Rate issue with OBDLINK LX on Android

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tomprout
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Rate issue with OBDLINK LX on Android

Post by tomprout »

Hello I am getting poor result when using the recommended OBDLINK LX dongle.

I was able to have a 15Hz rate once but most of the time I get a rate of 3-4 Hz.
Sending the log file to you Harry...
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Harry
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Re: Rate issue with OBDLINK LX on Android

Post by Harry »

Hi,

From the log you've sent I think it is some load issue - either on the processing side (smartphone), or Bluetooth bandwidth. Have a look into the log analysis below. Variance by PID: TPS 60-280ms, VSS 30-160ms, RPM 50-290ms. To achieve 15 Hz (which would be a lot for Android), an average reply time of 15ms is required. A typical value for a CAN based car is 8 Hz which means approximately 36 PID/s or 30ms reply times.

Please make sure you have no apps running in background doing processing and requiring processing time. More important, disable any disturbing Bluetooth devices in your car - car stereo in particular. You can find disturbing Bluetooth sources using the Android Settings app / Bluetooth.

- Harry

Code: Select all

09066359460 +   10ms ---------  mode: 1 pid: 0x11 [TPS] (index: 29)
09066359460          Tx: "30 31 31 31 20 31 0D '0111 1\r'"
09066359520 +   60ms Rx: "34 31 31 31 32 38 0D 0D 3E '411128\r\r>'" (9)
09066359520          ---------  mode: 1 pid: 0x0D [VSS] (index: 31)
09066359520          Tx: "30 31 30 44 20 31 0D '010D 1\r'"
09066359550 +   30ms Rx: "34 31 30 44 30 30 0D 0D 3E '410D00\r\r>'" (9)
09066359600 +   50ms ---------  mode: 1 pid: 0x0C [RPM] (index: 28)
09066359600          Tx: "30 31 30 43 20 31 0D '010C 1\r'"
09066359650 +   50ms Rx: "34 31 30 43 30 42 42 38 0D 0D 3E '410C0BB8\r\r>'" (11)
09066359660 +   10ms ---------  mode: 1 pid: 0x11 [TPS] (index: 29)
09066359660          Tx: "30 31 31 31 20 31 0D '0111 1\r'"
09066359740 +   80ms Rx: "34 31 31 31 32 38 0D 0D 3E '411128\r\r>'" (9)
09066359740          ---------  mode: 1 pid: 0x0D [VSS] (index: 31)
09066359740          Tx: "30 31 30 44 20 31 0D '010D 1\r'"
09066359890 +  150ms Rx: "34 31 30 44 30 30 0D 0D 3E '410D00\r\r>'" (9)
09066359960 +   70ms ---------  mode: 1 pid: 0x0C [RPM] (index: 28)
09066359960          Tx: "30 31 30 43 20 31 0D '010C 1\r'"
09066360250 +  290ms Rx: "34 31 30 43 30 42 43 43 0D 0D 3E '410C0BCC\r\r>'" (11)
09066360250          ---------  mode: 1 pid: 0x11 [TPS] (index: 29)
09066360250          Tx: "30 31 31 31 20 31 0D '0111 1\r'"
09066360350 +  100ms Rx: "34 31 31 31 32 38 0D 0D 3E '411128\r\r>'" (9)
09066360350          ---------  mode: 1 pid: 0x0D [VSS] (index: 31)
09066360360 +   10ms Tx: "30 31 30 44 20 31 0D '010D 1\r'"
09066360520 +  160ms Rx: "34 31 30 44 30 30 0D 0D 3E '410D00\r\r>'" (9)
09066360640 +  120ms ---------  mode: 1 pid: 0x0C [RPM] (index: 28)
09066360640          Tx: "30 31 30 43 20 31 0D '010C 1\r'"
09066360830 +  190ms Rx: "34 31 30 43 30 42 39 43 0D 0D 3E '410C0B9C\r\r>'" (11)
09066360840 +   10ms ---------  mode: 1 pid: 0x11 [TPS] (index: 29)
09066360840          Tx: "30 31 31 31 20 31 0D '0111 1\r'"
09066361120 +  280ms Rx: "34 31 31 31 32 38 0D 0D 3E '411128\r\r>'" (9)
09066361120          ---------  mode: 1 pid: 0x0D [VSS] (index: 31)
09066361130 +   10ms Tx: "30 31 30 44 20 31 0D '010D 1\r'"
09066361170 +   40ms Rx: "34 31 30 44 30 30 0D 0D 3E '410D00\r\r>'" (9)
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tomprout
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Re: Rate issue with OBDLINK LX on Android

Post by tomprout »

Which information do I need to check?

Because when looking at the sensors list I get a rate of 4 Hz but when I look at the engine page I get a rate of 4hz and a pid rate close to 15.
Is it good values?
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Harry
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Re: Rate issue with OBDLINK LX on Android

Post by Harry »

A typical value for a CAN based car is 8 Hz which means approximately 36 PID/s or 30ms reply times.
So for a CAN based car the value is lower than expected.

- Harry
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