[Android] Increasing Label Darkness with ZD420: can't find ZebraPrinterLinkOs


I'm trying to increase the sharpness & darkness of shipping labels printed with my ZD420 printer via an Android app.

I found sample code for this in the docs here ( but when I try it, my code crashes when I call ZebraPrinterFactory.getLinkOsPrinter(connection). The error I get is:

"java.lang.NoClassDefFoundError: Failed resolution of: Lcom/fasterxml/jackson/databind/ObjectMapper;"

[ANDROID] Is it possible to pull paper back after a calibration through ZPL commands? ZQ520 Printer

I have 2 models of zebra printer being supported by the application: RW420 and ZQ520.

The RW420 has a nice feature of pulling the paper back by pressing a button on the printer, but the ZQ520 doesn't have this feature and I'm wondering if it is possible to have the printer pull the paper back in after a calibration using ZPL commands. We wish to avoid manually reseating the paper after the calibration process.

APPFORUM 2019: The Latest Features for Developers Using Android Oreo and Pie

From KitKat to Lollipop and Marshmallow to Nougat each version of Android changes the behaviour of how your applications work. Documentation of these changes is readily available for consumers but for app developers, detailed information on the implications of each version is less prevalent.