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[PCF7930] Refactoring & bugfix in READING
firs commit of a few to come. First renames of variables, added a few comments to improve clarity. Fixed types (int -> unitx_t , const, ...) - not all. still some to come Fixed 2 conditions that did not work properly. Here some explanation: Imagine dest[i-1] = 255 and dest[i] = 0. THis would mean a clear falling edge. However, this code would not work, since dest[i] > lmax is not true. This condition only works if I have at least 1 sample between lmax and 255. Same for the other way around.
This commit is contained in:
tinooo
Tino
parent
f8abfc0731
commit
3a8dc89dca
2 changed files with 115 additions and 48 deletions
154
armsrc/pcf7931.c
154
armsrc/pcf7931.c
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@ -37,84 +37,147 @@ size_t DemodPCF7931(uint8_t **outBlocks, bool ledcontrol) {
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uint8_t *dest = BigBuf_get_addr();
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int g_GraphTraceLen = BigBuf_max_traceLen();
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// limit g_GraphTraceLen to a little more than 2 data frames.
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// To make sure a complete dataframe is in the dataset.
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if (g_GraphTraceLen > 18000) {
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g_GraphTraceLen = 18000;
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}
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int i = 2, j, lastval, bitidx, half_switch;
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int clock = 64;
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int tolerance = clock / 8;
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int i = 2, j, bitPos;
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uint8_t half_switch;
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uint16_t bitPosLastEdge;
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uint16_t bitPosCurrentEdge;
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uint8_t lastClockDuration; // used to store the duration of the last "clock", for decoding.
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// clock may not be the correct term, maybe bit is better.
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// The duration between two edges is meant
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const uint8_t clock = 64;
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const uint8_t tolerance = clock / 8;
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const uint8_t _16T0 = clock/4;
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const uint8_t _32T0 = clock/2;
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const uint8_t _64T0 = clock;
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int pmc, block_done;
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int lc, warnings = 0;
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int warnings = 0;
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size_t num_blocks = 0;
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int lmin = 64, lmax = 192;
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uint8_t dir;
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// int lmin = 64, lmax = 192; // used for some thresholds to identify high/low
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uint8_t threshold = 30; // threshold to filter out noise, from an actual slope.
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EdgeType expectedNextEdge = UNDEFINED; // direction in which the next slope is expected should go.
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BigBuf_Clear_keep_EM();
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LFSetupFPGAForADC(LF_DIVISOR_125, true);
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DoAcquisition_default(0, true, ledcontrol);
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/* Find first local max/min */
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if (dest[1] > dest[0]) {
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while (i < g_GraphTraceLen) {
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if (!(dest[i] > dest[i - 1]) && dest[i] > lmax) {
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break;
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}
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i++;
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}
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dir = 0;
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} else {
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while (i < g_GraphTraceLen) {
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if (!(dest[i] < dest[i - 1]) && dest[i] < lmin) {
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break;
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}
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i++;
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}
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dir = 1;
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// /* Find first local max/min */
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// if (dest[1] > dest[0]) {
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// while (i < g_GraphTraceLen) {
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// // Todo: dont think that this condition is correct. same issue as below.
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// if (!(dest[i] > dest[i - 1]) && dest[i] > lmax) {
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// break;
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// }
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// i++;
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// }
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// dir = 0;
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// } else {
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// while (i < g_GraphTraceLen) {
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// // Todo: dont think that this condition is correct. same issue as below.
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// if (!(dest[i] < dest[i - 1]) && dest[i] < lmin) {
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// break;
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// }
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// i++;
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// }
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// dir = 1;
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// }
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i = 1;
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while (i < g_GraphTraceLen && expectedNextEdge==UNDEFINED) {
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// find falling edge
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if ((dest[i] + threshold) < dest[i-1]) {
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expectedNextEdge = RISING; // current edge is falling, so next has to be rising
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// find rising edge
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} else if ((dest[i] - threshold) > dest[i-1]){
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expectedNextEdge = FALLING; // current edge is rising, so next has to be falling
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}
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lastval = i++;
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i++;
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}
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bitPosLastEdge = i++;
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half_switch = 0;
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pmc = 0;
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block_done = 0;
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for (bitidx = 0; i < g_GraphTraceLen; i++) {
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for (bitPos = 0; i < g_GraphTraceLen; i++) {
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if ((dest[i - 1] > dest[i] && dir == 1 && dest[i] > lmax) || (dest[i - 1] < dest[i] && dir == 0 && dest[i] < lmin)) {
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lc = i - lastval;
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lastval = i;
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// Todo: This condition is not working properly. It is failing, in case the samples are falling/rising RAPIDLY.
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// Imagine dest[i-1] = 255 and dest[i] = 0. THis would mean a clear falling edge.
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// However, this code would not work, since dest[i] > lmax is not true.
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// This condition only works if I have at least 1 sample between lmax and 255.
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// Same for the other way around.
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// if ((dest[i - 1] > dest[i] && dir == 1 && dest[i] > lmax) || (dest[i - 1] < dest[i] && dir == 0 && dest[i] < lmin)) {
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// Switch depending on lc length:
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if (bitPos%4 == 0){
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//Dbprintf("dest[%d]: %d",i, dest[i]);
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}
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// condition is searching for the next slope, in the expected diretion.
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if ( ((dest[i] + threshold) < dest[i-1] && expectedNextEdge == FALLING ) ||
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((dest[i] - threshold) > dest[i-1] && expectedNextEdge == RISING )) {
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expectedNextEdge = (expectedNextEdge == FALLING) ? RISING : FALLING; //toggle the next expected edge
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//okay, next falling/rising edge found
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bitPosCurrentEdge = i;
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lastClockDuration = bitPosCurrentEdge - bitPosLastEdge;
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bitPosLastEdge = i;
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// Switch depending on lastClockDuration length:
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// Tolerance is 1/8 of clock rate (arbitrary)
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if (ABS(lc - clock / 4) < tolerance) {
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// 16T0
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if ((i - pmc) == lc) { // 16T0 was previous one
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if (ABS(lastClockDuration - _16T0) < tolerance) {
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if ((i - pmc) == lastClockDuration) { // 16T0 was previous one
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// It's a PMC
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Dbprintf(_GREEN_("PMC 16T0 FOUND:") " at i: %d", i);
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i += (128 + 127 + 16 + 32 + 33 + 16) - 1;
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lastval = i;
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bitPosLastEdge = i;
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pmc = 0;
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block_done = 1;
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} else {
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pmc = i;
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}
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} else if (ABS(lc - clock / 2) < tolerance) {
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// 32TO
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if ((i - pmc) == lc) { // 16T0 was previous one
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} else if (ABS(lastClockDuration - _32T0) < tolerance) {
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if ((i - pmc) == lastClockDuration) { // 16T0 was previous one
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// It's a PMC !
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Dbprintf(_GREEN_("PMC 32T0 FOUND:") " at i: %d", i);
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i += (128 + 127 + 16 + 32 + 33) - 1;
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lastval = i;
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bitPosLastEdge = i;
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pmc = 0;
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block_done = 1;
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// if no pmc, then its a normal bit. Check if its the second time, the edge changed
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// if yes, then the bit is 0
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} else if (half_switch == 1) {
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bits[bitidx++] = 0;
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bits[bitPos++] = 0;
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// reset the edge counter to 0
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half_switch = 0;
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// so it is the first time the edge changed. No bit value will be set here, bit if the
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// edge changes again, it will be. see case above.
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} else
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half_switch++;
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} else if (ABS(lc - clock) < tolerance) {
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// 64TO
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bits[bitidx++] = 1;
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} else {
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// 64T0
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} else if (ABS(lastClockDuration - _64T0) < tolerance) {
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bits[bitPos++] = 1;
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// Error
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} else {
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if (++warnings > 10) {
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if (g_dbglevel >= DBG_EXTENDED) {
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@ -126,7 +189,7 @@ size_t DemodPCF7931(uint8_t **outBlocks, bool ledcontrol) {
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}
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if (block_done == 1) {
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if (bitidx == 128) {
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if (bitPos == 128) {
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for (j = 0; j < 16; ++j) {
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blocks[num_blocks][j] =
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128 * bits[j * 8 + 7] +
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@ -141,18 +204,15 @@ size_t DemodPCF7931(uint8_t **outBlocks, bool ledcontrol) {
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}
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num_blocks++;
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}
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bitidx = 0;
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bitPos = 0;
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block_done = 0;
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half_switch = 0;
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}
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if (i < g_GraphTraceLen) {
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dir = (dest[i - 1] > dest[i]) ? 0 : 1;
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}
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}
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if (bitidx == 255) {
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bitidx = 0;
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if (bitPos == 255) {
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bitPos = 0;
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}
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if (num_blocks == 4) {
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@ -18,6 +18,13 @@
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#include "common.h"
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typedef enum{
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UNDEFINED,
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FALLING,
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RISING
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} EdgeType;
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size_t DemodPCF7931(uint8_t **outBlocks, bool ledcontrol);
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bool IsBlock0PCF7931(uint8_t *block);
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bool IsBlock1PCF7931(const uint8_t *block);
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