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Sniff15693: Implementation of Autocalibration command
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Signed-off-by: cacke-r <cresch@gmx.de>
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@cacke-r
cacke-r committed Feb 23, 2022
1 parent 821de78 commit ad16434
Showing 1 changed file with 177 additions and 3 deletions.
180 changes: 177 additions & 3 deletions Firmware/Chameleon-Mini/Application/Sniff15693.c
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Original file line number Diff line number Diff line change
Expand Up @@ -10,7 +10,58 @@
#include "../Codec/SniffISO15693.h"
#include "Sniff15693.h"

/* Incrementing in steps of 50 was considered as sufficiently */
/* accurate during tests */
#define ISO15693_TH_CALIBRATE_STEPS 50
//#define ISO15693_DEBUG_LOG
typedef enum {
AUTOCALIB_INIT,
AUTOCALIB_READER_DATA,
AUTOCALIB_CARD_DATA,
} Sniff15693State;

Sniff15693Command Sniff15693CurrentCommand;
static Sniff15693State autocalib_state = AUTOCALIB_INIT;

/* The Autocalib shall work as following: */
/* Calls to AppProcess shall always alternate b/w ReaderData and CardData */
/* If there are 2 successive calls to to AppProcess with ReaderData, it means */
/* we have not received card data -> bad case */
/* So, we need always two calls to AppProcess to evaluate b/w good & bad case */
/* two calls are called a cycle further on */
/* we do increment the threshold after each cycle */
/* We store the first successfull card data as min_succ_th (means the threshold when we have received */
/* card data the first time */
/* And now we increment the threshold further, until we dont get card data anymore */
/* This will be stored in 'max_succ_th */
/* We do assume now, that the optimal threshold is between min_succ_th and max_succ_th */
/* With this approach we do avoid, to maintain a large array of possible thresholds */
/* The serach range is defined by the DemodFloorNoiseLevel */
/* We search b/w: */
/* 0.5 * DemodFloorNoiseLevel --> 1.5 * DemodFloorNoiseLevel */


/*
_________________________ scanning range ______________________________________
/ \
-|---------|-----------------------------------------threshold-----------------------------|------------>
| |
typical pattern| |
- bad case |------------------------+-++++-+-+---------------------------------------------|
+ good case | | | |
| min_succ_th | |
| max_succ_th |
min_th max_th
And finally the desired threshold is: (min_succ_th + max_succ_th) >> 1
*/
static uint16_t curr_th = 0;
static uint16_t min_th = 0;
static uint16_t max_th = 0xFFF;
static uint16_t min_succ_th = 0;
static uint16_t max_succ_th = 0xFFF;

static bool last_cycle_successful = false;

void SniffISO15693AppTimeout(void)
{
Expand All @@ -20,6 +71,7 @@ void SniffISO15693AppTimeout(void)
void SniffISO15693AppInit(void)
{
Sniff15693CurrentCommand = Sniff15693_Do_Nothing;
autocalib_state = AUTOCALIB_INIT;
}

void SniffISO15693AppReset(void)
Expand All @@ -38,17 +90,139 @@ void SniffISO15693AppTick(void)

}

INLINE void SniffISO15693InitAutocalib(void){
uint16_t floor_noise = SniffISO15693GetFloorNoise();
/* We search b/w: */
/* 0.5 * DemodFloorNoiseLevel --> 1.5 * DemodFloorNoiseLevel */
min_th = floor_noise >> 1;
max_th = floor_noise + (floor_noise >> 1);
if(min_th >= max_th) {
min_th = 0;
max_th = 0xFFF;
}

min_succ_th = 0;
max_succ_th = 0xFFF;

last_cycle_successful = false;
#ifdef ISO15693_DEBUG_LOG
{
char str[64];
sprintf(str, "Sniff15693: Start Autocalibration %d - %d ", min_th, max_th);
LogEntry(LOG_INFO_GENERIC, str, strlen(str));
}
#endif /*#ifdef ISO15693_DEBUG_LOG*/
curr_th = min_th;
CodecThresholdSet(curr_th);
return;
}

INLINE void SniffISO15693FinishAutocalib(void){
uint16_t new_th;
new_th = (min_succ_th + max_succ_th) >> 1;
CodecThresholdSet(new_th);
#ifdef ISO15693_DEBUG_LOG
{
char str[64];
sprintf(str, "Sniff15693: Finished Autocalibration %d - %d --> % d", min_succ_th, max_succ_th, new_th);
LogEntry(LOG_INFO_GENERIC, str, strlen(str));
}
#endif /*#ifdef ISO15693_DEBUG_LOG*/
SniffISO15693AppInit();
CommandLinePendingTaskFinished(COMMAND_INFO_OK_WITH_TEXT_ID, NULL);
//CommandLinePendingTaskFinished(COMMAND_INFO_FALSE_ID, NULL);
}

INLINE void SniffISO15693IncrementThreshold(void){

/* So increment the threshold */
/* Steps of 3*16=48 are sufficient for us */
curr_th += ISO15693_TH_CALIBRATE_STEPS;
CodecThresholdSet(curr_th);
#ifdef ISO15693_DEBUG_LOG
{
char str[64];
sprintf(str, "Sniff15693: Try next th=%d", curr_th);
LogEntry(LOG_INFO_GENERIC, str, strlen(str));
}
#endif /*#ifdef ISO15693_DEBUG_LOG*/
if(curr_th >= max_th) {
/* We are finished now */
/* Evaluate the results */
SniffISO15693FinishAutocalib();
}
}

uint16_t SniffISO15693AppProcess(uint8_t* FrameBuf, uint16_t FrameBytes)
{
#ifdef ISO15693_DEBUG_LOG
char str[64];
#endif
switch (Sniff15693CurrentCommand) {
case Sniff15693_Do_Nothing: {
return 0;
}
case Sniff15693_Autocalibrate: {
sprintf(str, "CMD: Sniff15693_Autocalibrate ");
LogEntry(LOG_INFO_GENERIC, str, strlen(str));
CommandLinePendingTaskFinished(COMMAND_INFO_FALSE_ID, NULL);
switch(autocalib_state){
case(AUTOCALIB_INIT):
SniffISO15693InitAutocalib();
if(SniffTrafficSource == TRAFFIC_CARD)
autocalib_state = AUTOCALIB_CARD_DATA;
else
autocalib_state = AUTOCALIB_READER_DATA;
break;
case(AUTOCALIB_READER_DATA): /* Means last time we have received reader data */
if(SniffTrafficSource == TRAFFIC_READER){
/* Second time Reader Data received */
/* This means no card data received */
/* If we had successful tries before */
/* we need to record it as threshold max here */
if(last_cycle_successful == true){
max_succ_th = GlobalSettings.ActiveSettingPtr->ReaderThreshold -
CODEC_THRESHOLD_CALIBRATE_STEPS;
#ifdef ISO15693_DEBUG_LOG
sprintf(str, "Sniff15693: Updated max_succ_th (%d) ", max_succ_th);
LogEntry(LOG_INFO_GENERIC, str, strlen(str));
#endif /*#ifdef ISO15693_DEBUG_LOG*/
}
last_cycle_successful = false;
}else{
/* We have received card data now */
/* Threshold is in a good range */
/* if min_succ_th was never set ( == 0) */
/* Set it now to the current threshold */
if (min_succ_th == 0)
min_succ_th = GlobalSettings.ActiveSettingPtr->ReaderThreshold;
last_cycle_successful = true;
#ifdef ISO15693_DEBUG_LOG
sprintf(str, "Sniff15693: Found card data (%d) ", min_succ_th);
LogEntry(LOG_INFO_GENERIC, str, strlen(str));
#endif /*#ifdef ISO15693_DEBUG_LOG*/
autocalib_state = AUTOCALIB_CARD_DATA;
}
SniffISO15693IncrementThreshold();
break;
case(AUTOCALIB_CARD_DATA): /* Means last time we have received card data */
if(SniffTrafficSource == TRAFFIC_CARD){
/* We have received card data now */
/* Threshold is in a good range */
/* if min_succ_th was never set ( == 0) */
/* Set it now to the current threshold */
if (min_succ_th == 0)
min_succ_th = GlobalSettings.ActiveSettingPtr->ReaderThreshold;
last_cycle_successful = true;
#ifdef ISO15693_DEBUG_LOG
sprintf(str, "Sniff15693: Found card data (%d) ", min_succ_th);
LogEntry(LOG_INFO_GENERIC, str, strlen(str));
#endif /*#ifdef ISO15693_DEBUG_LOG*/
SniffISO15693IncrementThreshold();
}else{
autocalib_state = AUTOCALIB_READER_DATA;
}
break;
default:
break;
}
return 0;
}
}
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