Firmware flow
How a fingerprint is checked
Fingerprint verification routine.
Wait for an image, convert it to a fingerprint template and search stored records. A conversion error stops the routine; the search reports either a matching ID and confidence or a no-match error.
The function waits for an image without a timeout in the supplied code. It reports search results, not an independently measured recognition rate.
Read the implementation
verifyReload · selected source lines 260–280. Source inspection is not a hardware test.
void verifyReload() {
Serial.println(F("❓ Verify: place the same finger…"));
// 1) wait for finger
while (finger.getImage() != FINGERPRINT_OK) delay(50);
if (finger.image2Tz(1) != FINGERPRINT_OK) {
Serial.println(F("⚠️ image2Tz fail"));
return;
}
// 2) search the buffer 1 template against slot 1
uint8_t res = finger.fingerFastSearch();
if (res == FINGERPRINT_OK) {
Serial.print(F("✅ Match! ID="));
Serial.print(finger.fingerID);
Serial.print(F(" Confidence="));
Serial.println(finger.confidence);
} else {
Serial.print(F("❌ No match (err 0x"));
Serial.print(res, HEX);
Serial.println(F(")"));
}
}Technical notes
Sensor connection
sensorSerialBegin() provides a communication setup step separate from fingerprint enrolment and verification. This keeps transport handling identifiable.
Fingerprint enrolment
enrollFingerprint() handles registration separately from later fingerprint checks.
Stored model handling
downloadModelToString() and reloadFingerprint() handle model representation and reloading separately from matching a presented fingerprint.