Technical What features should a data logger have? I'm designing one and I want your input!

[odavidson]

Hello petrol heads!

I am an engineer with a keen interest in motorsports, I've been working on a new datalogger specifically designed for go karts and racing. The aim is to create a powerful and user friendly tool that helps you all shave even more time off each lap!

One key feature I want is to be able to sync video to virtual dials that can be overlaid on a video, speed/G force etc. I think this would be a great way to see the difference between a good lap and a bad lap, and put numbers to improvement. Plus when I'm riding dirt bikes off road, I want an indication to the viewer that the reason I'm struggling is the slope is 45 degrees! Video is terrible for showing that kind of thing.

However, I don't want to build this datalogger in isolation. I believe that the best ideas come from the community that will be using the product. That's why I'm here, seeking your valuable insights, feedback, and ideas to make this datalogger the best it can be.

I've been thinking that it would be best to split the features and sensors into core/deluxe/pro products, so you get the features you want at the best value. The datalogger will be expandable, so you can add sensors/modules as needed later, without buying the whole thing again. But it would be cheaper to have more inputs on the data logger rather than buying a new sensor module, but if there are unused features, you're paying for something you're not using. So I'm trying to split features up, here's where I am at the moment:

Core features:
- 25Hz GPS
- 9 axis accelerometer/gyroscope/compass
- RPM input
- Coolant temperature
- Sensor bus: more sensors and a display can be easily added
- SD card storage

Deluxe:
- Core features plus:
- Exhaust temperature input
- 4 analogue inputs for things such as: throttle position, brake position, engine oil temperature, brake caliper temperature, brake pressure etc

Pro:
- Deluxe plus:
- Another 4 analogue inputs
- Waterproof enclosure with waterproof connectors
- Infrared lap timing, competition systems

From people I've talked to, waterproofing isn't that much of an issue for go kart dataloggers. If electronics are used outside without protection, even just the water in the air will cause electronics to corrode and fail over time. Waterproofing does add a lot of cost however. Both ends of a typical waterproof connector (panel and cable mount) can add up to around £20, plus time soldering wires to the connectors, waterproof enclosure etc. It could easily add £100 or more to the sale cost of the datalogger. The biggest advantage to not being waterproof is there can be a slot for the SD card, without expensive waterproof doors or external SD card adapters plugged into a waterproof connector. What do you guys think about waterproofing? Would it be worth it to you? I think any electronics that is to be used outdoors should be well waterproofed, based on the electronics I've seen corrode in my career.

What features would you consider essential for each model, and what optional features would you like to have as add-ons to keep the core model affordable while allowing for future expansion?

Your insights will be the driving force behind this project, and I truly appreciate any suggestions, ideas, or questions you may have.

Feel free to drop your thoughts below, and let's create something remarkable together!

Oscar

Youtube videos for those interested!
Go karting at team sport:

Off roading with bikes: https://youtube.com/@offthebeatenbike6045

 

[mandelbug]

OK, waterproofing is a must. Yesterday was testament to that!

Look at Race Render for the overlay software. It accepts input from Mychron/Alfano/UniPro. These are the data loggers to look at.

You'll need GPS for lines, input for temperature (water/cylinder head), RPM, speed (can be GPS based, will cover most), lap times (again GPS).

Then you need to consider the track database, the big three already have the tracks 'programmed' in to them.

 

[odavidson]

Thank you very much for the reply!

Just had a quick look at Race Render, looks interesting. I'll see if I can make the data compatible with that. I've been looking at writing my own software for the overlays, and providing it free with the datalogger. I think I can improve over Race Render, but that will take time.

So far for inputs I've got:
- GPS
- Accelerometer/gyro/compass
- RPM input
- Speed input
- At least two temperature inputs, possibly exhaust temperature

I think you're right, waterproof is a must! How else do you jet wash your kart anyway? for getting the data off with a waterproof case, I see two options: download to PC over USB, or (better) download to an external SD card in a holder with connector you plug into the datalogger at the end of the day. Would still need power present to download. What do you think about this? Would you prefer USB or a customer plug in SD card adapter?

Track databases is something I need to look into. Thank you very much for all the feedback!

 

[Waspq]

Hello,
looks really intersting what you are tryring to build. I acutally looked into bulding something for myself.
First of all a high accuracy (relative accuracy is more important the absolute accuracy in my optinion). What revicer do you plan to use?
I would really like to see a 9 dof IMU like you mentioned.
Must have inputs:
-RPM
-Water temp
-Exhaust temp (type k or probably type n sensor)
-Speed sensor for accurate speed reading and calculate distance

I also think waterproof is a must.

Download via wifi/bluetooth is nice to have. But download via usb cable is also good for me.
Dont like the idea of a SD card.

What do you think about using for a data analysis tool? motec? Or build something from scratch?

Would be nice if you can share some of your progress here. I‘m really intrested in something new for karting!

 

[odavidson]

Hi Waspq, thank you very much for the reply!

The GPS receiver I'm planning to use at the moment is the Neo 8M. It looks like the most sensitive/accurate 25Hz GPS easily available. I'm planning to have an external active patch antenna, and a waterproof SMA connector. There will be a sensor bus, so a different GPS could be used. What kind of GPS implementation would you like to see?

Yes 9dof IMU would be great, with the right data fusion it would make the GPS much more accurate.

Glad you agree with waterproofing. Yes I think it's a must. I've been looking at connectors, and I think using 4 way connectors is best, they seem the most available.

At the moment I think connectors will be:
Power (plus log enable switch and LED - used for video sync)
Sensor bus (additional sensors, display, telemetry radio link etc)
Digital inputs (RPM and speed - isolated)
Analog (2 ADC inputs, possibly either thermocouple (software selectable type) or thermistors (PT100/PT1000)).

Bluetooth/WiFi is an option. I've worked with a few WiFi/Bluetooth chips before, that could be a low cost route. It does mean I would have to get it RF certified. I've taken WiFi/Bluetooth through RF/EMC, it's very expensive not impossible, but I'd rather start with a wired solution. Would be very convinient with Bluetooth to your phone, then to google drive/PC.

For analysis, I'd start by making the data easily available (CSV) and use external tools, but I do want to write a custom program for showing the stats, with a timeline and the video synced, ideally multiple video sources! After the hardware and firmware are done, I'd probably focus on creating the overlay software for video, then analysis software for viewing all data, comparing other laps etc. Does that seem like a good approach?

I'll post in here with updates! Currently I'm working on choosing an enclosure, connectors, PCB size etc. Then I'll lay out the PCB and build some prototypes. I'll make a start on the firmware while PCBs are on the way. In the mean time I've been making a start on the GPS data/message processing!