Is there any way to connect a Raspberry Pi 3 wirelessly to a monitor? I am building a (caterpillar)tracked robot and want to develop code and test stuff out without needing the HDMI cable to be plugged in.
If you just want to control the pi wirelessly, the easy answer, if you can work a command-line, is to enable the pi for wifi (newer versions using the 'stretch' image require a blank 'ssh' file under /boot). Then you can ssh to the pi from another machine, mac or win, using 'ssh pi@ip_address'. If what you really want is to have your robot 'see' and throw the image it sees as it's driving around, I recommend getting a PiCamera (around $30) which hooks up to the board. Then check out this blog to live-stream the video from the camera: https://www.digikey.com/en/maker/blogs/streaming-live-to-youtube-and-facebook-using-raspberry-pi-camera/969a7932d47d42a79ba72c81da4d9b66
I would look down the avenue of screencasting. It would likely mean that you'd need to initially set it up on the Pi with traditional HDMI temporarily. The following thread discusses some areas to look into. But I'm sure there is some Google Chromecast set up you put together.