It seems like ages since I last wrote a blog post but the summer term is always a crazy time at school with revision, exams and the summer show.
This year we performed High School Musical at school, and following the tradition of previous shows I wanted to use a Raspberry Pi as part of the theatre tech.
One of the difficulties of staging shows in our theatre are where to place the band and the musical director. We decided to put the band and MD at the back of the stage in front of our cyclorama. Whilst this sounded very good we found that the cast were missing cues from the MD as they couldn’t see him. I was tasked with finding a solution to this problem. After looking at various solutions involving hiring camera systems or using video cameras I decided that I would go for a low-cost Raspberry Pi based solution.
The core of the project is the motion eye home security Pi software.
Installing the SD card is simple (make sure you have the right version for your Pi!) and the front end is very easy to navigate. There are essentially three ways you can view the images:
– locally on a monitor attached to the Pi
– network connection
– wifi connection
The Pi will need to make a network connection for motion eyes to work.
To make the Pi more robust I found two cases on thingiverse and 3D printed them to make a traditional style camera.
Testing the camera in my classroom was fun when my class walked in to see monitors all around the room displaying the same video feed they couldn’t work out how I was doing it.
We did notice a very small amount of lag on the streamed video signal which I decided would be good enough for me to have up in the control room but wouldn’t be good enough for the ‘live’ feed at the front of the stage. To improve the lag time I ended up buying a relatively cheap HDMI splitter which handily was powered by a 5V usb cable straight from the Pi. Using approximately 30m of HDMI cable I ran the video feed to the front of the stage. Additional monitors were connected to the splitter on stage for the musicians.
Pi camera at the back of the stage
Live video (over HDMI)
This camera based system will now be a permanent fixture of all shows we now do. Ideally I will make the cabling permanent and mount the camera somewhere suitable.
The finished rig consists of:
- Raspberry Pi 3 with camera in 3D printed case
- HDMI splitter (http://amzn.to/2v39aAz £13.99)
- (Old) wifi router
- (Old) TV for front of stage
- monitors on stage
- Laptops / tablets / phones etc to view video feed from around the stage
For a relatively cheap build I was really pleased with the final project. The Raspberry Pi camera worked perfectly for the rehearsals and shows. I was asked many times by people how I was able to get the video to the front of the stage and to the control room. This gave me many good opportunities to talk to people about the Raspberry Pi too!
If I had more time ….
We made quite a bit of use of cheap (and I mean cheap) LED strips to mark the outline shape of part of the basketball court. If I had more time I would have used a Pi to control them. Next year we are probably doing Return to the Forbidden planet and I think the Pi will definitely feature in that!