User Interface

I decided I should post some of the UI and hopefully some video; this is after all, or should be, a very video and UI-heavy project. Work on the hardware side has left the software side behind.

So here is a screenshot of my current basic UI! Click for the full-size version.

The camera view is shown with EasyCapViewer (mac) or AmCap (Windows). Processing is used to create a basic control and indicator interface between the user and the serial port. 

Let's break down that UI a bit:

The camera is controlled by moving the mouse cursor within this grey box. The mouse position is mapped to degrees for the servos; left is as far as the pan servo will turn left, middle is straight forward, at the bottom is as far as the tilt servo can go down. This is not ideal as the mouse can go out of the box while you're watching the video, and you have no idea of absolute position; I often look down to see where the bonnet of the car is so I can tell where it's pointing!

The 4 squares at the top indicate the movement that should occur; basically they map the WASD keys to forward, back, left and right; they turn yellow when the relevant key is pressed. This was used for debugging.

Next the two V labels indicate voltages sent back by the arduino every second. Vcc is the inbuilt voltage meter of the arduino and Vcar is the voltage of the car battery, max 6V, which is input with a 1/3 voltage divider so that the arduino could even read 9V if I was running it at 3.3V. It cannot read a voltage above Vcc. There can be variation in these voltages near max capacity, but as it is currently well below that they are the same.

There is a text box which allows me to type any command to the arduino; currently it uses a simple string-based command system which is easy to debug but not the most efficient. It might be improved later but works for now.

Finally the ping time; yes, latency! It measures the round-trip time of a timestamped message to be sent, received and processed by the full stack, sent every second. One of the first things I implemented with the string-based command system was an echo response, so this sends a message of "ping <current-time>" where current-time is the number of ms since the program was started. When an echo is received, it compares the time in the message with the current time and there is your latency. The latency bounces between 33 and 66ms at the moment; I have another post to write about that. It does not measure lost packets, but if it has been over a second since it received a ping echo, it says "Ping timeout!!"

As for the video, well, it's not great, but I'm actually pretty impressed given the amount I paid for it all! There is some bands of interference near the top and bottom of the image; this is due to the wireless transmission. Bypassing the wireless makes the image clearer. But there should be a better wireless camera kit on the way.

So this is far from ideal. I want the video fullscreen, with the mouse free to move anywhere, I want the voltages and latency overlaid on the video like a HUD, and I want some graphics to indicate camera angle overlaid as well. There will be more overlays later too.

I met a new guy at Hackerspace who has experience with doing games and video programming and is interested in the project, which is great! He's a Windows guy, which is less great, but we'll figure it out :) So hopefully I will get some of this improved soon.