4.6 KiB
ParallelPrinter
Arduino library that implements a parallel printer (driver) - implements the PRINT interface.
Description
This library defines a parallel printer object.
It implements the Print interface to be able to print all data types using write(), print() and println(). The printer writes every byte over 8 parallel lines including a STROBE (clock) pulse, while waiting for the connected printer not to be BUSY or OUT OF PAPER (OOP).
This library is meant to be a starting point to make a "printer driver" for a specific parallel printer. These can often be bought in 2nd hand stores or so.
Have fun!
Note: This lib is a extended redo of the ParPrinter class.
Interface
#include "ParallelPrinter.h"
Constructor
- ParallelPrinter() uses default pins (13, 2, 12, [3,4,5,6,7,8,9,10])
- ParallelPrinter(uint8_t strobe, uint8_t busy, uint8_t oop, uint8_t *arr) define 3 control pins + 8 data pins (= arr[8]).
- void begin(uint8_t lineLength, uint8_t pageLength) set line and page length parameters
Print interface
- size_t write(uint8_t c) send a single byte to printer, implements Print interface. Therefore all print() and println() functions will work.
- void formfeed() to eject current page or forced go to the next page.
- void linefeed() send a linefeed. The number of actual lines is set by setLineFeed()
Configuration
These settings are pretty straightforward.
- void setLineLength(uint8_t lineLength) idem
- uint8_t getLineLength() returns the current line length.
- void setPageLength(uint8_t pageLength) idem
- uint8_t getPageLength() returns the current page length.
- uint8_t getLineNumber() returns current line number.
- uint8_t getPageNumber() returns current page number.
- uint8_t getPosition() returns the position on a line.
- uint8_t setTabSize(uint8_t tabsize) tabs are replaced by spaces. n can be 0 or any size!
- uint8_t getTabSize() returns tabSize set
- void setLineFeed(uint8_t lineFeeds) lineFeeds = 1,2,3 1 = default.
- uint8_t getLineFeed() returns lineFeeds set
- void printLineNr(bool b) can be set to true, false.
Expert mode
- bool isOutOfPaper() to check paper tray before printing starts.
- void setStrobeDelay(uint16_t n = 2000) allows tuning of performance. Make the strobe pulse shorter == faster printing (printer dependant). Default value = 2000. Time in microseconds.
- uint16_t getStrobeDelay() returns value set.
Note mechanical printers e.g. dot matrix, really do need a way to stop receiving data as they do not have large buffers. (==> BUSY line)
See also
https://en.wikipedia.org/wiki/Parallel_port#Centronics
Operation
See examples.
Future
Must
- update documentation
Should
- extend unit tests?
- test more.
- extend simulator sketch.
- Make a front end of a parallel printer,
- Accepts the clocked bytes and print them e.g. over serial.
Could
- derive e.g. an HP or an EPSON printer from this class.
- special modes e.g. bold italic underline.
- write(uint8_t * buf, uint8_t length) should be added
- might not really add to performance..
- fix blocking TODO in sendByte
Wont
Support
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Thank you,