xan/tabby
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

That comment better belongs in <tabby/avr.h> now

Browse source
This commit is contained in:
XANTRONIX Development 2016-06-05 20:40:56 -05:00
parent a2cb39f782
commit 3e2a43529a
2 changed files with 15 additions and 12 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

14
avr/send.c
View file

@ -12,20 +12,10 @@ static tabby_printer_response response;
static uint8_t body[TABBY_PRINTER_PACKET_MAX_SIZE]; static uint8_t body[TABBY_PRINTER_PACKET_MAX_SIZE];
static uint8_t sheet[TABBY_PRINTER_SHEET_SIZE];
static uint16_t sum; static uint16_t sum;
/*
* So like, we're abusing pins here. So badly, it's beyond. So here's
* what's going down: We want to retain the same physical I/O connections
* between both the sending and receiving flavors of the whole Game Boy
* Printer endeavor, and that mean/s that we must absolutely bit bang MOSI
* and MISO opposite from their ordinary roles. The reason being: There is
* no notion of MISO or MOSI from the Game Boy's (nor its peripherals')
* point of view. The SI and SO pins over a link cable are crossed over, so
* SI on one end always connects to SO on the other, and vice-versa. The SI
* and SO pins do not switch roles based on role, unlike on AVR SPI
* implementations.
*/
static void spi_init() { static void spi_init() {
SC_OUTPUT(); SC_OUTPUT();
SO_OUTPUT(); SO_OUTPUT();

13
include/tabby/avr.h
View file

@ -1,6 +1,19 @@
#ifndef _TABBY_AVR_H #ifndef _TABBY_AVR_H
#define _TABBY_AVR_H #define _TABBY_AVR_H
/*
* So like, we're abusing pins here. So badly, it's beyond. So here's
* what's going down: We want to retain the same physical I/O connections
* between both the sending and receiving flavors of the whole Game Boy
* Printer endeavor, and that mean/s that we must absolutely bit bang MOSI
* and MISO opposite from their ordinary roles. The reason being: There is
* no notion of MISO or MOSI from the Game Boy's (nor its peripherals')
* point of view. The SI and SO pins over a link cable are crossed over, so
* SI on one end always connects to SO on the other, and vice-versa. The SI
* and SO pins do not switch roles based on role, unlike on AVR SPI
* implementations.
*/
#define SPI_PULSE_USEC 61 #define SPI_PULSE_USEC 61
/* /*