mirror of
https://github.com/DarkFlippers/unleashed-firmware
synced 2024-11-27 15:00:46 +00:00
692 lines
26 KiB
C
692 lines
26 KiB
C
/* Copyright (C) 2022-2023 Salvatore Sanfilippo -- All Rights Reserved
|
|
* See the LICENSE file for information about the license. */
|
|
|
|
#include "app.h"
|
|
|
|
bool decode_signal(RawSamplesBuffer* s, uint64_t len, ProtoViewMsgInfo* info);
|
|
|
|
/* =============================================================================
|
|
* Protocols table.
|
|
*
|
|
* Supported protocols go here, with the relevant implementation inside
|
|
* protocols/<name>.c
|
|
* ===========================================================================*/
|
|
|
|
extern ProtoViewDecoder Oregon2Decoder;
|
|
extern ProtoViewDecoder B4B1Decoder;
|
|
extern ProtoViewDecoder RenaultTPMSDecoder;
|
|
extern ProtoViewDecoder ToyotaTPMSDecoder;
|
|
extern ProtoViewDecoder SchraderTPMSDecoder;
|
|
extern ProtoViewDecoder SchraderEG53MA4TPMSDecoder;
|
|
extern ProtoViewDecoder CitroenTPMSDecoder;
|
|
extern ProtoViewDecoder FordTPMSDecoder;
|
|
extern ProtoViewDecoder KeeloqDecoder;
|
|
extern ProtoViewDecoder ProtoViewChatDecoder;
|
|
extern ProtoViewDecoder UnknownDecoder;
|
|
|
|
ProtoViewDecoder* Decoders[] = {
|
|
&Oregon2Decoder, /* Oregon sensors v2.1 protocol. */
|
|
&B4B1Decoder, /* PT, SC, ... 24 bits remotes. */
|
|
&RenaultTPMSDecoder, /* Renault TPMS. */
|
|
&ToyotaTPMSDecoder, /* Toyota TPMS. */
|
|
&SchraderTPMSDecoder, /* Schrader TPMS. */
|
|
&SchraderEG53MA4TPMSDecoder, /* Schrader EG53MA4 TPMS. */
|
|
&CitroenTPMSDecoder, /* Citroen TPMS. */
|
|
&FordTPMSDecoder, /* Ford TPMS. */
|
|
&KeeloqDecoder, /* Keeloq remote. */
|
|
&ProtoViewChatDecoder, /* Protoview simple text messages. */
|
|
|
|
/* Warning: the following decoder must stay at the end of the
|
|
* list. Otherwise would detect most signals and prevent the actaul
|
|
* decoders from handling them. */
|
|
&UnknownDecoder, /* General protocol detector. */
|
|
NULL};
|
|
|
|
/* =============================================================================
|
|
* Raw signal detection
|
|
* ===========================================================================*/
|
|
|
|
/* Return the time difference between a and b, always >= 0 since
|
|
* the absolute value is returned. */
|
|
uint32_t duration_delta(uint32_t a, uint32_t b) {
|
|
return a > b ? a - b : b - a;
|
|
}
|
|
|
|
/* Reset the current signal, so that a new one can be detected. */
|
|
void reset_current_signal(ProtoViewApp* app) {
|
|
app->signal_bestlen = 0;
|
|
app->signal_offset = 0;
|
|
app->signal_decoded = false;
|
|
raw_samples_reset(DetectedSamples);
|
|
raw_samples_reset(RawSamples);
|
|
free_msg_info(app->msg_info);
|
|
app->msg_info = NULL;
|
|
}
|
|
|
|
/* This function starts scanning samples at offset idx looking for the
|
|
* longest run of pulses, either high or low, that are not much different
|
|
* from each other, for a maximum of three duration classes.
|
|
* So for instance 50 successive pulses that are roughly long 340us or 670us
|
|
* will be sensed as a coherent signal (example: 312, 361, 700, 334, 667, ...)
|
|
*
|
|
* The classes are counted separtely for high and low signals (RF on / off)
|
|
* because many devices tend to have different pulse lenghts depending on
|
|
* the level of the pulse.
|
|
*
|
|
* For instance Oregon2 sensors, in the case of protocol 2.1 will send
|
|
* pulses of ~400us (RF on) VS ~580us (RF off). */
|
|
#define SEARCH_CLASSES 3
|
|
uint32_t search_coherent_signal(RawSamplesBuffer* s, uint32_t idx, uint32_t min_duration) {
|
|
struct {
|
|
uint32_t dur[2]; /* dur[0] = low, dur[1] = high */
|
|
uint32_t count[2]; /* Associated observed frequency. */
|
|
} classes[SEARCH_CLASSES];
|
|
|
|
memset(classes, 0, sizeof(classes));
|
|
|
|
// Set a min/max duration limit for samples to be considered part of a
|
|
// coherent signal. The maximum length is fixed while the minimum
|
|
// is passed as argument, as depends on the data rate and in general
|
|
// on the signal to analyze.
|
|
uint32_t max_duration = 4000;
|
|
|
|
uint32_t len = 0; /* Observed len of coherent samples. */
|
|
s->short_pulse_dur = 0;
|
|
for(uint32_t j = idx; j < idx + s->total; j++) {
|
|
bool level;
|
|
uint32_t dur;
|
|
raw_samples_get(s, j, &level, &dur);
|
|
|
|
if(dur < min_duration || dur > max_duration) break; /* return. */
|
|
|
|
/* Let's see if it matches a class we already have or if we
|
|
* can populate a new (yet empty) class. */
|
|
uint32_t k;
|
|
for(k = 0; k < SEARCH_CLASSES; k++) {
|
|
if(classes[k].count[level] == 0) {
|
|
classes[k].dur[level] = dur;
|
|
classes[k].count[level] = 1;
|
|
break; /* Sample accepted. */
|
|
} else {
|
|
uint32_t classavg = classes[k].dur[level];
|
|
uint32_t count = classes[k].count[level];
|
|
uint32_t delta = duration_delta(dur, classavg);
|
|
/* Is the difference in duration between this signal and
|
|
* the class we are inspecting less than a given percentage?
|
|
* If so, accept this signal. */
|
|
if(delta < classavg / 5) { /* 100%/5 = 20%. */
|
|
/* It is useful to compute the average of the class
|
|
* we are observing. We know how many samples we got so
|
|
* far, so we can recompute the average easily.
|
|
* By always having a better estimate of the pulse len
|
|
* we can avoid missing next samples in case the first
|
|
* observed samples are too off. */
|
|
classavg = ((classavg * count) + dur) / (count + 1);
|
|
classes[k].dur[level] = classavg;
|
|
classes[k].count[level]++;
|
|
break; /* Sample accepted. */
|
|
}
|
|
}
|
|
}
|
|
|
|
if(k == SEARCH_CLASSES) break; /* No match, return. */
|
|
|
|
/* If we are here, we accepted this sample. Try with the next
|
|
* one. */
|
|
len++;
|
|
}
|
|
|
|
/* Update the buffer setting the shortest pulse we found
|
|
* among the three classes. This will be used when scaling
|
|
* for visualization. */
|
|
uint32_t short_dur[2] = {0, 0};
|
|
for(int j = 0; j < SEARCH_CLASSES; j++) {
|
|
for(int level = 0; level < 2; level++) {
|
|
if(classes[j].dur[level] == 0) continue;
|
|
if(classes[j].count[level] < 3) continue;
|
|
if(short_dur[level] == 0 || short_dur[level] > classes[j].dur[level]) {
|
|
short_dur[level] = classes[j].dur[level];
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Use the average between high and low short pulses duration.
|
|
* Often they are a bit different, and using the average is more robust
|
|
* when we do decoding sampling at short_pulse_dur intervals. */
|
|
if(short_dur[0] == 0) short_dur[0] = short_dur[1];
|
|
if(short_dur[1] == 0) short_dur[1] = short_dur[0];
|
|
s->short_pulse_dur = (short_dur[0] + short_dur[1]) / 2;
|
|
|
|
return len;
|
|
}
|
|
|
|
/* Called when we detect a message. Just blinks when the message was
|
|
* not decoded. Vibrates, too, when the message was correctly decoded. */
|
|
void notify_signal_detected(ProtoViewApp* app, bool decoded) {
|
|
static const NotificationSequence decoded_seq = {
|
|
&message_vibro_on,
|
|
&message_green_255,
|
|
&message_delay_50,
|
|
&message_green_0,
|
|
&message_vibro_off,
|
|
NULL};
|
|
|
|
static const NotificationSequence unknown_seq = {
|
|
&message_red_255, &message_delay_50, &message_red_0, NULL};
|
|
|
|
if(decoded)
|
|
notification_message(app->notification, &decoded_seq);
|
|
else
|
|
notification_message(app->notification, &unknown_seq);
|
|
}
|
|
|
|
/* Search the source buffer with the stored signal (last N samples received)
|
|
* in order to find a coherent signal. If a signal that does not appear to
|
|
* be just noise is found, it is set in DetectedSamples global signal
|
|
* buffer, that is what is rendered on the screen. */
|
|
void scan_for_signal(ProtoViewApp* app, RawSamplesBuffer* source, uint32_t min_duration) {
|
|
/* We need to work on a copy: the source buffer may be populated
|
|
* by the background thread receiving data. */
|
|
RawSamplesBuffer* copy = raw_samples_alloc();
|
|
raw_samples_copy(copy, source);
|
|
|
|
/* Try to seek on data that looks to have a regular high low high low
|
|
* pattern. */
|
|
uint32_t minlen = 18; /* Min run of coherent samples. With less
|
|
than a few samples it's very easy to
|
|
mistake noise for signal. */
|
|
|
|
uint32_t i = 0;
|
|
|
|
while(i < copy->total - 1) {
|
|
uint32_t thislen = search_coherent_signal(copy, i, min_duration);
|
|
|
|
/* For messages that are long enough, attempt decoding. */
|
|
if(thislen > minlen) {
|
|
/* Allocate the message information that some decoder may
|
|
* fill, in case it is able to decode a message. */
|
|
ProtoViewMsgInfo* info = malloc(sizeof(ProtoViewMsgInfo));
|
|
init_msg_info(info, app);
|
|
info->short_pulse_dur = copy->short_pulse_dur;
|
|
|
|
uint32_t saved_idx = copy->idx; /* Save index, see later. */
|
|
|
|
/* decode_signal() expects the detected signal to start
|
|
* from index zero .*/
|
|
raw_samples_center(copy, i);
|
|
bool decoded = decode_signal(copy, thislen, info);
|
|
copy->idx = saved_idx; /* Restore the index as we are scanning
|
|
the signal in the loop. */
|
|
|
|
/* Accept this signal as the new signal if either it's longer
|
|
* than the previous undecoded one, or the previous one was
|
|
* unknown and this is decoded. */
|
|
bool oldsignal_not_decoded = app->signal_decoded == false ||
|
|
app->msg_info->decoder == &UnknownDecoder;
|
|
|
|
if(oldsignal_not_decoded &&
|
|
(thislen > app->signal_bestlen || (decoded && info->decoder != &UnknownDecoder))) {
|
|
free_msg_info(app->msg_info);
|
|
app->msg_info = info;
|
|
app->signal_bestlen = thislen;
|
|
app->signal_decoded = decoded;
|
|
raw_samples_copy(DetectedSamples, copy);
|
|
raw_samples_center(DetectedSamples, i);
|
|
FURI_LOG_E(
|
|
TAG,
|
|
"===> Displayed sample updated (%d samples %lu us)",
|
|
(int)thislen,
|
|
DetectedSamples->short_pulse_dur);
|
|
|
|
adjust_raw_view_scale(app, DetectedSamples->short_pulse_dur);
|
|
if(app->msg_info->decoder != &UnknownDecoder) notify_signal_detected(app, decoded);
|
|
} else {
|
|
/* If the structure was not filled, discard it. Otherwise
|
|
* now the owner is app->msg_info. */
|
|
free_msg_info(info);
|
|
}
|
|
}
|
|
i += thislen ? thislen : 1;
|
|
}
|
|
raw_samples_free(copy);
|
|
}
|
|
|
|
/* =============================================================================
|
|
* Decoding
|
|
*
|
|
* The following code will translates the raw singals as received by
|
|
* the CC1101 into logical signals: a bitmap of 0s and 1s sampled at
|
|
* the detected data clock interval.
|
|
*
|
|
* Then the converted signal is passed to the protocols decoders, that look
|
|
* for protocol-specific information. We stop at the first decoder that is
|
|
* able to decode the data, so protocols here should be registered in
|
|
* order of complexity and specificity, with the generic ones at the end.
|
|
* ===========================================================================*/
|
|
|
|
/* Set the 'bitpos' bit to value 'val', in the specified bitmap
|
|
* 'b' of len 'blen'.
|
|
* Out of range bits will silently be discarded. */
|
|
void bitmap_set(uint8_t* b, uint32_t blen, uint32_t bitpos, bool val) {
|
|
uint32_t byte = bitpos / 8;
|
|
uint32_t bit = 7 - (bitpos & 7);
|
|
if(byte >= blen) return;
|
|
if(val)
|
|
b[byte] |= 1 << bit;
|
|
else
|
|
b[byte] &= ~(1 << bit);
|
|
}
|
|
|
|
/* Get the bit 'bitpos' of the bitmap 'b' of 'blen' bytes.
|
|
* Out of range bits return false (not bit set). */
|
|
bool bitmap_get(uint8_t* b, uint32_t blen, uint32_t bitpos) {
|
|
uint32_t byte = bitpos / 8;
|
|
uint32_t bit = 7 - (bitpos & 7);
|
|
if(byte >= blen) return 0;
|
|
return (b[byte] & (1 << bit)) != 0;
|
|
}
|
|
|
|
/* Copy 'count' bits from the bitmap 's' of 'slen' total bytes, to the
|
|
* bitmap 'd' of 'dlen' total bytes. The bits are copied starting from
|
|
* offset 'soff' of the source bitmap to the offset 'doff' of the
|
|
* destination bitmap. */
|
|
void bitmap_copy(
|
|
uint8_t* d,
|
|
uint32_t dlen,
|
|
uint32_t doff,
|
|
uint8_t* s,
|
|
uint32_t slen,
|
|
uint32_t soff,
|
|
uint32_t count) {
|
|
/* If we are byte-aligned in both source and destination, use a fast
|
|
* path for the number of bytes we can consume this way. */
|
|
if((doff & 7) == 0 && (soff & 7) == 0) {
|
|
uint32_t didx = doff / 8;
|
|
uint32_t sidx = soff / 8;
|
|
while(count > 8 && didx < dlen && sidx < slen) {
|
|
d[didx++] = s[sidx++];
|
|
count -= 8;
|
|
}
|
|
doff = didx * 8;
|
|
soff = sidx * 8;
|
|
/* Note that if we entered this path, the count at the end
|
|
* of the loop will be < 8. */
|
|
}
|
|
|
|
/* Copy the bits needed to reach an offset where we can copy
|
|
* two half bytes of src to a full byte of destination. */
|
|
while(count > 8 && (doff & 7) != 0) {
|
|
bool bit = bitmap_get(s, slen, soff++);
|
|
bitmap_set(d, dlen, doff++, bit);
|
|
count--;
|
|
}
|
|
|
|
/* If we are here and count > 8, we have an offset that is byte aligned
|
|
* to the destination bitmap, but not aligned to the source bitmap.
|
|
* We can copy fast enough by shifting each two bytes of the original
|
|
* bitmap.
|
|
*
|
|
* This is how it works:
|
|
*
|
|
* dst:
|
|
* +--------+--------+--------+
|
|
* | 0 | 1 | 2 |
|
|
* | | | | <- data to fill
|
|
* +--------+--------+--------+
|
|
* ^
|
|
* |
|
|
* doff = 8
|
|
*
|
|
* src:
|
|
* +--------+--------+--------+
|
|
* | 0 | 1 | 2 |
|
|
* |hellowor|ld!HELLO|WORLDS!!| <- data to copy
|
|
* +--------+--------+--------+
|
|
* ^
|
|
* |
|
|
* soff = 11
|
|
*
|
|
* skew = 11%8 = 3
|
|
* each destination byte in dst will receive:
|
|
*
|
|
* dst[doff/8] = (src[soff/8] << skew) | (src[soff/8+1] >> (8-skew))
|
|
*
|
|
* dstbyte = doff/8 = 8/8 = 1
|
|
* srcbyte = soff/8 = 11/8 = 1
|
|
*
|
|
* so dst[1] will get:
|
|
* src[1] << 3, that is "ld!HELLO" << 3 = "HELLO..."
|
|
* xored with
|
|
* src[2] << 5, that is "WORLDS!!" >> 5 = ".....WOR"
|
|
* That is "HELLOWOR"
|
|
*/
|
|
if(count > 8) {
|
|
uint8_t skew = soff % 8; /* Don't worry, compiler will optimize. */
|
|
uint32_t didx = doff / 8;
|
|
uint32_t sidx = soff / 8;
|
|
while(count > 8 && didx < dlen && sidx < slen) {
|
|
d[didx] = ((s[sidx] << skew) | (s[sidx + 1] >> (8 - skew)));
|
|
sidx++;
|
|
didx++;
|
|
soff += 8;
|
|
doff += 8;
|
|
count -= 8;
|
|
}
|
|
}
|
|
|
|
/* Here count is guaranteed to be < 8.
|
|
* Copy the final bits bit by bit. */
|
|
while(count) {
|
|
bool bit = bitmap_get(s, slen, soff++);
|
|
bitmap_set(d, dlen, doff++, bit);
|
|
count--;
|
|
}
|
|
}
|
|
|
|
/* We decode bits assuming the first bit we receive is the MSB
|
|
* (see bitmap_set/get functions). Certain devices send data
|
|
* encoded in the reverse way. */
|
|
void bitmap_reverse_bytes_bits(uint8_t* p, uint32_t len) {
|
|
for(uint32_t j = 0; j < len; j++) {
|
|
uint32_t b = p[j];
|
|
/* Step 1: swap the two nibbles: 12345678 -> 56781234 */
|
|
b = (b & 0xf0) >> 4 | (b & 0x0f) << 4;
|
|
/* Step 2: swap adjacent pairs : 56781234 -> 78563412 */
|
|
b = (b & 0xcc) >> 2 | (b & 0x33) << 2;
|
|
/* Step 3: swap adjacent bits : 78563412 -> 87654321 */
|
|
b = (b & 0xaa) >> 1 | (b & 0x55) << 1;
|
|
p[j] = b;
|
|
}
|
|
}
|
|
|
|
/* Return true if the specified sequence of bits, provided as a string in the
|
|
* form "11010110..." is found in the 'b' bitmap of 'blen' bits at 'bitpos'
|
|
* position. */
|
|
bool bitmap_match_bits(uint8_t* b, uint32_t blen, uint32_t bitpos, const char* bits) {
|
|
for(size_t j = 0; bits[j]; j++) {
|
|
bool expected = (bits[j] == '1') ? true : false;
|
|
if(bitmap_get(b, blen, bitpos + j) != expected) return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/* Search for the specified bit sequence (see bitmap_match_bits() for details)
|
|
* in the bitmap 'b' of 'blen' bytes, looking forward at most 'maxbits' ahead.
|
|
* Returns the offset (in bits) of the match, or BITMAP_SEEK_NOT_FOUND if not
|
|
* found.
|
|
*
|
|
* Note: there are better algorithms, such as Boyer-Moore. Here we hope that
|
|
* for the kind of patterns we search we'll have a lot of early stops so
|
|
* we use a vanilla approach. */
|
|
uint32_t bitmap_seek_bits(
|
|
uint8_t* b,
|
|
uint32_t blen,
|
|
uint32_t startpos,
|
|
uint32_t maxbits,
|
|
const char* bits) {
|
|
uint32_t endpos = startpos + blen * 8;
|
|
uint32_t end2 = startpos + maxbits;
|
|
if(end2 < endpos) endpos = end2;
|
|
for(uint32_t j = startpos; j < endpos; j++)
|
|
if(bitmap_match_bits(b, blen, j, bits)) return j;
|
|
return BITMAP_SEEK_NOT_FOUND;
|
|
}
|
|
|
|
/* Compare bitmaps b1 and b2 (possibly overlapping or the same bitmap),
|
|
* at the specified offsets, for cmplen bits. Returns true if the
|
|
* exact same bits are found, otherwise false. */
|
|
bool bitmap_match_bitmap(
|
|
uint8_t* b1,
|
|
uint32_t b1len,
|
|
uint32_t b1off,
|
|
uint8_t* b2,
|
|
uint32_t b2len,
|
|
uint32_t b2off,
|
|
uint32_t cmplen) {
|
|
for(uint32_t j = 0; j < cmplen; j++) {
|
|
bool bit1 = bitmap_get(b1, b1len, b1off + j);
|
|
bool bit2 = bitmap_get(b2, b2len, b2off + j);
|
|
if(bit1 != bit2) return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/* Convert 'len' bitmap bits of the bitmap 'bitmap' into a null terminated
|
|
* string, stored at 'dst', that must have space at least for len+1 bytes.
|
|
* The bits are extracted from the specified offset. */
|
|
void bitmap_to_string(char* dst, uint8_t* b, uint32_t blen, uint32_t off, uint32_t len) {
|
|
for(uint32_t j = 0; j < len; j++) dst[j] = bitmap_get(b, blen, off + j) ? '1' : '0';
|
|
dst[len] = 0;
|
|
}
|
|
|
|
/* Set the pattern 'pat' into the bitmap 'b' of max length 'blen' bytes,
|
|
* starting from the specified offset.
|
|
*
|
|
* The pattern is given as a string of 0s and 1s characters, like "01101001".
|
|
* This function is useful in order to set the test vectors in the protocol
|
|
* decoders, to see if the decoding works regardless of the fact we are able
|
|
* to actually receive a given signal. */
|
|
void bitmap_set_pattern(uint8_t* b, uint32_t blen, uint32_t off, const char* pat) {
|
|
uint32_t i = 0;
|
|
while(pat[i]) {
|
|
bitmap_set(b, blen, i + off, pat[i] == '1');
|
|
i++;
|
|
}
|
|
}
|
|
|
|
/* Take the raw signal and turn it into a sequence of bits inside the
|
|
* buffer 'b'. Note that such 0s and 1s are NOT the actual data in the
|
|
* signal, but is just a low level representation of the line code. Basically
|
|
* if the short pulse we find in the signal is 320us, we convert high and
|
|
* low levels in the raw sample in this way:
|
|
*
|
|
* If for instance we see a high level lasting ~600 us, we will add
|
|
* two 1s bit. If then the signal goes down for 330us, we will add one zero,
|
|
* and so forth. So for each period of high and low we find the closest
|
|
* multiple and set the relevant number of bits.
|
|
*
|
|
* In case of a short pulse of 320us detected, 320*2 is the closest to a
|
|
* high pulse of 600us, so 2 bits will be set.
|
|
*
|
|
* In other terms what this function does is sampling the signal at
|
|
* fixed 'rate' intervals.
|
|
*
|
|
* This representation makes it simple to decode the signal at a higher
|
|
* level later, translating it from Marshal coding or other line codes
|
|
* to the actual bits/bytes.
|
|
*
|
|
* The 'idx' argument marks the detected signal start index into the
|
|
* raw samples buffer. The 'count' tells the function how many raw
|
|
* samples to convert into bits. The function returns the number of
|
|
* bits set into the buffer 'b'. The 'rate' argument, in microseconds, is
|
|
* the detected short-pulse duration. We expect the line code to be
|
|
* meaningful when interpreted at multiples of 'rate'. */
|
|
uint32_t convert_signal_to_bits(
|
|
uint8_t* b,
|
|
uint32_t blen,
|
|
RawSamplesBuffer* s,
|
|
uint32_t idx,
|
|
uint32_t count,
|
|
uint32_t rate) {
|
|
if(rate == 0) return 0; /* We can't perform the conversion. */
|
|
uint32_t bitpos = 0;
|
|
for(uint32_t j = 0; j < count; j++) {
|
|
uint32_t dur;
|
|
bool level;
|
|
raw_samples_get(s, j + idx, &level, &dur);
|
|
|
|
uint32_t numbits = dur / rate; /* full bits that surely fit. */
|
|
uint32_t rest = dur % rate; /* How much we are left with. */
|
|
if(rest > rate / 2) numbits++; /* There is another one. */
|
|
|
|
/* Limit how much a single sample can spawn. There are likely no
|
|
* protocols doing such long pulses when the rate is low. */
|
|
if(numbits > 1024) numbits = 1024;
|
|
|
|
if(0) /* Super verbose, so not under the DEBUG_MSG define. */
|
|
FURI_LOG_E(TAG, "%lu converted into %lu (%d) bits", dur, numbits, (int)level);
|
|
|
|
/* If the signal is too short, let's claim it an interference
|
|
* and ignore it completely. */
|
|
if(numbits == 0) continue;
|
|
|
|
while(numbits--) bitmap_set(b, blen, bitpos++, level);
|
|
}
|
|
return bitpos;
|
|
}
|
|
|
|
/* This function converts the line code used to the final data representation.
|
|
* The representation is put inside 'buf', for up to 'buflen' bytes of total
|
|
* data. For instance in order to convert manchester you can use "10" and "01"
|
|
* as zero and one patterns. However this function does not handle differential
|
|
* encodings. See below for convert_from_diff_manchester().
|
|
*
|
|
* The function returns the number of bits converted. It will stop as soon
|
|
* as it finds a pattern that does not match zero or one patterns, or when
|
|
* the end of the bitmap pointed by 'bits' is reached (the length is
|
|
* specified in bytes by the caller, via the 'len' parameters).
|
|
*
|
|
* The decoding starts at the specified offset (in bits) 'off'. */
|
|
uint32_t convert_from_line_code(
|
|
uint8_t* buf,
|
|
uint64_t buflen,
|
|
uint8_t* bits,
|
|
uint32_t len,
|
|
uint32_t off,
|
|
const char* zero_pattern,
|
|
const char* one_pattern) {
|
|
uint32_t decoded = 0; /* Number of bits extracted. */
|
|
len *= 8; /* Convert bytes to bits. */
|
|
while(off < len) {
|
|
bool bitval;
|
|
if(bitmap_match_bits(bits, len, off, zero_pattern)) {
|
|
bitval = false;
|
|
off += strlen(zero_pattern);
|
|
} else if(bitmap_match_bits(bits, len, off, one_pattern)) {
|
|
bitval = true;
|
|
off += strlen(one_pattern);
|
|
} else {
|
|
break;
|
|
}
|
|
bitmap_set(buf, buflen, decoded++, bitval);
|
|
if(decoded / 8 == buflen) break; /* No space left on target buffer. */
|
|
}
|
|
return decoded;
|
|
}
|
|
|
|
/* Convert the differential Manchester code to bits. This is similar to
|
|
* convert_from_line_code() but specific for diff-Manchester. The user must
|
|
* supply the value of the previous symbol before this stream, since
|
|
* in differential codings the next bits depend on the previous one.
|
|
*
|
|
* Parameters and return values are like convert_from_line_code(). */
|
|
uint32_t convert_from_diff_manchester(
|
|
uint8_t* buf,
|
|
uint64_t buflen,
|
|
uint8_t* bits,
|
|
uint32_t len,
|
|
uint32_t off,
|
|
bool previous) {
|
|
uint32_t decoded = 0;
|
|
len *= 8; /* Conver to bits. */
|
|
for(uint32_t j = off; j < len; j += 2) {
|
|
bool b0 = bitmap_get(bits, len, j);
|
|
bool b1 = bitmap_get(bits, len, j + 1);
|
|
if(b0 == previous) break; /* Each new bit must switch value. */
|
|
bitmap_set(buf, buflen, decoded++, b0 == b1);
|
|
previous = b1;
|
|
if(decoded / 8 == buflen) break; /* No space left on target buffer. */
|
|
}
|
|
return decoded;
|
|
}
|
|
|
|
/* Free the message info and allocated data. */
|
|
void free_msg_info(ProtoViewMsgInfo* i) {
|
|
if(i == NULL) return;
|
|
fieldset_free(i->fieldset);
|
|
free(i->bits);
|
|
free(i);
|
|
}
|
|
|
|
/* Reset the message info structure before passing it to the decoding
|
|
* functions. */
|
|
void init_msg_info(ProtoViewMsgInfo* i, ProtoViewApp* app) {
|
|
UNUSED(app);
|
|
memset(i, 0, sizeof(ProtoViewMsgInfo));
|
|
i->bits = NULL;
|
|
i->fieldset = fieldset_new();
|
|
}
|
|
|
|
/* This function is called when a new signal is detected. It converts it
|
|
* to a bitstream, and the calls the protocol specific functions for
|
|
* decoding. If the signal was decoded correctly by some protocol, true
|
|
* is returned. Otherwise false is returned. */
|
|
bool decode_signal(RawSamplesBuffer* s, uint64_t len, ProtoViewMsgInfo* info) {
|
|
uint32_t bitmap_bits_size = 4096 * 8;
|
|
uint32_t bitmap_size = bitmap_bits_size / 8;
|
|
|
|
/* We call the decoders with an offset a few samples before the actual
|
|
* signal detected and for a len of a few bits after its end. */
|
|
uint32_t before_samples = 32;
|
|
uint32_t after_samples = 100;
|
|
|
|
uint8_t* bitmap = malloc(bitmap_size);
|
|
uint32_t bits = convert_signal_to_bits(
|
|
bitmap,
|
|
bitmap_size,
|
|
s,
|
|
-before_samples,
|
|
len + before_samples + after_samples,
|
|
s->short_pulse_dur);
|
|
|
|
if(DEBUG_MSG) { /* Useful for debugging purposes. Don't remove. */
|
|
char* str = malloc(1024);
|
|
uint32_t j;
|
|
for(j = 0; j < bits && j < 1023; j++) {
|
|
str[j] = bitmap_get(bitmap, bitmap_size, j) ? '1' : '0';
|
|
}
|
|
str[j] = 0;
|
|
FURI_LOG_E(TAG, "%lu bits sampled: %s", bits, str);
|
|
free(str);
|
|
}
|
|
|
|
/* Try all the decoders available. */
|
|
int j = 0;
|
|
|
|
bool decoded = false;
|
|
while(Decoders[j]) {
|
|
uint32_t start_time = furi_get_tick();
|
|
decoded = Decoders[j]->decode(bitmap, bitmap_size, bits, info);
|
|
uint32_t delta = furi_get_tick() - start_time;
|
|
FURI_LOG_E(TAG, "Decoder %s took %lu ms", Decoders[j]->name, (unsigned long)delta);
|
|
if(decoded) {
|
|
info->decoder = Decoders[j];
|
|
break;
|
|
}
|
|
j++;
|
|
}
|
|
|
|
if(!decoded) {
|
|
FURI_LOG_E(TAG, "No decoding possible");
|
|
} else {
|
|
FURI_LOG_E(TAG, "+++ Decoded %s", info->decoder->name);
|
|
/* The message was correctly decoded: fill the info structure
|
|
* with the decoded signal. The decoder may not implement offset/len
|
|
* filling of the structure. In such case we have no info and
|
|
* pulses_count will be set to zero. */
|
|
if(info->pulses_count) {
|
|
info->bits_bytes = (info->pulses_count + 7) / 8; // Round to full byte.
|
|
info->bits = malloc(info->bits_bytes);
|
|
bitmap_copy(
|
|
info->bits,
|
|
info->bits_bytes,
|
|
0,
|
|
bitmap,
|
|
bitmap_size,
|
|
info->start_off,
|
|
info->pulses_count);
|
|
}
|
|
}
|
|
free(bitmap);
|
|
return decoded;
|
|
}
|