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defined stop condition for reading processes, otherwise pm 'crashes' if there's no tag on device

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tharexde 2020-06-28 21:31:39 +02:00
parent 81cd478883
commit 9ce9a82803
1 changed files with 87 additions and 66 deletions
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153
armsrc/em4x50.c
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@ -75,6 +75,7 @@ static em4x50_tag_t tag = {
#define EM4X50_T_WAITING_FOR_LIW 500
#define EM4X50_T_TAG_TPP 64
#define EM4X50_T_TAG_TWA 64
#define EM4X50_T_TAG_INIT 2112
#define EM4X50_TAG_TOLERANCE 8
#define EM4X50_TAG_WORD 45
@ -237,19 +238,34 @@ static void em4x50_setup_read(void) {
// functions for "reader" use case
static void get_signalproperties(void) {
static bool get_signalproperties(void) {
// calculate signal properties (mean amplitudes) from measured data:
// 32 amplitudes (maximum values) -> mean amplitude value -> gHigh -> gLow
bool signal_found = false;
int no_periods = 32, pct = 75, noise = 140;
uint8_t sample = 0, sample_ref = 127;
uint8_t sample_max_mean = 0;
uint8_t sample_max[no_periods];
uint32_t sample_max_sum = 0;
// wait until signal/noise > 1
while (AT91C_BASE_SSC->SSC_RHR < noise);
// wait until signal/noise > 1 (max. 32 periods)
for (int i = 0; i < T0 * no_periods; i++) {
// about 2 samples per bit period
wait_timer(0, T0 * EM4X50_T_TAG_HALF_PERIOD);
if (AT91C_BASE_SSC->SSC_RHR > noise) {
signal_found = true;
break;
}
}
if (!signal_found)
return false;
// calculate mean maximum value of 32 periods, each period has a length of
// 3 single "full periods" to eliminate the influence of a listen window
@ -274,6 +290,7 @@ static void get_signalproperties(void) {
gHigh = sample_ref + pct * (sample_max_mean - sample_ref) / 100;
gLow = sample_ref - pct * (sample_max_mean - sample_ref) / 100;
return true;
}
static int get_next_bit(void) {
@ -736,31 +753,32 @@ void em4x50_info(em4x50_data_t *etd) {
init_tag();
em4x50_setup_read();
// set gHigh and gLow
get_signalproperties();
if (etd->pwd_given) {
if (get_signalproperties()) {
// try to login with given password
blogin = login(etd->password);
if (etd->pwd_given) {
} else {
// if no password is given, try to login with "0x00000000"
blogin = login(password);
// try to login with given password
blogin = login(etd->password);
} else {
// if no password is given, try to login with "0x00000000"
blogin = login(password);
}
bsuccess = selective_read(addresses);
}
bsuccess = selective_read(addresses);
status = (bsuccess << 1) + blogin;
lf_finalize();
reply_ng(CMD_ACK, status, (uint8_t *)tag.sectors, 238);
}
void em4x50_sread(em4x50_data_t *etd) {
void em4x50_read(em4x50_data_t *etd) {
// reads in two different ways:
// - using "selective read mode" -> bidirectional communication
@ -776,25 +794,26 @@ void em4x50_sread(em4x50_data_t *etd) {
em4x50_setup_read();
// set gHigh and gLow
get_signalproperties();
if (get_signalproperties()) {
if (etd->addr_given) {
if (etd->addr_given) {
// selective read mode
// try to login with given password
if (etd->pwd_given)
blogin = login(etd->password);
// only one word has to be read -> first word read = last word read
addresses[2] = addresses[3] = etd->address;
bsuccess = selective_read(addresses);
} else {
// standard read mode
bsuccess = standard_read(&now);
// selective read mode
// try to login with given password
if (etd->pwd_given)
blogin = login(etd->password);
// only one word has to be read -> first word read = last word read
addresses[2] = addresses[3] = etd->address;
bsuccess = selective_read(addresses);
} else {
// standard read mode
bsuccess = standard_read(&now);
}
}
status = (now << 2) + (bsuccess << 1) + blogin;
@ -896,40 +915,41 @@ void em4x50_write(em4x50_data_t *etd) {
em4x50_setup_read();
// set gHigh and gLow
get_signalproperties();
if (get_signalproperties()) {
// reorder word according to datasheet
msb2lsb_word(etd->word);
// if password is given try to login first
if (etd->pwd_given)
blogin = login(etd->password);
// write word to given address
if (write(etd->word, etd->address)) {
// reorder word according to datasheet
msb2lsb_word(etd->word);
// if password is given try to login first
if (etd->pwd_given)
blogin = login(etd->password);
// write word to given address
if (write(etd->word, etd->address)) {
// to verify result reset EM4x50
if (reset()) {
// to verify result reset EM4x50
if (reset()) {
// if password is given login
if (etd->pwd_given)
blogin &= login(etd->password);
// if password is given login
if (etd->pwd_given)
blogin &= login(etd->password);
// call a selective read
addresses[2] = addresses[3] = etd->address;
if (selective_read(addresses)) {
// call a selective read
addresses[2] = addresses[3] = etd->address;
if (selective_read(addresses)) {
// compare with given word
word[0] = tag.sectors[etd->address][0];
word[1] = tag.sectors[etd->address][1];
word[2] = tag.sectors[etd->address][2];
word[3] = tag.sectors[etd->address][3];
msb2lsb_word(word);
bsuccess = true;
for (int i = 0; i < 4; i++)
bsuccess &= (word[i] == etd->word[i]) ? true : false;
// compare with given word
word[0] = tag.sectors[etd->address][0];
word[1] = tag.sectors[etd->address][1];
word[2] = tag.sectors[etd->address][2];
word[3] = tag.sectors[etd->address][3];
msb2lsb_word(word);
bsuccess = true;
for (int i = 0; i < 4; i++)
bsuccess &= (word[i] == etd->word[i]) ? true : false;
}
}
}
}
@ -950,11 +970,12 @@ void em4x50_write_password(em4x50_data_t *etd) {
em4x50_setup_read();
// set gHigh and gLow
get_signalproperties();
if (get_signalproperties()) {
// login and change password
if (login(etd->password)) {
bsuccess = write_password(etd->password, etd->new_password);
// login and change password
if (login(etd->password)) {
bsuccess = write_password(etd->password, etd->new_password);
}
}
lf_finalize();