I want to authenticate UID on RFID with my mysql database which I have registered UID before, which later Arduino get response from php if UID is valid or not.
But when I do tapping, uid is not readable by php
if my source code is correct please help
how to get arduino to know UID on RFID valid according to database.
After getting the authentication results I can continue the advanced functionality.
I need his help to complete my final assignment
thank you
This suggests that you are using a Mega, with 4 hardware serial ports.
SoftwareSerial mySerial(8,9);
This suggests that you have not bothered to read the SoftareSerial documentation, and which pins you can, and can NOT use, on the Mega.
Of course the presence of this line suggests that you need to SERIOUSLY read up on the capabilities of the hardware you have AND use the native capabilities instead.
You attempt to read the RFID card ONCE, when setup() runs. If the card is not present, nothing ever happens.
Why are you not trying, even though you WOULD fail, to read the card in loop()?