ESC/POS Thermal Printer and Mono (or .Net)
Recently, I found small thermal printers sold online, like the Sparkfun’s one. (You may find these en eBay too.) To communicate with these printers you will need a serial link, working at TTL levels.
So, I made ThermalDotNet: a .Net class to use these thermal printers.
First, the FTDI board to thermal printer wiring diagram (hand drawn, yay! \o/):
Printing (in C#) takes a few lines of code :
... using System.IO.Ports; using ThermalDotNet; //Don't forget to add the dll reference ... // Replace /dev/tty with the name of your serial port. // Can be COM1, COM2... on Windows, /dev/ttyUSB0 on Linux. SerialPort printerPort = new SerialPort("/dev/tty", 9600); // Connection to the printer ThermalPrinter printer = new ThermalPrinter(printerPort); printer.WakeUp(); // Let's wake up the printer printer.WriteLine("Hello World"); printer.LineFeed(); // Feed paper printer.Sleep(); // Save some energy Console.WriteLine("Printer is now offline."); printerPort.Close();
At the moment, theses features are supported :
- Simple text and standard text styles supported. (Bold, double size, reverse printing…)
- Barcodes support
- Image printing support (must be 384px wide)
- Printer configuration support (heating time, speed, etc.)
You must have a good power supply to make this printer work properly, mine is a cheap ’5V – 2A’ supply but its voltage falls down to 4.5V when the printing line needs a lot of black.
The workaround is to heat less dots at a time: by default 64 dots are heated up. I reduced this number to 16 in the printer configuration.
ThermalPrinter printer = new ThermalPrinter(serialPort); printer.SetPrintingParameters(2,220,1); or ThermalPrinter printer = new ThermalPrinter(serialPort,2,220,1); // (2+1*8) dots = 24 dots heated up at a time (instead of 64) // 220*10 µs = 2200 µs of heating time (instead of 800 µs) // 1*10 µs = 10 µs of heating interval (instead of 20 µs)
In compensation, the printer is slower. If you need a fast printing, get a good 9V – 2A power supply!
More to come…