Skip to content

bezineb5/RoboScan

Repository files navigation

RoboScan

This is the source code for a Lego+Raspberry Pi-powered analog film roll scanner. Watch it in action: RoboScan Demonstration

Parts

You'll need these items to build RoboScan:

Part 1: Wiring

Diagram

Roboscan wiring diagram

(made using Fritzing with the help of parts from e-radionica.com and Blomquist)

ULN2003A wiring

Put a 50V, 47 μF capacitor between the LED+ and LED - pins of the driver.

ULN2003A Stepper Motor driver Raspberry Pi
IN1 GPIO 5
IN2 GPIO 6
IN3 GPIO 13
IN4 GPIO 19
POWER+ 5V power (such as the one next to the Ground)
POWER - Ground (such as the one next to the 5V power)

Recom Power RCD-24-0.70/PL/B Backlight LED driver wiring

Recom Power RCD-24-0.70/PL/B Raspberry Pi
1 - +Vin 5V power (the one not already used by the stepper motor)
3 - PWM/ON/OFF GPIO 18
4 - GND Ground (such as the one next to the GPIO 18)

Alternative: Sparkfun FemtoBuck Backlight LED driver wiring

Untested - make sure to solder the jumper that can be closed with a glob of solder to double the output current from 330mA to 660mA.

Sparkfun FemtoBuck LED Driver Raspberry Pi
V-/PGND Ground (any remaining)
V+/VIN 5V power (the one not already used by the stepper motor)
D-/DGND Ground (such as the one next to the GPIO 18)
D+/CTRL GPIO 18

Part 2: Software installation

Prepare the Raspberry Pi

Follow Raspberry foundation documentation, such as: https://projects.raspberrypi.org/en/projects/raspberry-pi-setting-up. Tip: you can set the hostname of your Raspberry Pi to "piscanner" as it's what's used in this tutorial. You can use raspi-config for this.

Install Docker

The easiest is to use the "convenience script" as described here: https://docs.docker.com/engine/install/debian/#install-using-the-convenience-script.

In a nutshell:

curl -fsSL https://get.docker.com -o get-docker.sh
sudo sh get-docker.sh
# Add your user to the docker group
sudo groupadd docker
sudo usermod -aG docker $USER

Install Python & PIP

On Raspbian, the easiest is to install it through Python's pip:

# Install Python3 and pip
sudo apt install python3 python3-pip

Clone this repository on your Raspberry Pi

git clone https://github.com/bezineb5/RoboScan.git
cd RoboScan

Start the application

Now, you will ask docker to build and start the application. This might take a while (30-120 minutes).

cd docker
docker compose up -d --build

It will start all components and restart them at reboot.

Part 3: Using RoboScan

The camera must be connected to the Raspberry Pi via USB. It must be compatible with libgphoto2.

Connect to the web interface

Simply navigate to http://piscanner/ (adjust the hostname to your Raspberry Pi)

Optional: Google Coral TPU

You can improve the machine learning inference performance by using a Google Coral Edge TPU USB Accelerator plugged on a USB port of the Raspberry Pi. To do so, you have to change the file src/Dockerfile. Replace:

CMD ["python", "webapp.py", "--destination", "/storage/share", "--archive", "/storage/archive", "--temp", "/storage/tmp"]

by:

CMD ["python", "webapp.py", "-tpu", "--destination", "/storage/share", "--archive", "/storage/archive", "--temp", "/storage/tmp"]

Optional: for developers

The easiest is to code on you PC and deploy docker containers remotely. To do so, enable remote access to the docker daemon.

# Set the DOCKERHOST variable (only once)
# Adjust the hostname to your Raspberry Pi
export DOCKER_HOST=tcp://piscanner.local:2376 DOCKER_TLS_VERIFY=

# Then deploy as usual
cd docker
docker compose up -d
cd ..