Printer

IR printer functions. More...

Macros
#define	PRINT_GRA_LN   1
	Graphics line type for printer buffer emulation.
#define	PRINT_TXT_LN   0
	Text line type for printer buffer emulation.
#define	MAX_82240_WIDTH   166
	Printer line width (pixels)
#define	DFLT_82240_LINE_DUR   1800
	Default line print delay.

Functions
void	print_byte (uint8_t b)
	Send byte to printer.
void	print_buffer (uint8_t *buf, int cnt)
	Send bytes to printer.
int	print_is_ready ()
	Check whether IR hw is ready for send.
uint	printer_get_delay ()
	Returns current printer line delay.
void	printer_set_delay (uint val)
	Sets printer line delay.
void	printer_advance_buf (int what)
	Add line type to printer buffer emulation.
int	printer_busy_for (int what)
	Wait until printer buffer is free for given line type.

Detailed Description

IR printer functions.

At this time supports HP-82240 compatible printers only.

Printer Buffer Management

The "printer buffer" here denotes the buffer inside HP-82240 printer.

DMCP supports delay timers, but application has to handle delays according to the printer usage.

Note that IR printer is unidirectional device and all buffer timing is based on estimates. Use printer_set_delay to fine-tune line delay.

Function printer_busy_for (ln_type), where ln_type is
PRINT_GRA_LN - waits until whole printer buffer is empty
PRINT_TXT_LN - waits until plain text line (25 characters) fits into printer buffer

Function printer_advance_buf (ln_type) updates printer buffer timers

Code example for blocking approach (pr_buf contains single line with pr_len bytes of data to print)

// prlen > 25 is just an example
int ln_type = (pr_len > 25) ? PRINT_GRA_LN : PRINT_TXT_LN;
 
// Wait until sufficient printer buffer space is ready
while ( printer_busy_for(ln_type) ) {
  // Do something useful
}
 
for(x=0; x<pr_len; x++)
  print_byte( pr_send_buf[x] );
 
// Update buffer timers with appropriate line type
printer_advance_buf(ln_type);

Function Documentation

print_buffer()

void print_buffer	(	uint8_t *	buf,
		int	cnt )

Send bytes to printer.

Bytes are sent directly to IR port.

Parameters

buf	Bytes to send
cnt	Number of bytes to send

print_byte()

void print_byte

(

uint8_t

b

)

Send byte to printer.

Byte is sent directly to IR port.

Parameters

b	Byte to send

print_is_ready()

int print_is_ready

(

)

Check whether IR hw is ready for send.

Returns

(0/1) 1 = IR hw is ready

printer_advance_buf()

void printer_advance_buf

(

int

what

)

Add line type to printer buffer emulation.

See Printer Buffer Management for more details.

Parameters

what	Printer line type

printer_busy_for()

int printer_busy_for

(

int

what

)

Wait until printer buffer is free for given line type.

See Printer Buffer Management for more details.

Parameters

what	Printer line type

printer_get_delay()

uint printer_get_delay

(

)

Returns current printer line delay.

Returns

[ms] Printer line delay

printer_set_delay()

void printer_set_delay

(

uint

val

)

Sets printer line delay.

Parameters

val	[ms] Printer line delay