Control a thermal printer with Micro:bit

A thermal printer is a type of printer that uses heat to transfer ink or toner onto paper. Instead of using ink cartridges or toner cartridges, thermal printers use special thermal paper that has a coating of heat-sensitive material on one side. When the paper is passed through the printer, heat is applied to the coating, which causes the material to darken and create an image or text.

Thermal printers are widely used in many different applications, such as point-of-sale (POS) systems, label printing, and barcode printing. They are known for their speed, durability, and low cost of operation, as they do not require ink or toner. However, thermal paper is costlier than regular paper and the printout is not long-lasting as it fades with time.

There are two types of thermal printers: direct thermal and thermal transfer. Direct thermal printers use heat to activate the ink on the special thermal paper directly, while thermal transfer printers use a ribbon that is heated and pressed against the paper to transfer ink.

A thermal printer can be connected to a Micro:bit using an expansion driver card specifically designed for thermal printers. This card will provide the necessary interface and control signals to communicate with the thermal printer.

Once the thermal printer is connected to the Micro:bit, you can use the programming languages that Micro:bit supports to control the printer. This can include sending text or images to be printed, adjusting the print density and speed, and controlling other printer functions such as cutting the paper.

You will also need a library or an API that allows the Micro:bit to communicate with the thermal printer via the expansion driver card. This library will provide the necessary commands for sending data to the thermal printer, and handle any communication protocols required.

To use a thermal printer with a Micro:bit, you’ll need to have a basic understanding of programming and the Micro:bit platform, as well as knowledge of the specific thermal printer and expansion driver card you are using.

Purpose of this tutorial:

In this tutorial we will see how to send data from the Micro:bit card to a QR701 thermal printer: If you press button A on the Micro: bit card, the printer prints the word ‘Micro:bit card’.

To control a QR701 thermal printer with a Micro:bit, you will need to follow these steps:

1. Connect the QR701 thermal printer to the Micro:bit. Make sure that the connections are secure and that the correct pins are matched.
2. Install the necessary libraries or APIs for communicating with the thermal printer on your Micro:bit. This may include a printer-specific library or a general serial communication library.
3. Write the code to control the printer using the Micro:bit programming languages, such as MakeCode. The code should include commands to send text or images to the printer, adjust print density and speed, and control other printer functions such as cutting the paper.
4. Upload the code to the Micro:bit and test the printer’s functionality. Make sure that the text or images are being printed correctly, and that you can adjust the print density and speed as desired.
5. Make any necessary adjustments to the code, and repeat the testing process until the printer is working as desired.

Components required

Micro:bit card

The micro:bit is a small, programmable computer developed by the BBC for use in computer education in the UK. It features a 5×5 LED matrix, two buttons, and various sensors, and can be programmed using a variety of languages, including MakeCode, Python, and JavaScript. The device is intended to be used in classroom settings to teach children the basics of programming and computer science, but it can also be used for a wide variety of other projects and experiments.

GPIO card

A GPIO (General Purpose Input/Output) card for the Micro:bit is an expansion board that can be used to connect the Micro:bit to various sensors and actuators. The Micro:bit has a limited number of I/O pins, and a GPIO card provides more I/O pins to connect more devices.

A GPIO card typically connects to the Micro:bit via the edge connector on the bottom of the board, and provides additional I/O pins in a breadboard-compatible format. Some GPIO cards also include built-in components such as LEDs, buttons, and sensors, which can be used to add functionality to the Micro:bit without the need for additional components.

The Micro:bit GPIO card can be programmed using the Micro:bit programming environment, which is based on the block-based programming language, and also support micropython. The GPIO card can be used to control and read sensors, lights, motors, and other electronic devices.

QR701 thermal printer

The QR701 thermal printer is a compact and portable thermal printer that is typically used for point-of-sale (POS) systems, label printing, and barcode printing. It uses thermal printing technology, which means that it uses heat to transfer ink or toner onto paper.

Some of the features of the QR701 thermal printer include:

• High print speed: It can print up to 90mm/s, which is quite fast
• High resolution: It has a printing resolution of 8 dots/mm (203 dpi)
• Support for various paper widths: Can print on paper widths from 40mm to 82.5mm
• Support for various paper types: It supports paper types such as thermal paper, thermal label paper, and thermal tag paper
• Support for various languages: It supports various languages such as Chinese, English, Japanese, and French
• Small and lightweight: It is small and lightweight, making it easy to transport and use in various settings.

The QR701 thermal printer can be connected to a variety of devices such as computers, POS terminals, and microcontrollers, using various interfaces such as USB, serial, and Ethernet.

This printer is widely used in retail, warehouse, logistics and other industries. It can be used to print receipts, labels, and tickets, among other things.

5V-2A charger

A 5V-2A charger is a type of power supply that can be used to provide power to the QR701 thermal printer. The charger is typically a small, compact device that can be plugged into an electrical outlet to provide power to the printer.

The 5V-2A charger is necessary to provide a stable power supply to the thermal printer. The thermal printer requires a stable power supply to function properly and to avoid any damage to the internal components. The 2A part of the charger specification indicates that the charger can provide up to 2 amperes of current, which is sufficient to power the printer and keep its battery charged, if the printer has one.

Test plate

A test plate, also known as a prototyping plate or a breadboard, is a device that is used to build and test electronic circuits. It provides a convenient way to connect components such as resistors, transistors, and LEDs, without the need for soldering.

Connecting wires

Connecting wires are used to connect electronic components in a circuit. They are typically made of copper and are coated with insulating material to prevent electrical contact between the wires themselves or between the wires and other conductive materials.

Mounting

To perform the assembly, we connect:

• the VH pin of the printer to the (+) terminal of the charger

• the first GND pin of the printer to the GND pin of the Micro: bit board

• the second GND pin of the printer to the GND pin of the Micro: bit card

• the TR pin of the printer to pin P8 of the Micro: bit card

Makecode program

This is the program that prints data sent from the Micro: bit card to the printer.