G’day all. I very basic learning raspberry pi guy here. I have hooked up a raspberry pi 4b with multiple display screens into my car and am now looking at more options to play with. I would like to have a GPS speedo, with it’s own separate display that also sends data to the 4b.
My ultimate goal is to run some form of code that prompts different (pre-selected) images and sounds when the vehicle achieves certain speeds.
I have watch a few different tutorials where people have made GPS speedometers and am keen to start but I would welcome some input into the easiest hardware units to purchase.
Thank you in advance for any ideas you may have and links that may help me in this quest.
What programming languages are you familiar with (or learning)?
GPS modules usually come package with libraries/modules that help interface with the device and we could recommend one with support for your preferred language.
Also consider if you need an “external” antenna for the GPS…
e.g. Assuming the display is inside your car, the GPS receiver may have issues in getting and keeping a good lock if located in the same location. The better the lock (more satellites spread over more of the sky) the more accurate your reading is likely to be.
So to get the best results you may need to place the GPS “antenna” in a different location.
What I mean by “antenna” is either a smaller module with loger comms lead (external to your display housing); or an actual separate GPS and Antenna.
If you use an real external antenna then you will need to keep the coax lead length as short as you can and/or may need to use an active antenna (i.e. it gets power to amplify the signal).
Some of this could be a bit of trial and error to get the best result. and time to first lock can be slow. For a play, I would get one of the cheaper units (I lock the NEO-6M as it works well for most of my projects and a good price), then see how that works in different locations in your car.
@ahsrab292840 I like the USB/TTL Raspberry Pi GPS Tracker idea. and then getting an external antenna as suggested by @Michael99645 / GPS/GNSS Magnetic Mount Antenna SMA - 3m.
@Pixmusix The only coding I have done (learned) was based on wiki data to get the screens talking. I am running 2 Wave-share separate screens. 1 is a 7inch square type and the other is an 85mm which sits in my instrument cluster (connected to a pi4B)
I used this as a base starting point with lots of ideas in mind but not much knowledge.
So I guess I am looking to learn the most appropriate code from a start point based on research and of course forum suggestions. Do you think the combo I have mapped out here is a good place to start?
Another way that looked interesting was using a ESP32 Development Board WT32-SC01 Plus with 3.5in 320 * 480 Based on ESP32-WROVER-B Multi-Touch LCD Screen. This has bluetooth capability so I am thinking build a standalone module but then run a bluetooth link to the Pi.
Big ideas but probably filled with coding nightmares.
Its all going in a 1974 Datsun so no matter what I do, even if basic is way cool
If you don’t have much experience with coding, it’s probably better to go the Python / Micropython route. It is a much better learning curve than any other coding language.
My big worry with you using the ESP32 Development Board, however, is just that while Micropython can be used with it, its nowhere near as well supported as C++ is on the Arduino. I’m sure you could hack something together though, it might just be a bit more complicated.
My other concern would be just being careful with using the Bluetooth on the Pi 4. The Pi’s antenna is quite small and interference is common. My Bluetooth Keyboard started missing every fifth keystroke from my Pi and it works fine with all my other devices.
