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like yeah, whatever. a better state machine

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This commit is contained in:
XANTRONIX Development 2016-05-30 21:53:10 -05:00
parent ffa6882870
commit c34a79a9fd
4 changed files with 58 additions and 67 deletions
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2
avr/Makefile
View file

@ -12,7 +12,7 @@ OBJCOPY = $(CROSS)objcopy
OBJCOPY_FLAGS = -S
AVRDUDE = avrdude
AVRDUDE_DEVICE = /dev/cu.usbmodem1411
AVRDUDE_DEVICE = /dev/cu.usbmodem1421
AVRDUDE_FLAGS = -c arduino -p atmega328p -b 115200 -D -P $(AVRDUDE_DEVICE)
HEADERS_LOCAL =

12
bin/main.c
View file

@ -27,7 +27,8 @@ int main(int argc, char **argv) {
int fd, status;
tabby_printer_packet_header header;
tabby_printer_packet_footer footer;
uint16_t checksum;
uint8_t body[TABBY_PRINTER_MAX_PACKET_SIZE];
@ -43,7 +44,9 @@ int main(int argc, char **argv) {
}
while (1) {
status = tabby_printer_packet_recv(fd, &header, &body, &footer);
uint8_t value;
status = tabby_printer_packet_recv(fd, &header, &body, &checksum);
if (status < 0) {
fprintf(stderr, "%s: %s: %s\n",
@ -52,7 +55,10 @@ int main(int argc, char **argv) {
continue;
}
fprintf(stderr, "Got a packet\n");
value = 0x81;
tabby_link_send(fd, &value, 1);
value = 0x00;
tabby_link_send(fd, &value, 1);
}
tabby_link_close(fd);

15
include/tabby/printer.h
View file

@ -31,25 +31,12 @@ typedef struct _tabby_printer_packet_header {
};
} tabby_printer_packet_header;
typedef struct _tabby_printer_packet_footer {
union {
struct {
uint16_t checksum;
uint8_t peripheral,
status;
};
uint8_t data[4];
};
} tabby_printer_packet_footer;
/*
* Methods for communicating with Game Boy as a printer
*/
int tabby_printer_packet_recv(int fd, tabby_printer_packet_header *header,
void *body,
tabby_printer_packet_footer *footer);
uint16_t *checksum);
int tabby_printer_response_send(int fd, uint8_t device, uint8_t status);

94
src/printer.c
View file

@ -22,69 +22,67 @@ static uint16_t checksum(tabby_printer_packet_header *header, void *body) {
int tabby_printer_packet_recv(int fd, tabby_printer_packet_header *header,
void *body,
tabby_printer_packet_footer *footer) {
uint16_t *sum) {
ssize_t len;
size_t i = 0,
b = 0,
f = 0;
b = 0;
uint8_t value,
last;
int started = 0;
uint8_t value;
memset(header, '\0', sizeof(*header));
memset(footer, '\0', sizeof(*footer));
*sum = 0;
while ((len = tabby_link_recv(fd, &value, 1)) >= 0) {
if (started) {
if (i == 2) {
if (i == 0) {
if (value == 0x83) {
header->preamble[0] = value;
i++;
} else {
errno = EIO;
goto error_io;
}
} else if (i == 1) {
if (value == 0x33) {
header->preamble[1] = value;
i++;
} else {
errno = EIO;
i = 0;
goto error_io;
}
} else if (i == 2) {
header->type = value;
i++;
} else if (i == 3) {
header->compression = value;
} else if (i == 4 || i == 5) {
header->size <<= 8;
header->size |= value;
} else if (i > 5 && b < header->size) {
((uint8_t *)body)[b++] = value;
} else if (b >= header->size && f < 2) {
footer->checksum <<= 8;
footer->checksum |= value;
f++;
} else if (f >= 2) {
footer->data[f++] = value;
if (f == sizeof(*footer)) {
if (checksum(header, body) != footer->checksum) {
errno = EIO;
goto error_io;
}
return 0;
}
}
} else {
if (last == 0x88 && value == 0x33) {
started = 1;
i = 2;
b = 0;
f = 0;
} else if (i == PACKET_RECV_ERROR_THRESHOLD) {
errno = EIO;
goto error_io;
}
}
last = value;
i++;
} else if (i == 4) {
header->size = value;
i++;
} else if (i == 5) {
header->size |= value << 8;
i++;
b = 0;
} else if (b < header->size) {
((uint8_t *)body)[b++] = value;
} else if (b == header->size) {
*sum = value;
b++;
} else if (b == header->size + 1) {
*sum |= value << 8;
if (checksum(header, body) != *sum) {
errno = EIO;
goto error_io;
}
return errno = 0;
}
}
error_io:
return -errno;