[How-To] Camera and lap timer setup for track use

[Oversteermybagel]

Hey everyone, I wanted to share what I do for camera setup and lap-timer setup for track in case anyone else is trying to sort out what can work. I posted video in another thread a couple days ago so you can see what sort of video quality I am getting there.

Mount​

For a mount I have a very simple headrest mount that I made out of a piece of wood. The idea here is that you drill holes in the wood such that the rails of the headrest are a near press fit into the wood and with enough length that the camera sits between the two front seats. I used a 15/32 bit as it was the largest bit my crappy drill could accept. This bit is quite undersized for the headrest rails. As you can see from the pictures below getting this fit to work required quite a bit of boring which had the benefit of getting the fit nearly exact after drilling. I can post measurements if needed but it is probably most accurate to measure yourself

Camera​

For camera setup I use a Go-Pro Hero 8 Black. This is not the latest model but it seems to work pretty well, these can be had for $280 used or $350 new. For camera setup I always record in 60fps and 2.7k with all stabilization off and with EV set to -2. I find that the built in camera stabilization has an aggressive pan effect that I really dislike so that is why I run without stabilization. Additionally the camera likes to expose the dash and blow out the road, -2 tends to deal with that nicely but if it is really overcast -1 is probably better. In order to do stabilization I use DaVinchi Resolve and use the 'Translation' algorithm with all the default settings -- I find this stabilization algorithm works really well for in-car footage. For storage I use a 128GB card and for battery I always pack a USB battery pack which can quick charge a go-pro

GPS Lap Timer​

I use my phone with an external GPS. For an external GPS I use a NEO-N9M radio paired with a HC05 bluetooth module. The N9M supports 25hz multi-GNSS (and I think maybe 40hz single GNSS?). I pair it with the HC05 (any $5 module will do) using a 57600 UART connection. I use a magnetic U.FL antenna which I stick to the roof of the car. Currently I am having some issues running the UART at 115200 that I would need to get the full 25hz so I am limited to about 14hz. The sparkfun module I linked is not cheap but for $65 it has a USB-C connection and a battery backup which is nice. It is possible to build a 10hz setup for about $25 using cheaper Neo-7n modules however almost none of these include battery backup so it will require another micro-controller to write configuration and without battery backup GPS lock will take quite a lot longer. My setup requires some configuration of the micros using by connecting to them over serial and sending them commands before they are ready for the first time use--after that they are plug and play (unless the backup battery ever runs out). I would recommend this setup and can give more details for anyone who has a linux system with a serial port (Raspberry pi or ortherwise) else, if you are not familiar with microcontrollers, it probably best to buy some commercial setup.