10);
char c = Serial.read();
inputString += c;
}
if (!mdns.isDiscoveringService() && inputString.length() > 0) {
// Remove newline
inputString.replace("\r\n", "");
// Convert string to char array
char charArray[inputString.length() + 1];
inputString.toCharArray(charArray, inputString.length() + 1);
mdns.startDiscoveringService(charArray, MDNSServiceTCP, 5200);
}