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DVTI Camera Wiki

Project overview

The goal of the DVTI camera project is to develop a digital video camera targeted mainly at observing star occultations, with the following attributes:

  • precise GPS timestamp from integrated GPS receiver module
  • highly sensitive monochrome image sensor
  • continuous improvement of hard- and software through feedback from the community
  • price as low as possible

The development team consists of Stefan Meister and Andreas Schweizer. 

To reach the goal of a low price, we plan to initiate a Kickstarter campain later in 2019 so that components can be manufactured and bought at reasonable prices. In addition, as we develop the camera in our spare time, the time for R&D won't add to the camera price.

More information is available in the SOTAS (Stellar Occultation Timing Association) Switzerland presentation slides from Oct 2018 and the ESOP XXXVIII presentation slides from Aug 2019.

Project timeline

The current planning contains the following project phases:

  • proof-of-concept (modification of an existing camera ASI120MM, by adding an external digital time inserter module) - completed
  • prototype version 1 (standalone camera, based on an On Semi AR0130CSSM sensor) - completed
  • firmware development and testing for prototype version 1 - completed
    • On the host side, we'd like to provide an ASCOM video driver for the camera. (ASCOM video driver project seems to have been abandoned)
    • It should be possible to save SER files with GPS timestamps in the metadata.
    • The control tool should be extended to support 16-bit SER recording, histogram, dark and flat frame subtraction
  • Prototyp Version 2 (standalone camera, based on community feedback and experience with prototype version 1) - completed
    • The re-designed camera contains a large number of new components (USB-C, microSD, new GPS module, RAM, new FPGA, RF switch and so on). V2 is without RAM and SD card, but with rugged USB C connector. For V3, the design will be completed and condensed.
  • firmware development and testing for prototype version 2 - completed
    • All components of the new hardware platform are working fine, except for the integrated GPS antenna of the GPS module. The rugged USB-C connector is causing some soldering issues because the pin spacing is very narrow, pins are extremely thin and need to be cut to avoid stubs which cause reflection on the USB3 pins. One of the LVDS channels has been placed on the wrong FPGA bank, causing issues with clock supply and limiting the frame rate. 
    • Firmware for the IMX174 is available. This version supports the full WUXGA resolution of the chip (1920 x 1200). The frame rate is limited to 30fps due to a technical issue of the V2 board. The timestamp should be accurate to +/-0.5ms, testet with our EXTA. See the separate page for IMX174 firmware progress.
    • We've decided to use the IMX178 instead of AR0130 in the final release of the camera. This sensor is only slightly more expensive but the field of view is nearly twice as big. 
  • Prototype Version 3 (release candidate) - ongoing
    • Changes vs. version 2: Drop internal GPS antenna, add GPIO interface, add 256 MBytes DDR2 RAM buffer, change to a 0.8mm pitch FPGA, fix LVDS channel placing, improve power management, reduce startup time, switch to more stable oscillators (SiT5000)
    • The PCB has arrived and a first unit has been soldered. Hardware bring-up is ongoing. The power supply board is working fine, power sequencing has been implemented. In addition, the basic functionalities of the USB controller and the FPGA are working as expected. The flash memory can be programmed and the USB controller and FPGA can be configured from flash memory. Two minor design issues have been identified so far (missing connection, weak via) which can easily be fixed on the prototype.
    • The milling of the camera case is delayed but should take place in the first half of July.
  • kickstarter campain - ongoing
    • We're currently working on determining the camera options and prices.

News

08.07.2020 Another important step in the hardware bring-up of V3 has been successfully implemented today. The system and USB controller firmwares now successfully work together to first boot the USB controller and afterwards the FPGA from a combined firmware package in the shared flash memory. Due to the way the process works, we've been able to reduce the start-up time from about 10 seconds in the prototype V2 to less than 1 second. Follow this link for technical details about how this works and this link for photos about the hardware bring-up.

30.06.2020 Good news! The hardware bring-up of the V3 prototype is ongoing. A simple design loaded on the FPGA is working, and the integrated AD converter shows that the temperature and voltages are in range. In addition, a first USB3 lane is also working. The next step in the hardware bring-up is to load this test design on the SPI flash via USB controller.

14.06.2020 Hardware bring-up for a first V3 prototype has started. Power sequencing is working fine. The USB controller responds, the USB2 connection functions as expected. A next step is to verify USB3 functionality, and afterwards, the FPGA will be verified.

02.06.2020 The PCBs for prototype version 3 have arrived. Soldering and testing will start this week.

19.05.2020 PCB design for the prototype version 3 is complete and the PCB is currently in production. The design of the camera case is ongoing and should also be completed in the coming days. 

05.05.2020 We're finalizing the next version (4.9) of the camera control tool which will include support for local plate solving via ansvr, improved zooming and scrolling in the preview window, a first ASCOM integration to synchronize and control the telescope and various other improvements and bug fixes. PCB design for the prototype version 3 which is our "release candidate" for the kickstarter project should also be completed in the next few days.

13.02.2020 The upcoming version 4.8 of the camera control tool will include a couple of new features: Integration with OccultWatcher so that you can forward the event data from OW into the control tool; integration with nova.astrometry.net so that you can plate-solve what you see; support for ADV files, including multi-ROI ADV files; support for FITS series; support for skipping frames during recording. These features will be extended further in upcoming releases. Stefan is currently testing the new version of the control tool and we plan to release it for beta-testing soon.

12.02.2020 A couple of new IMX174 sensors have arrived. We plan to replace all AR0130 sensors with IMX174 in the beta testing cameras and drop support for the AR0130. 

24.01.2020 We've prioritized the implementation of recording ADV files so that the position of the timestamp within the frame can be more clearly defined than with SER. An updated version of the control tool will soon be ready for testing. In addition, starting at the next release, the camera should be more tolerant to connection issues during firmware updates, i.e. a new firmware won't directly overwrite the existing firmware on the camera but be written into a separate location and "activated" if the download into the camera has completed.

11.01.2020 We've been busy the past few weeks fixing issues reported by our beta testers, especially problems with Windows 7 and USB 2. A new DVTI control tool and new firmware images contain these fixes. There are still a few open points, but we've nevertheless started designing the "release candidate" V3 version of the camera in parallel.

09.12.2019 "Technical" first light with the IMX178 was successful. There's a new wiki page for IMX178 firmware development.

05.12.2019 We're working on the hardware bring-up for the IMX178 sensor board. There's a minor issue with missing pull-down resistors on power-enable lines, and the VHDL code for the power-up state needs to be improved, but no blocking issues so far...

27.11.2019 Firmware development for the IMX178 has started. The goal is to know before Christmas whether the camera with the small chip should include the AR0130 or the IMX178. The IMX178 is technically very similar to the IMX174, e.g. same LVDS interface standard, same gain options (0..24dB analog, 24..48dB digital). Compared to the IMX174, it has more (3072x2048 vs. 1920x1200) but smaller (2.4um vs. 5.86um) pixels. At 4x4 binning (9.6um pixels), the frame size will still be 768x512. This sensor offers a 14-bit A/D converter option which we'll ignore at the moment.

23.11.2019 Firmware versions 0.3.20 and 0.4.20-beta are available in the files section. Check the release notes to see what has been improved. In addition, the camera control tool has also been updated. The new version statically links to MFC and should work without installing the VC++ redistributable package.

19.11.2019 IMX174 first and second light have been successful. The firmware is still not on the same level as the one for the AR0130 but it's catching up. Firmware 0.4.20 will increase the maximum frame rate from 20 to 30 fps and allow for exposure times shorter than the frame time, down to 1ms. IMX178 boards should arrive this week. In parallel, we're working on setting up the Kickstarter project. Depending on tests with the IMX178, we'll decide whether to offer the "small" camera with the AR0130 or with the IMX178.

23.10.2019 To test if the IMX178 could be an alternative to the AR0130, we're working on an IMX178 sensor module for prototype V2. Technically, the sensor is similar to the IMX174.

22.10.2019 We've started testing version 0.4.17-alpha of the IMX174 firmware. See the new wiki page on IMX174 firmware progress.

05.10.2019 Version 4.3.6 of the DVTI Cam Control Software is available in the Files section. This version adds several new features such as automatic start of streaming, toolbar buttons, dark frame pedestal and more.

02.10.2019 Firmware development for the IMX174 has started. Simple streaming with fixed parameters is working. 3 new V2 prototypes are being built.

17.09.2019 Information on our EXTA side-project can be found on https://medium.com/@aschweiz/creating-an-exta-with-a-32x64-video-wall-led-panel-d72e0088c64f.

24.08.2019 Testing of the V2 prototype is ongoing. Aside from the integrated GPS antenna, everything is working as expected. IMX174 sensor boards are ready, the firmware update for these is currently being developed.

29.06.2019 A new firmware (0.2.15) and control tool are available on the downloads page. The new firmware adds a binary overlay in the last line of the image. The control tool is now able to parse the binary overlay and display it on the screen. It also includes the start time of each frame in SER videos and FITS files. The format of the overlay is documented on this page.

22.06.2019 Last thursday, the boards for the V2 prototype have arrived. One is already assembled and ready for first tests.

09.06.2019 The order for the V2 prototype PCB has been placed, the PCB should arrive in about 2 weeks. The order for the IMX 174 sensor board will be placed soon.

29.05.2019 Added an example to show the difference between 8-bit and 12-bit recording. Added firmware 0.2.12 and a corresponding version of the control tool on the software download page to support replacing the GPS time overlay with a black bar for dark frame recording.

18.05.2019 Software downloads are now available on this page. The re-write of the control tool is still ongoing. The control tool was initially programmed in C# / .NET and accessed the Media Foundation framework via COM interop, but we noticed frame losses at high frame rates and decided to re-implement the tool in C++ / MFC. Wish we had found this blog post earlier: https://blogs.msdn.microsoft.com/mediasdkstuff/2009/04/01/calling-the-format-sdk-directshow-media-foundation-or-the-wasapi-from-managed-code-c-vb-net/

09.04.2019 Serial #3 of the prototype v1 camera is ready to use.

08.04.2019 Firmware version 0.2.8 includes an option to display 4 digits for the fraction of the second (100 microsecond resolution); requires version 20190409 of the control tool.

04.03.2019 Support for writing FITS files (snapshots) has been implemented in the control tool. Writing ADV files is also working now, adding per-frame status metadata still needs to be implemented.

01.03.2019 The IMX428LLJ sensors have arrived!

01.03.2019 First ADV file generated from the control tool; some issues with brightness levels and an error at the end of the file.

Contact

If you have any questions or feedback for the project, feel free to send us a message (Messages button at the left side of the screen).