Files
Momentum-Firmware/applications/plugins/protoview/protocols/b4b1.c
2023-01-23 14:21:10 -05:00

89 lines
3.0 KiB
C

/* PT/SC remotes. Usually 443.92 Mhz OOK.
*
* This line code is used in many remotes such as Princeton chips
* named PT2262, Silian Microelectronics SC5262 and others.
* Basically every 4 pulsee represent a bit, where 1000 means 0, and
* 1110 means 1. Usually we can read 24 bits of data.
* In this specific implementation we check for a prelude that is
* 1 bit high, 31 bits low, but the check is relaxed. */
#include "../app.h"
static bool decode(uint8_t *bits, uint32_t numbytes, uint32_t numbits, ProtoViewMsgInfo *info) {
if (numbits < 30) return false;
const char *sync_patterns[3] = {
"10000000000000000000000000000001", /* 30 zero bits. */
"100000000000000000000000000000001", /* 31 zero bits. */
"1000000000000000000000000000000001", /* 32 zero bits. */
};
uint32_t off;
int j;
for (j = 0; j < 3; j++) {
off = bitmap_seek_bits(bits,numbytes,0,numbits,sync_patterns[j]);
if (off != BITMAP_SEEK_NOT_FOUND) break;
}
if (off == BITMAP_SEEK_NOT_FOUND) return false;
if (DEBUG_MSG) FURI_LOG_E(TAG, "B4B1 preamble at: %lu",off);
info->start_off = off;
// Seek data setction. Why -1? Last bit is data.
off += strlen(sync_patterns[j])-1;
uint8_t d[3]; /* 24 bits of data. */
uint32_t decoded =
convert_from_line_code(d,sizeof(d),bits,numbytes,off,"1000","1110");
if (DEBUG_MSG) FURI_LOG_E(TAG, "B4B1 decoded: %lu",decoded);
if (decoded < 24) return false;
off += 24*4; // seek to end symbol offset to calculate the length.
off++; // In this protocol there is a final pulse as terminator.
info->pulses_count = off - info->start_off;
fieldset_add_bytes(info->fieldset,"id",d,5);
fieldset_add_uint(info->fieldset,"button",d[2]&0xf,4);
return true;
}
/* Give fields and defaults for the signal creator. */
static void get_fields(ProtoViewFieldSet *fieldset) {
uint8_t default_id[3]= {0xAB, 0xCD, 0xE0};
fieldset_add_bytes(fieldset,"id",default_id,5);
fieldset_add_uint(fieldset,"button",1,4);
}
/* Create a signal. */
static void build_message(RawSamplesBuffer *samples, ProtoViewFieldSet *fs)
{
uint32_t te = 334; // Short pulse duration in microseconds.
// Sync: 1 te pulse, 31 te gap.
raw_samples_add(samples,true,te);
raw_samples_add(samples,false,te*31);
// ID + button state
uint8_t data[3];
memcpy(data,fs->fields[0]->bytes,3);
data[2] = (data[2]&0xF0) | (fs->fields[1]->uvalue & 0xF);
for (uint32_t j = 0; j < 24; j++) {
if (bitmap_get(data,sizeof(data),j)) {
raw_samples_add(samples,true,te*3);
raw_samples_add(samples,false,te);
} else {
raw_samples_add(samples,true,te);
raw_samples_add(samples,false,te*3);
}
}
// Signal terminator. Just a single short pulse.
raw_samples_add(samples,true,te);
}
ProtoViewDecoder B4B1Decoder = {
.name = "PT/SC remote",
.decode = decode,
.get_fields = get_fields,
.build_message = build_message
};