RaceChrono Hardware Datalogger - Ideas Please



  • Well i finally got my micro controller to talk to RC (had CR and LF in wrong order! idiot) and have sent my PCB design off to be manufactured so should have some logging hardware soon, if it all works I'll try and make it available one way or another
  • I didn't know there was a difference in the order of CR and LF still gets cursor to the beginning of the next line??? :-)
    What microcontroller is it based on Colin ?
  • Just realised one thing that would be really nice (if it has not been mentioned before), the ability to interface to ECUs (CAN, or cusom serial).
    I have litte knowledge about the specifics but know that one serial cable is easier to route then a number of new sensors.
    E.g. http://www.msextra.com/forums/viewtopic.php?f=101&t=38189

    Colin: Would it be possible to get hold of some working hardware from you at some time?
  • edited December 2010
    Hello all.

    I've also made a hardware datalogger:

    The project at first began being only an sdcard datalogger for megasquirt ecu. Then i added accelerometer and gps, then a couple of screens for what you want to display, then a friend showed me what racechrono can do and i fell in love.

    So i added a bluetooth module for the datalogger to send nmea data plus the chosen 6 engine variables to racechrono.

    This part is not finished as i havent received the new PCB's yet, but i think its working pretty well.

    Sorry for the bad english, and i hope you can help me to make it talk perfectly with RaceChrono as soon as i have a final hardware version.
  • hi all
    slash f1: yea i wouldn't have thought it would make a difference either but turns out it did, that was the problem, output looked perfect on screen but RC just wouldn't connect . I'm using a Motorola M68hc12 chip, bought it originally to make an ecu so already have RPM input sorted.

    NikLasFalk:CAN input from another ecu could happen, my board dosn't support CAN but there are some with the same micro (or similar) that do. i think the biggest limiting factor at the moment is the amount of RC inputs, any chance of getting a few more added in the next version?. with the accurate reference speed that the GPS signal produces i think one of the most useful sets of inputs would be individual wheel speeds as this would allow you to calculate very accurate longitudinal wheel slip, something that even very expensive data logging systems can't do. then adding 2 brake pressure sensors would make setting up brake bias almost to easy. my ultimate list of sensors would be
    1 x yaw rate
    1 x lat acceleration
    4 x damper position
    2 x brake pressure
    1 x steering wheel angle
    1 x RPM
    1 x Throttle position
    4 x wheel speed

    I just received my PCB back this week and they look good so should have a working unit soon, and like i said if i get it all working i'll try and make it available

  • I'm new to race chrono. I found this software and forum two days ago reading
    from the trackmaster forum!
    I'd like to thank aol and everyone for making this RC software available.
    RC has some features that are not available in other standalone DAQ systems.

    I've been pondering on building a hobbyist GPS race logger for a couple of years now,
    but the daunting software interface has always stopped me. RC seems to
    complement such a logger device very well.

    Anyways, here are some components for suggestion on the hardware side for a SPI microcon. Note that I'm not a hardware expert and have not built anything with these. But I've found these when researching for my racelogger project.
    - LTC2418 for ADC. It has 16 channels @ 24bit and SPI interface. the resolution can probably be truncated to 16bit or less.
    - LM2907/2917 as a "freq to voltage" converter. the examples on the datasheets show a variety of inputs for square wave and reluctor wheel sensors. tie these to the ADC, to save some microcon digital pins. The 2907 can also be a buffer to protect the microcon from a direct wheel sensor link.
    - MCP2515 CAN transceiver with SPI. I have no idea how this works.

    what is the max number of channels/sample rate that can reliably connect at a given serial baud rate, using the current $RC stream format and adding more <a#>?
  • After looking into this a bit more, the current $RC1 sentence has a maximum length of 109 characters long. On a 8, N, 1 serial stream, it will be 10-bits per character. So on a 57600 baud connection, the max sampling rate for the current $RC1 sentence is (5760/109) = ~52.8Hz.
    This assumes no GPS streams are injected into this. And also assuming signed 16-bit numbers (6 ASCII chars) on the data (not date, not some other fixed terms).

    For most uses, this is practical. There will be a direct correlation between data amount (number of channels) and throughput rate.
  • hi guys, just a quick update
    I've got everything working on the bench, 8 x 0-5v AtD, 8 x Timers (RPM or wheel speed) and 4 switch inputs. It's all boxed up and ready to go in the car, my next event is at the start of march so should have some real results by then
  • Hi,

    What "triggers" the datalogger in RaceChrono?

    One time, and only one time, I started a session and was able to see "DataLogger Time", "rpm", "analog1", "analog2", etc. when I toggle through the display.

    Normally, I can only toggle through Satellites, GPSTime, Speed, Altitude, etc.



    Also: here's an example of the output RaceChrono is getting via bluetooth:





  • colin - have you any plans to make these available to others? Subject to price, I can see it being very popular. I, for one, would like more inputs than my current data logger provides. I've moved away from RaceChrono over the winter as I need more than GPS and I don't have enough electronic knowledge to do the clever things people have mentioned in this thread. I can hold a soldering iron and that's about it! I'm now using a dedicated data logger that has built-in GPS, accelerometers and RPM all hooked up to a dashboard that shows me useful info such as RPM, gear, shift lights and split times.
  • aolaol
    edited February 2011
    Kelberth: When ever there is data from data logger, you should be able to see the extra channels. The data from your copy/paste seems invalid, see the *AA checksum on every line.
  • edited March 2011
    been a while since we've been here on the board, but I wanted to post our 'update'- and it's really cool that so many have been able to make their own micro to take data.

    aol- that should be a strong message to tell you how great your software is.

    So, where we are now is a current list of stuff-

    From Parallax
    Propeller Micro, proto board w/USB-
    simple 8 channale a/d
    SD card adaptor
    and box

    From Sparkfun
    venus GPS + SMA antenna
    integrated 3 axis accelerometer + 2 axis gyro.

    That will give us GPS + the 5 dynamic channels + 3 analogs + RPM- which is what I require for my vintage Alfa. The last software update I have is capable of all of that. But we do think that it will be easy to add a second multi channel A/D for anything that we will have to put in various order to make sense with. But we'll have to appeal to aol to make the RC more flexible... I need to make a donation before I listened to in that respect....

    Anyway- it was asked a few times why we chose the propeller board and not a few others. Well, it may be 50% more expensive than others, but that's $10 out of $200 (US), but the reason is that the main developer is familiar with coding the Propeller. And an added benefit is that the parallax library includes code to effectively use the gyro data- where we change the deg/sec data into an orientation angle. Much better to use. But IMHO, any micro will work as long as it inputs the information correctly, and then outputs it in a format that RC or any other program can use.

    We need to work out a few details on this before buying, and I hope to make a web page explaining this, some. But it's pretty cool.

    The intention is that it's similar to MS, that you make it yourself.

  • BTW, sorry about the long paragraph. Not sure how to avoid that- it looked good typing.

    maybe I need to format as text?
  • alfadriver: Yep, use format as text. About making RC more flexible, maybe while developing the Android version I will be able to make some changes to the internals. But be warned that the first Android version will be very basic features, and the additional stuff like data loggers etc will come a bit later.
  • edited March 2011

    - RaceChrono compatible
    - BlueTooth connectivity (mobilephone/PC/laptop)
    - Main power 12V
    - Size 22*55*90 mm
    - 5V (100mA) output for external sensors
    - 8 analog inputs (each channel configurable: 0-5V / 0-15V)
    - 2 digital inputs (configurable: pulsecounter / periodcounter)
    - configurable sample rate 20 Hz / 100 Hz for each analog channel
    - configurable compensation curves for each analog channel
    - configurable multiplier/divider/offset for each channel
    - standard pin-connector for software flashing (for those who want to develop their own sw)
    [- standard pin-connector for possible memory card module in future]

    More info:
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