CCD Camera Imaging Software for Moravian Instruments Cameras

This is an attempt to build a standalone imaging service running on Raspberry Pi that can be remotely controlled with a web browser.

Goals

Web application GUI for

• easy composition of the whole image
• focusing the image
• setting camera cooling parameters
• controlling batch imaging

Service

• running on a PC or Raspberry PI
• allowing standalone batch imaging

Stage of the Project

Project is almost ready for first field test, following features are already implemented:

• camera image preview (full, center 1:1 and corners 1:1)
• setting camera gain and exposure time
• camera cooling
• external PWM-controlled output for telescope heating
• histograms for RGB channels
• saving series of FITS files on the disk/memory card
• software power off of the device
• external input (trigger) for auto guider / remote control
• status LEDs

Images

Working proof of concept - the following image shows CCD camera powered with a power bank connected to a Raspberry PI 3 microcomputer running the control and web service. Android tablet runs the web interface and is already able to take image exposure and present it in the GUI.

Example gui for image composition, focusing and camera parameters (demo mode with generated fractal image):

Supported platforms

Software now runs on:

• linux PC (x86_64)
• Raspberry PI 3 (armv7)
• Raspberry PI 4 (aarch64)

Technologies

Project uses following drivers / technologies

• official gxccd driver for moravian cameras written in C, wrapper for Rust was developed with help of bindgen for generating Rust headers
• server uses warp and tokio
• client is written in yew and is compiled into WebAssembly

Installing Dependencies to build Web Service

In order to build the web service, following debian packages are needed

apt install libusb-1.0-0-dev llvm-dev libclang-dev clang libcfitsio-dev

Web service in the repository already contains client WASM binaries compiled previously, so it is only needed to build the web service on the target platform.

Service compiled on Raspberry PI 3 equipped with 1 GB od RAM without problems so i did not bother with crosscompiling it.

To run the web service, run:

cd ccdi-web-service
cargo run --release

Installing Dependencies for Web Client Development

To install the trunk server (dev server for hosting and reloading web service upon change), type:

cargo install --locked trunk

To run the client in the dev server, run:

cd ccdi-web-client
trunk serve --release --open

Enabling permissions for moravian camera

In case of the following error: [gxccd] error: my_libusb_open(): libusb_open failed: -3, LIBUSB_ERROR_ACCESS

Current user does not have sufficient permissions to work with the camera.

Create text file /etc/udev/rules.d/98-moravian.rules

And insert the following content

# Moravian camera
ATTRS{idVendor}=="1347", ATTRS{idProduct}=="0ca0", MODE:="0666"

Reload UDEV rules and reconnect the device

• sudo udevadm control --reload-rules
• OR sudo systemctl restart udev

Notes

Tool to view FITS images: QFitsView - sudo apt install qfitsview