1.but there are some garbage characters printed in my print receipt, like dots and a0, a1, etc.
--------What ESC commands do you use to print this reciept?
2.Also, while scanning the QR code, I am getting the message App won't run without Google Play services, which are not supported by your device.
-------M1 has google play services.Please give us the SN and build number in the settings.
Wether your app needs the GMS certification?