thermalprinter

Thermal Library driver for Android Things

This driver exposes a UART interface to a serial thermal printer. This printer can print text with a variety of text styles. Additionally, it can print bitmaps and barcodes.

This driver works with the thermal printers from Adafruit, such as the CsnA2 Mini Thermal Printer. When you power on your device, press the button in order to get a printout of device information. Take note of the firmware version. This driver supports firmware v2.68 and above.

The thermal printer requires an external power supply. It cannot be powered by the developer board.

At this moment the driver has only been tested on the Raspberry Pi 3 and the imx7.d.

NOTE: these drivers are not production-ready. They are offered as sample implementations of Android Things user space drivers for common peripherals as part of the Developer Preview release. There is no guarantee of correctness, completeness or robustness.

How to use the driver

Gradle dependency

To use the thermalprinter driver, simply add the line below to your project's build.gradle, where <version> matches the last version of the driver available on jcenter.

dependencies {
    compile 'com.google.android.things.contrib:driver-thermalprinter:<version>'
}

Sample usage

// import the Thermal Printer driver
import com.google.android.things.contrib.driver.thermalprinter.ThermalPrinter;

// Start thermal printer.
mThermalPrinter = new ThermalPrinter("UART0");

// Make sure to call mThermalPrinter.close() in the onDestroy() method in your activity

// Start printing text.
mThermalPrinter.enqueue(new TextJob().printText("Hello World"));

// Print stylized text.
mThermalPrinter.enqueue(new TextJob()
    .justify(CsnA2.JUSTIFY_CENTER)
    .setDoubleHeight(true)
    .printText("Hello World"));

// Print a barcode.
mThermalPrinter.enqueue(new BarcodeJob()
    .setBarcodeHeight(60)
    .printBarcode("GOOGLE", CsnA2.UPC_A));

// Print a bitmap
mThermalPrinter.enqueue(new BitmapJob().printBitmap(bitmap));
// Feed several lines afterward
mThermalPrinter.enqueue(PrinterJob.feedLines(3));

// Close Thermal Printer driver
try {
  mThermalPrinter.close();
} catch (IOException e) {
  Log.e(TAG, "Unable to close thermal printer driver", e);
} finally {
  mThermalPrinter = null;
}

License

Copyright 2018 Google Inc.

Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.