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Retry SAMConfiguration command to fix the 'Unable to read ACK' issue.

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Refer to PN532 User Manual 6.2.3:

"In the case the host controller does not detect an ACK frame within
these 15 ms, the host controller should resend the same command frame."

so here retry SAM command, it will fix the 'Unable to read ACK' issus.
This commit is contained in:
sam 2017-08-14 17:40:53 +08:00
parent 2869ae2eb8
commit 6774231e3d
1 changed files with 9 additions and 1 deletions
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10
libnfc/drivers/pn532_uart.c
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@ -324,7 +324,15 @@ pn532_uart_send(nfc_device *pnd, const uint8_t *pbtData, const size_t szData, in
return res;
}
// According to PN532 application note, C106 appendix: to go out Low Vbat mode and enter in normal mode we need to send a SAMConfiguration command
if ((res = pn532_SAMConfiguration(pnd, PSM_NORMAL, 1000)) < 0) {
for (int i = 0; i < 10; i++) {
res = pn532_SAMConfiguration(pnd, PSM_NORMAL, 20);
if (res == NFC_ETIMEOUT) {
log_put(LOG_GROUP, LOG_CATEGORY, NFC_LOG_PRIORITY_ERROR, "%s", "Command SAMConfiguration timeout, retry...");
} else {
break;
}
}
if (res < 0) {
return res;
}
}