Is bluetooth wideband afr possible?

I hope to get wideband afr in racechrono, can bluetooth afr be connected to racechrono


  • edited May 2023
    That product is currently not supported, nor anything with same functionality.

    I'm willing to try it out if someone sends me it. Unfortunately I cannot send anything back, so it maybe a bit expensive with no guarantee that I can make it work.
  • I just tested a DIY device for getting AFR or Lambda into RaceChrono. It works along this route: Bosch LSU ADV (sensor) --> CJ125 (interface chip) --> STM32 (MCU) --> ESP01s (serial to wifi) --> RaceChrono DIY (RC3 via WiFi) on Android phone with RaceChrono v8.0.8.

    RC3 messages with Lambda values arrive at fixed 10 Hz rate to my phone -- I can view/record and confirm this in a WiFi terminal on the same phone. But: RaceChrono anyway reports an update rate varying between approx. 0.3 and 5 Hz -- and data frames are also missing in the data recorded by RaceChrono. I have the same problem on every phone -- tried 3 different Android phones.

    How to debug this problem?
    How to export and share the raw data as seen by RaceChrono?

    Below are some data lines from the WiFi terminal app (incl. the 10 Hz time stamps added by that app). Lambda value is 1.02 in the first line, followed by 19.4 and the LSU's temperature 769.9 degC.

    20:17:25.437 $RC3,,2979,0.000,0.000,0.000,0.000,0.000,0.000,1103.1,0,25.0,-273.1,50.0,40.0,127.8,0.0,1.02,19.4,769.9,11.60.000,0.000,0.000,0.000,0.000*0D
    20:17:25.538 $RC3,,2980,0.000,0.000,0.000,0.000,0.000,0.000,1633.5,0,25.0,-273.1,50.0,40.0,127.8,0.0,1.02,19.4,771.1,10.70.000,0.000,0.000,0.000,0.000*0A
    20:17:25.638 $RC3,,2981,0.000,0.000,0.000,0.000,0.000,0.000,3464.7,0,25.0,-273.1,50.0,40.0,127.8,0.0,1.02,19.4,770.4,11.20.000,0.000,0.000,0.000,0.000*0B
    20:17:25.737 $RC3,,2982,0.000,0.000,0.000,0.000,0.000,0.000,3464.7,0,25.0,-79.8,50.0,40.0,128.8,0.0,1.02,19.4,773.0,9.20.000,0.000,0.000,0.000,0.000*08

  • The number after the LSU Temp is not formatted correctly -- missing a comma: e.g. "11.60.000" should be "11.6,0.000".
  • @DrMotor I assume that fixed the issue? I cannot see anything else wrong at quick glance.
  • AOL: I think the format is OK, but I still have connection drop outs and/or lost frames while sending $RC3 via WiFi/TCP and simultaneously a RaceBox Mini via BLE.

    Maybe you can take a look at using RaceChrono as TCP server, as I mentionend here:

    "RaceChrono cannot yet (as far as I know) open a TCP port on the phone's WiFi Hotspot and act as a TCP server listening for connections to that TCP port. This could make DIY WiFi / TCP much easier to use. For example: An ESP01 could then be set up in "passthroug mode" and stream data at high speed."
  • @DrMotor Can you explain how this would help? The TCP handshake direction should not affect anything related to this issue, or at least I cannot see it right now.
  • The AT-firmware on ESP01 has two methods for sending data:

    1: text command AT+CIPSEND=xxxx, then wait 1 to 100 ms (or more) for the ESP01 to reply OK, before one can send xxxx bytes. The ESP01 will then again be busy and unavailable for new requests until all is transmitted.

    2. Let the ESP01 connect to a TCP port and enter "bidirectional passthrough mode". It will then pass all data until the magic string "+++". Advantage: much more efficient -- no more AT, OK, Busy/waiting. Drawback: It only works with that TCP handshake direction.
  • OK, the DIY protocols will hopefully be revised soon.
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