Hello,
This is my first arduino project and I hop some of you will be able to solve my issue.
My hardware is : Arduino uno R4 wifi
I have bought an Adafruit fingerprint sensor and I managed to make everything works as desired when plugged in to my PC via USB C.
However when I try to only use a power supply (Outup 9-12.6V 4A) the fingerprint is not detected anymore.
Please find my code below :
#include <WiFiS3.h>
#include <PubSubClient.h>
#include <Adafruit_Fingerprint.h>
#include <ArduinoJson.h>
#include <Arduino_LED_Matrix.h>
#include <ArduinoGraphics.h>
#include "SoftwareSerial.h"
ArduinoLEDMatrix matrix;
const char* ssid = "******";
const char* password = "*****";
const char* mqtt_server = "*****";
const char* mqtt_topic = "******";
#define RELAY_PIN 4
#define ACCESS_DELAY 5000 // Keep lock unlocked for 5 seconds
// Define SoftwareSerial for Arduino UNO and similar boards
#define mySerial Serial1
//SoftwareSerial mySerial(2, 3);
Adafruit_Fingerprint finger = Adafruit_Fingerprint(&mySerial);
WiFiClient espClient;
PubSubClient client(espClient);
void setup() {
Serial.begin(9600);
matrix.begin();
litColumns(12, HIGH);
delay(100);
Serial.println("\n\nAdafruit finger detect test");
litColumns(11, HIGH);
finger.begin(57600);
delay(5);
// Connect to WiFi
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(1000);
Serial.println("Connecting to WiFi...");
}
Serial.println("Connected to WiFi");
litColumns(2, HIGH);
// Connect to MQTT broker
client.setServer("192.168.1.27", 1883);
client.setCallback(callback);
while (!client.connected()) {
if (client.connect("ArduinoClient")) {
client.subscribe(mqtt_topic);
Serial.println("Connected to MQTT broker");
blinkLED(2);
} else {
Serial.println("Failed to connect to MQTT broker. Trying again in 5 seconds...");
litColumns(3, HIGH);
delay(5000);
}
}
litColumns(2, HIGH);
if (finger.verifyPassword()) {
Serial.println("Found fingerprint sensor!");
} else {
Serial.println("Did not find fingerprint sensor :(");
litColumns(0, HIGH);
while (1) { delay(1); }
}
litColumns(10, HIGH);
pinMode(RELAY_PIN, OUTPUT);
digitalWrite(RELAY_PIN, LOW);
Serial.println(F("Reading sensor parameters"));
finger.setSecurityLevel(1);
finger.getParameters();
Serial.print(F("Status: 0x"));
Serial.println(finger.status_reg, HEX);
Serial.print(F("Sys ID: 0x"));
Serial.println(finger.system_id, HEX);
Serial.print(F("Capacity: "));
Serial.println(finger.capacity);
Serial.print(F("Security level: "));
Serial.println(finger.security_level);
Serial.print(F("Device address: "));
Serial.println(finger.device_addr, HEX);
Serial.print(F("Packet len: "));
Serial.println(finger.packet_len);
Serial.print(F("Baud rate: "));
Serial.println(finger.baud_rate);
finger.getTemplateCount();
if (finger.templateCount == 0) {
Serial.print("Sensor doesn't contain any fingerprint data. Please run the 'enroll' example.");
} else {
Serial.println("Waiting for valid finger...");
Serial.print("Sensor contains ");
Serial.print(finger.templateCount);
Serial.println(" templates");
}
litColumns(1, HIGH);
}
void loop() {
client.loop();
if (getFingerPrint() != -1) {
// Send MQTT message when the condition is met
Serial.println("sending..");
client.publish(mqtt_topic, "{\"id\":\"Malette\",\"state\":\"SOLVED\"}");
Serial.println("MQTT message sent.");
blinkLED(2);
digitalWrite(RELAY_PIN, HIGH);
delay(ACCESS_DELAY);
digitalWrite(RELAY_PIN, LOW);
Serial.println("Success");
}
delay(50); // don't need to run this at full speed
}
uint8_t getFingerprintID() {
uint8_t p = finger.getImage();
switch (p) {
case FINGERPRINT_OK:
Serial.println("Image taken");
break;
case FINGERPRINT_NOFINGER:
Serial.println("No finger detected");
return p;
case FINGERPRINT_PACKETRECIEVEERR:
Serial.println("Communication error");
return p;
case FINGERPRINT_IMAGEFAIL:
Serial.println("Imaging error");
return p;
default:
Serial.println("Unknown error");
return p;
}
// OK success!
p = finger.image2Tz();
switch (p) {
case FINGERPRINT_OK:
Serial.println("Image converted");
break;
case FINGERPRINT_IMAGEMESS:
Serial.println("Image too messy");
return p;
case FINGERPRINT_PACKETRECIEVEERR:
Serial.println("Communication error");
return p;
case FINGERPRINT_FEATUREFAIL:
Serial.println("Could not find fingerprint features");
return p;
case FINGERPRINT_INVALIDIMAGE:
Serial.println("Could not find fingerprint features");
return p;
default:
Serial.println("Unknown error");
return p;
}
// OK converted!
p = finger.fingerSearch();
if (p == FINGERPRINT_OK) {
Serial.println("Found a print match!");
} else if (p == FINGERPRINT_PACKETRECIEVEERR) {
Serial.println("Communication error");
return p;
} else if (p == FINGERPRINT_NOTFOUND) {
Serial.println("Did not find a match");
return p;
} else {
Serial.println("Unknown error");
return p;
}
// found a match!
Serial.print("Found ID #");
Serial.print(finger.fingerID);
Serial.print(" with confidence of ");
Serial.println(finger.confidence);
return finger.fingerID;
}
// returns -1 if failed, otherwise returns ID #
int getFingerprintIDez() {
uint8_t p = finger.getImage();
if (p != FINGERPRINT_OK) return -1;
p = finger.image2Tz();
if (p != FINGERPRINT_OK) return -1;
p = finger.fingerFastSearch();
if (p != FINGERPRINT_OK) return -1;
// found a match!
Serial.print("Found ID #");
Serial.print(finger.fingerID);
Serial.print(" with confidence of ");
Serial.println(finger.confidence);
return finger.fingerID;
}
// returns -1 if failed, otherwise returns ID #
int getFingerPrint() {
int p = finger.getImage();
if (p != FINGERPRINT_OK) return -1;
p = finger.image2Tz();
if (p != FINGERPRINT_OK) return -1;
p = finger.fingerFastSearch();
if (p != FINGERPRINT_OK) return -1;
// found a match!
return finger.fingerID;
}
// Function to blink the LED a specified number of times
void blinkLED(int numBlinks) {
for (int i = 0; i < numBlinks; i++) {
// Turn on the LED
finger.LEDcontrol(true);
delay(500); // Adjust the delay based on your preference for blink speed
// Turn off the LED
finger.LEDcontrol(false);
delay(500); // Adjust the delay based on your preference for blink speed
}
}
void callback(char* topic, byte* payload, unsigned int length) {
Serial.println("Message received on topic: " + String(topic));
// Parse JSON payload
DynamicJsonDocument jsonDoc(1024); // Adjust the size based on your JSON payload
deserializeJson(jsonDoc, payload, length);
// Access JSON data
const char* id = jsonDoc["id"];
const char* command = jsonDoc["command"];
// Do something with the data
Serial.println("ID: " + String(id));
Serial.println("Command: " + String(command));
// Check if ID is "Malette" and command is "SOLVED"
if (strcmp(id, "Malette") == 0 && strcmp(command, "SOLVED") == 0) {
Serial.println("Triggering relay...");
digitalWrite(RELAY_PIN, HIGH); // Turn ON the relay
client.publish(mqtt_topic, "{\"id\":\"Malette\",\"state\":\"SOLVED\"}");
delay(5000); // Keep the relay ON for 5 seconds (adjust as needed)
digitalWrite(RELAY_PIN, LOW); // Turn OFF the relay
Serial.println("Relay triggered and turned off.");
}
}
void litColumns(int column, int state) {
if (column < 0 || column >= 12) {
Serial.println("Invalid column number");
return;
}
// Define a frame with the specified column lit up
uint8_t frame[8][12] = {
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }
};
for (int row = 0; row < 8; row++) {
for (int col = 0; col < column && col < 12; col++) {
frame[row][col] = 1;
}
}
// Load and display the frame
matrix.renderBitmap(frame, 8, 12);
}
I read different topics and I think my issue maybe here :
#define mySerial Serial1
because I read in one post that the Rx/Tx pins on the UNO WiFi Rev4 are Serial1, not Serial.
But I dont understand why it is only working when i am plugged in USB to my PC
Thank you again for your help, sorry in advance I am still learning Arduino and have a good day 
