Old raspberry PI webcam & ESP32 integration

Reviving Old Raspberry Pi: Webcam & ESP32 Integration

The world of technology is constantly evolving, with new devices and innovations emerging every day. However, this doesn’t mean that older devices are no longer useful. In fact, many older devices can still be repurposed and used for a variety of tasks. One such device is the Raspberry Pi Model B Rev. 2, a single-board computer that was first released in 2012. In this article, we will explore how to revive an old Raspberry Pi and use it for webcam experiments and ESP32 integration.

Introduction to Raspberry Pi

The Raspberry Pi is a series of small, low-cost, and highly capable single-board computers that were designed to promote the teaching of computer science and programming. The Raspberry Pi Model B Rev. 2 is one of the earlier models, featuring a 700 MHz single-core CPU, 512 MB of RAM, and two USB 2.0 ports. While it may not be as powerful as newer models, it is still a capable device that can be used for a variety of tasks.

Exploring Webcam Experiments

One of the first things we wanted to try with our old Raspberry Pi was using it with a webcam. We started by researching which Raspberry Pi models come with built-in Wi-Fi, as this would be a handy feature for modern projects. We found that the Raspberry Pi 3 Model B, Raspberry Pi 4 Model B, Raspberry Pi 5, Raspberry Pi Zero W, and Raspberry Pi Zero 2 W all have built-in Wi-Fi. However, our Model B Rev. 2 does not have Wi-Fi, so we would need to use a USB Wi-Fi adapter or Ethernet for network access.

Next, we wondered if our old Pi could work with a USB webcam. The short answer is yes, but with limits. The Raspberry Pi Model B Rev. 2 has two USB 2.0 ports and a sluggish 700 MHz single-core CPU, so it’s not a powerhouse. However, it can manage basic video monitoring, timelapse photography, and motion detection. The catch is that USB power delivery is weak, so a powered USB hub might be needed for hungrier webcams. Also, it needs a UVC-compatible camera, such as a Logitech C270.

Discovering the CSI Port

As we continued to explore our old Raspberry Pi, we discovered that it has a CSI (Camera Serial Interface) port. This port is perfect for official Raspberry Pi camera modules, and it offloads video processing from the CPU, making it more efficient for this old hardware. We found a 5MP camera module with a 175° wide-angle lens that is compatible with our Model B Rev. 2’s 15-pin CSI slot.

With this setup, we could capture 5MP stills, stream low-res video, and monitor a wide area thanks to the fish-eye lens. Setup was simple: we just had to plug in the ribbon cable, enable the camera in `raspi-config`, and test with `raspistill -o test.jpg`. It worked like a charm, although 1080p video was too much for the Pi’s modest specs.

Pricing and Comparison

We were curious about the costs of different Raspberry Pi models, so we checked prices and weights:
– Raspberry Pi Model B Rev. 2: ~50-100 PLN (used), 45g
– Raspberry Pi 4 (4 GB): 300-350 PLN, 46g
– Raspberry Pi Zero 2 W: 120-150 PLN, 9g
– Camera Module (5MP): ~100-150 PLN

Our old Pi was basically free since we already had it, and the camera was a worthwhile investment.

Integrating with ESP32

As we continued to experiment with our old Raspberry Pi, we decided to integrate it with an ESP32. The ESP32 is a microcontroller that has built-in Wi-Fi and Bluetooth capabilities, making it perfect for IoT projects. We used the ESP32 to create a web server that could receive and display images from the Raspberry Pi.

We connected the Raspberry Pi to the ESP32 using a serial connection, with the Raspberry Pi’s GPIO 14 (TXD) connected to the ESP32’s GPIO 16 (RXD2), and the Raspberry Pi’s GPIO 15 (RXD) connected to the ESP32’s GPIO 17 (TXD2). We also connected the ground pins of both devices.

On the Raspberry Pi side, we used Python to send the image file to the ESP32:

import serial
import time

ser = serial.Serial('/dev/ttyS0', 115200, timeout=1)
def send_file(file_path):
    with open(file_path, 'rb') as f:
        ser.write(b'START\n')
        ser.write(f.read())
        ser.write(b'END\n')
    print("File sent!")
send_file('test.jpg')
ser.close()

On the ESP32 side, we used Arduino to receive the image file and display it on a web server:

include 
include "FS.h"
include "SPIFFS.h"

HardwareSerial Serial2(2); // UART2 on GPIO 16/17
void setup() {
  Serial.begin(115200);
  Serial2.begin(115200);
  SPIFFS.begin(true);
}

void loop() {
  static bool receiving = false;
  static File file;
  if (Serial2.available()) {
    String line = Serial2.readStringUntil('\n');
    if (line == "START") {
      receiving = true;
      file = SPIFFS.open("/image.jpg", FILE_WRITE);
    } else if (line == "END" && receiving) {
      file.close();
      receiving = false;
      Serial.println("File saved");
    } else if (receiving) {
      file.write((uint8_t*)line.c_str(), line.length());
    }
  }
}

We also added a route to the ESP32’s web server to display the received image:

server.on("/image", HTTP_GET, [](){
  File file = SPIFFS.open("/image.jpg", "r");
  server.streamFile(file, "image/jpeg");
  file.close();
});

Now, after snapping a photo with `raspistill`, we can send it to the ESP32, and it’s viewable at `http:///image`. For more information on this project, you can visit the source URL as a reference.

Lessons Learned

Throughout this project, we learned several valuable lessons:
– Performance: UART at 115200 bps is slow (~11 KB/s), so a 100 KB JPG takes ~9 seconds. This is fine for small files, but less so for big ones.
– Old Tech Rocks: Our 2012 Pi still shines for basic tasks, proving that old devices can still be useful.
– Wired Wins: Skipping Wi-Fi simplified things with this setup, making it more reliable and efficient.

What’s Next?

We could tweak the ESP32 to trigger motor actions based on the image (e.g., motion detection), but for now, we’re thrilled to breathe new life into this old Pi. If you have an ancient Raspberry Pi lying around, dig it out – you might be surprised what it can still do!

In conclusion, reviving an old Raspberry Pi can be a fun and rewarding project. With a little creativity and experimentation, you can breathe new life into an old device and use it for a variety of tasks. Whether you’re a seasoned maker or just starting out, we hope this article has inspired you to explore the possibilities of old technology. So, what are you waiting for? Get out there and start tinkering!