New datalogger for tractorpulling

General Custom Hardware / Electronics
1

Hello all,

We have a few questions about making a new device suitable for use with RealDash.

As a Tractorpulling team we are constantly looking for a way to improve our interface with the sensors on the tractor. This has lead to making our own in house made datalogger as existing solutions were not suitable for our needs. Currently we plan to use 44 different datavalues + GPS as a input data for RealDash. This number can grow in the future.

As we are in the final stages of designing our PCB, we want to make sure our device wil be capable of making use of the RealDash software. We will have 2 ways of interfacing with the device, Bluetooth 5.0 and RS232/RS485 (RS485 is preferred because we will be able to achieve higher data transfer speeds).

The questions we have are:

  1. Can RealDash make use of RS485 ports on windows?
  2. What is the maximum baudrate we can/should use?
  3. Does the baudrate we can use differ on RS232/RS485?
  4. Is there a RealDash solution for Raspberry pie devices?
  5. What is the data aquisition speed we can expect from RealDash (logs per second)
  6. What protocol is best for ensuring the highest possible performance of RealDash?
  7. Are there any other hardware design considerations to ensure high data aquisition speeds of RealDash?

Currently we are working on our 2nd hardware version of a datalogger, this version will have a highly capable MCU with loads of physical data input connections to meet our needs. For this version we are planning to use RealDash for our dashboard and maybe even datalogging needs. Datalogging will also be done on a SD card.

Thanks in advance for taking the time to awnser our questions.

Greetings,
Red Devil Tractorpulling

2

Welcome to the forums. Interesting project you have there!

  1. Yes. If you plug in your device to Windows and serial port appears onto Windows device manager, RealDash can use the port. The RS-type of the port is completely abstracted by Windows.

  2. You need to experiment with that. The Seeedstudio CAN adapter uses 2Mbaud and is read successfully by RealDash. We have not experimented with any faster baud rates.

  3. Not sure what you mean, you specify the baud rate in your datalogging device and use the same rate on RealDash.

  4. Not yet, but we just launched the My RealDash service which will allow us to build native Linux versions of RealDash.

  5. Depends, but achieving more than 1000 values per second should not be a problem.

  6. I’d recommend using RealDash CAN protocol with CAN FD (‘66’) frames for maximum output. See protocol specification here:
    RealDash-extras/RealDash-CAN at master · janimm/RealDash-extras · GitHub

  7. None what I can think of. Even the Arduino Nano is capable of pushing hundreds of values per second. Software design has an impact though. Try to minimize any blocking on code paths that send serial data.

3

Hello,

Thanks for your fast and detailed response.

I have some clarification for point:
3) Is the maximum achievable baudrate on RS232 different then on RS485, looking at your other awnsers, i assume the used interface has no influence (except their own respective interface limitations)

And a follow-up question for point:
5) Is 1000 values per second per sensor or 1000 values for al sensors combined.
Because we have a large amount of sensors this will greatly impact the amount of logs per second per sensor that we can achieve.

Greetings
Red Devil Tractorpulling

4

  1. This is completely abstracted by Windows serial port drivers, so there is no definitive maximum baud rate.

  2. Its values per second. If you read 10 sensors and achieve 1000 values per second, you get 100 updates per sensor per second.

The 1000 is not any sort of upper limit, just an example that could be achieved quite easily. We have had rate of 500000 values per second with RealDash CAN protocol using simulators on testing. But data transfer rate depends heavily on ‘everything’, thus I cant give you a definitive answer.

5

Thanks,

That there is no definitive awnser on the achievable data aquisition speed is ofcourse something we understand and something we are limited by with our old system. This is one of the reasons why we made the decision to make a new datalogger.

Atleast we can conclude that we will not be limitated by RealDash, it’s all dependent on how effective we can make the code in the datalogger that will present the data to RealDash.

If we have any further questions or something cool to share about our progress we will do that in this thread :smiley:

6

Yes, please share your project in ‘Project & Dashboard showcase’ section.