I am starting a new project which aims to take a live stream from a DSLR type camera (HDMI), and overlay a visual proximity warning system over it. Ideally, i would then like to output this over either an analogue or digital data link.

I was going to use RPLIDAR, a cheap lightweight 360 degree laser scanner to obtain distance information for objects around my octi-rotor. I was then planning to use this information in order to give me a visual warning when i am getting too close to an object. The warning would come in the form of a border overlay on my video feed. 

This border around the OSD would be split up into 8 sections, the colour of each section changing as objects get closer to my multi-rotor. (e.g. green(d>5m), orange (3m<d<5m), or red (d<3m)). For example, an object 2m away to the aircraft's right hand side would cause the right hand side of the OSD border to turn red. An object 4m away in front of me would cause the top section of the border on the OSD to appear orange. Etc...

I will need to decode the LIDAR data (USB -UART), and then produce the border image from these measurements. In terms of the video streaming and overlay, i have read a fair bit on Gstreamer which would seem to do what i need. Am i correct in my thinking?

I was looking into different hardware setups, and thought that this could be a good project for the Raspberry Pi however im not sure the Pi could take in digital video from cameras (HDMI)? Also, not sure if the processor is going to be able to handle this kind of task?

I would be really grateful for some advice regarding the best HW and SW setup for this kind of project. I don't mind hard work, but want to make sure i set off in the right direction at the start!

I will jkeep you all in the loop regarding my progress

Thanks in advance


You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –


  • This might not help you directly but we've been looking at anti-collision LIDAR for several years and have a commercial system working with a range of 100m. This runs on a Linux box and can handle complex shaped alarm zones - so the alarm distances might depend on the air speed and the direction of travel. Unfortunately, this system is not available to the public as it is part of an OEM product and there are contractual restrictions.

    However, we are considering adding high speed (1000 rps), long range (>100m) capability to one of our small laser modules, the SF10/C. Whilst this wouldn't be a complete scanning LIDAR on its own, it would be straightforward to mount it onto a rotating platform or servo to make a narrow or wide angle scanner.

    The reason why we want such long range is that once the UAV is at full speed, there is a significant reaction time to obstacles. During the slowing down process, the 'copter tilts backwards and may lose sight of the obstacle. Having sufficient warning time helps to keep evasive maneuvers more gentle, and may only necessitate a minor course change instead of an emergency stop.

    In addition to the long range sensors, we are also developing multi-beam devices that could help to keep obstacles in view whilst the 'copter is tilted backwards or forwards during deceleration and acceleration.

    Like I said, this might not be directly relevant to your project but thought I'd post the info anyway :).

This reply was deleted.