DIY Paper Entry and Exit Recorder

DIY Paper Entry and Exit Recorder

——BETCuser

In this project, we develop a paper entry and exit recorder using the BW21-CBV-Kit from Ai-Thinker and a thermal printing module. This device can recognize individuals through face detection and print out entry and exit records in real-time.

You can select a thermal printing module on your own from shopping platforms.

Hardware Connection

According to the official instructions of the thermal printing module, it can be connected using TTL, RS232, or USB modes. I chose the TTL connection mode with the BW21-CBV-Kit.

Based on the official documentation of the BW21-CBV-Kit, IOA2 and IOA3 correspond to UART1_TXD and UART1_RXD respectively.

Connect IOA2 to the RXD of the thermal printing module via a ribbon cable, and IOA3 to the TXD of the thermal printing module, to complete the basic hardware connection.

Software Implementation

To enable the Ameba BW21-CBV-Kit to output content normally, initialize Serial1.begin(115200);. When a face is detected, use Serial1.println(item.name()); to print the name of the detected person.

Complete Code

#include "WiFi.h"
#include "StreamIO.h"
#include "VideoStream.h"
#include "RTSP.h"
#include "NNFaceDetectionRecognition.h"
#include "VideoStreamOverlay.h"
#define CHANNEL   0
#define CHANNELNN 3
#define NNWIDTH  576
#define NNHEIGHT 320
VideoSetting config(VIDEO_FHD, 30, VIDEO_H264, 0);
VideoSetting configNN(NNWIDTH, NNHEIGHT, 10, VIDEO_RGB, 0);
NNFaceDetectionRecognition facerecog;
RTSP rtsp;
StreamIO videoStreamer(1, 1);
StreamIO videoStreamerFDFR(1, 1);
StreamIO videoStreamerRGBFD(1, 1);
char ssid[] = "SSID";
char pass[] = "password";
int status = WL_IDLE_STATUS;
String Last = " ";
IPAddress ip;
int rtsp_portnum;
void setup() {
Serial.begin(115200);
Serial1.begin(115200);
while (status != WL_CONNECTED) {
status = WiFi.begin(ssid, pass);
delay(2000);
}
ip = WiFi.localIP();
config.setBitrate(2 * 1024 * 1024);
Camera.configVideoChannel(CHANNEL, config);
Camera.configVideoChannel(CHANNELNN, configNN);
Camera.videoInit();
rtsp.configVideo(config);
rtsp.begin();
rtsp_portnum = rtsp.getPort();
facerecog.configVideo(configNN);
facerecog.modelSelect(FACE_RECOGNITION, NA_MODEL, DEFAULT_SCRFD, DEFAULT_MOBILEFACENET);
facerecog.begin();
facerecog.setResultCallback(FRPostProcess);
videoStreamer.registerInput(Camera.getStream(CHANNEL));
videoStreamer.registerOutput(rtsp);
if (videoStreamer.begin() != 0) {
//Serial.println("StreamIO link start failed");
}
Camera.channelBegin(CHANNEL);
videoStreamerRGBFD.registerInput(Camera.getStream(CHANNELNN));
videoStreamerRGBFD.setStackSize();
videoStreamerRGBFD.setTaskPriority();
videoStreamerRGBFD.registerOutput(facerecog);
if (videoStreamerRGBFD.begin() != 0) {
//Serial.println("StreamIO link start failed");
}
Camera.channelBegin(CHANNELNN);
OSD.configVideo(CHANNEL, config);
OSD.begin();
}
void loop() {
if (Serial.available() > 0) {
String input = Serial.readString();
input.trim();
if (input.startsWith(String("REG="))) {
String name = input.substring(4);
facerecog.registerFace(name);
} else if (input.startsWith(String("DEL="))) {
String name = input.substring(4);
facerecog.removeFace(name);
} else if (input.startsWith(String("RESET"))) {
facerecog.resetRegisteredFace();
} else if (input.startsWith(String("BACKUP"))) {
facerecog.backupRegisteredFace();
} else if (input.startsWith(String("RESTORE"))) {
facerecog.restoreRegisteredFace();
}
}
delay(2000);
OSD.createBitmap(CHANNEL);
OSD.update(CHANNEL);
}
void FRPostProcess(std::vector<FaceRecognitionResult> results) {
uint16_t im_h = config.height();
uint16_t im_w = config.width();
OSD.createBitmap(CHANNEL);
if (facerecog.getResultCount() > 0) {
for (int i = 0; i < facerecog.getResultCount(); i++) {
FaceRecognitionResult item = results[i];
int xmin = (int)(item.xMin() * im_w);
int xmax = (int)(item.xMax() * im_w);
int ymin = (int)(item.yMin() * im_h);
int ymax = (int)(item.yMax() * im_h);
uint32_t osd_color;
if (String(item.name()) == String("unknown")) {
osd_color = OSD_COLOR_RED;
} else {
osd_color = OSD_COLOR_GREEN;
if (Last != String(item.name())) {
Serial1.println(item.name());
Last = String(item.name());
}
}
OSD.drawRect(CHANNEL, xmin, ymin, xmax, ymax, 3, osd_color);
char text_str[40];
OSD.drawText(CHANNEL, xmin, ymin - OSD.getTextHeight(CHANNEL), text_str, osd_color);
}
}
OSD.update(CHANNEL);
}

When the BW21-CBV-Kit detects a registered face, it will output the corresponding name via the thermal printing module, achieving a paper-based entry and exit record.