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Thermal printer module for Tessel

Support for the A2 micro panel thermal printer module for Tessel.

This module is based on xseignard's thermalprinter package

Important Information Specific to Module

  • Needs a seperate 5v - 9V, 2A power supply. The Tessel can't power this. 9V is faster.
  • You can do a test print by holding the printer button while powering.


npm install tessel-thermalprinter
  • A, B, D ports only. C doesn't support UART yet.
  • Wire it up so: Ground (printer) to Ground (Tessel: Pin 0), RX (printer) to RX/G1 (Tessel: Pin 8) add pics later


var tessel = require('tessel');
var thermalprinter = require('tessel-thermalprinter');
var printer = thermalprinter.use(tessel.port['A']);
printer.on('ready', function(){'Printer ready!');
        .printLine("we're printing with")
        .printLine(' TESSEL! ')
  'Printer finished!');

For the example you'll need to add a api key. You can get one here on their website.



# printer.setMaxPrintingDots( maxPrintingDotsValue, callback() )
_Set the max printing dots (0-255). Default: 7 (( 7 + 1 ) * 8 = 64dots). Unit: ( n + 1 ) * 8dots

According to section 5.2.9 of the datasheet: "The more max heating dots, the more peak current will cost when printing, the faster printing speed. The max heating dots is 8 * ( n + 1 ).""

# printer.setHeatingTime( heatingTimeValue, callback() )
Set the heating time (3-255). Default: 80 (800µs). Unit: 10µs.

According to section 5.2.9 of the datasheet: "The more heating time, the more density, but the slower printing speed. If heating time is too short, blank page may occur."

# printer.setHeatingInterval( heatingIntervalValue, callback() )
Set the heating interval (0-255). Default: 2 (20µs). Unit: 10µs.

According to section 5.2.9 of the datasheet: "The more heating interval, the more clear, but the slower printing speed."

# printer.setLineSpacing( spacing )
Set the space between each printed line vertically

Main methods

# printer.reset()
Resets printer

# printer.print( callback() )
Runs commands and prints. Run this last.

# printer.printLine( text )
Write text to printer

# printer.lineFeed( amountOfLines )
Feed blank lines out of the printer specified by argument

Printing modes

# printer.bold( onOff )
Makes text bolder

# printer.big( onOff )
Makes text bigger

# printer.underline( onOff )
Makes text underlined

# printer.small( onOff )
Makes text smaller

# printer.upsideDown( onOff )
Makes text upside down

# printer.inverse( onOff )
Makes text black on white

# printer.left( onOff )
Makes text aligned left

# printer.right( onOff )
Makes text aligned right

# onOff )
Makes text aligned center




# printer.barcodeTextPosition( positionValue )
Set text position relative to barcode. Positions are: 0: Not printed 1: Above the barcode 2: Below the barcode 3: Both above and below the barcode

# printer.barcode( Printer.BARCODE_TYPES.type, barcodeData )
Print barcode. The types you can use are: UPCA, UPCE, EAN13, EAN8, CODE39, I25, CODEBAR, CODE93, CODE128, CODE11, MSI


# printer.indent( amountOfColumns )
Create an indentation for text by an amount of cplumns

# printer.horizontalLine( length )
Draw a horizontal line at a certain length

check the example, will add the rest later


# printer.on( 'ready', callback() )
Emitted upon reset and printing settings on printer.

Further Examples

If you want to set options you can do so like this:

// ... 
var printer = thermalprinter.use(tessel.port['A'], {
    // baudrate for the printer default: 19200 
    baudrate: 19200,
    /* can be found by doing a print test. hold the button printer while
     * powering the printer on and it should spit out some shit at the
     * bottom is it should say the baudrate
    // Max printing dots (0-255), unit: (n+1)*8 dots, default: 7 ((7+1)*8 = 64 dots) 
    maxPrintingDots: 7,
    /* The more max heating dots, the more peak current will cost when printing,
     * the faster printing speed. The max heating dots is 8*(n+1).
    // Heating time (3-255), unit: 10µs, default: 80 (800µs) 
    heatingTime: 80,
    /* The more heating time, the more density, but the slower printing speed.
     * If heating time is too short, blank page may occur.
    // Heating interval (0-255), unit: 10µs, default: 2 (20µs) 
    heatingInterval: 2,
    /* The more heating interval, the more clear, but the slower printing speed.
// ... 

Hardware specifications and Advanced Information

  • Datasheet

  • Productsheet

  • Buy in US (Adafruit) / UK (Hobbytronics)

  • Requires 5-9VDC @ 1.5Amp power supply during print

  • Protocol: TTL Serial, 19200 baud

  • Mean Cycles Before Failure: 5 million lines

  • Printing Speed: 50-80mm/s

  • Resolution: 8 dots/mm, 384 dots/line


  • Requires 2.25" wide, 50 ft or shorter thermal paper
  • Effective Printing Width: 48mm
  • Outline Dimension (WxDxH): 111x65x57mm
  • Installation Port Size: 103 x 57mm

Character set

  • Character Set: ASCII,GB2312-80(Chinese)
  • Print Font: ANK:5×7, Chinese: 12x24,24×24


  • Paper Type: Thermal paper
  • Paper Width: 57.5 ±0.5mm
  • Paper Roll Diameter: max 39mm


  • Operating Temp: 5°C ~ 50°C
  • Operating Humidity: 10% ~ 80%
  • Storage Temp: -20°C ~ 60°C
  • Storage Humidity: 10% ~ 90%

Other libraries

Don't have a Tessel? As this uses serial it works with most things:


MIT or Apache 2.0