Dyno2 Dynamometer Software – setting up OBD interface

The software supports reading diagnostic data through vehicle OBD interface. It is possible to use wired USB interface or wireless Bluetooth interface. OBD system configuration is done in SETTINGS / OBD.

Dynamometer OBD interface setup

OBD tab contains:
(1) Interface settings
(2) OBD channels configuration
(3) Interface communication log
(4) Interface type selection: USB / Serial or Bluetooth
(5) USB / Serial interface port name – available ports are accessible with right mouse click
(6) Bluetooth interface name – available interfaces are accessible with right mouse click
(7) Communication logging option – useful for interface diagnostic – it should be disabled during normal operation
(8) Force reading all OBD PIDs option overrides configured read groups when checked
(9) Diagnostic information
(10) Diagnostic information log

Channel readout priority can be configured in Channels tab.

OBD channels for dyno software readout

Background color under channel defines it’s availability:

  • gray – availability is not confirmed yet or the vehicle didn’t advertise the channel as available
  • green – vehicle advertised channel as available or last read try was successful
  • red – last read try was unsuccessful

Amount of available OBD channels is high and interface readout frequency is limited. Typically interfaces can read 3 to 20 channels per second. Reading some 100 channels with 10Hz frequency would result in channel refresh once per 10 seconds, which is unacceptable for some channels.
This problem is solved with Read groups. Software has 9 read groups. Algorithm reads one channel at a time from a group then proceeds to next group. Empty groups are skipped. If we need one channel to be refreshed faster than others, it should be the only one in the group.
Let’s make example from configuration on above screenshot. We are interested in frequent readout of Engine speed (PID 12). It is assigned to group 1. Some other channels are assigned to group 2. Readout sequence follows:

  1. Group 1 : PID 12
  2. Group 2 : PID 5
  3. Group 1 : PID 12
  4. Group 2 : PID 14
  5. Group 1 : PID 12
  6. Group 2 : PID 15
  7. Group 1 : PID 12
  8. Group 2 : PID 5

As we can see, this configuration refresh engine speed every other readout. Other channels are refresh once per 6 readouts.
Readouts can be observed on timestamps in Last read column.

Whole communication with OBD interface can be observed in Communication tab if option Log communication is checked.

OBD communication preview in dynamometer software

USB interface connection procedure

  1. Select OBD interface type: USB / Serial
  2. Select USB / Serial interface port with mouse right click, i.e. ttyUSB0

Bluetooth interface connection procedure

Connect the interface to a vehicle and turn the ignition ON to supply power to the interface. Interface should be possibly close to the controller. Avoid any obstacles that can interfere with wireless connection.
Pair the interface in operating system. Click Bluetooth icon (1) and select Add Device… (2)

Wait for the interface to show up on the list. If the interface doesn’t show up it may be too far from the controller or it may be not powered.
Select the interface (1) and click Pair (2).

Enter PIN number. Typically 1234 or 0000. Click OK.

The system shows the following message:

The pairing is correct, just the plain operating system doesn’t know how to use the device. The dyno software knows what to do with it.
In dyno software select OBD interface type: Bluetooth
Select Bluetooth interface with right mouse click, i.e. AA:BB:CC:DD:EE:FF = V-LINK
Wait some time for the Bluetooth to complete connection procedure