DRIVE-2 Instructions for Use with Birch

1. Connect the DRIVE-2 optics to the Birch interface unit

There is a shiny optical bundle permanently attached to the DRIVE-2 assembly. Normally, this should be connected to a long extension bundle (BE-17m or similar), and then that bundle should be connected to the Birch interface unit. A normally functioning DRIVE-2 will always work with this two-part optical connection. In some cases DRIVE-2 will also work when connected directly to the Birch interface unit, but this is not guaranteed, because with some devices the optical signals are too strong to work correctly with the direct connection. So, at least for first tests, please use the two-part connection.

2. Turn on the Birch interface unit

Connect the power supply: Note that there is a flat side on the power connector and this should face towards the front panel touch screen. The connector should click into place.

Push in the black button to the left of the power supply connection to turn it on.

It will take about 30 seconds for the device to be ready to use.

3. Choose the mode and do basic tests

Tap on the 'hand' image to choose the response device and then choose 'Automatically': after a few seconds you should see "We detected DRIVE-2. Is that right?" -- Tap Yes to confirm. If Birch does not automatically detect the DRIVE-2 device it may mean there is an optical problem, so in that case please check the optical connections from step 1.

Now that the device has been selected, choose an output mode by tapping on the lower left button. Do this with the pedals at rest (feet off!) and the steering wheel centered. There is only one mode option at this time for DRIVE-2 ("HID_DRIVE_JOY" - an HID joystick output mode), so select that one.

A popup will show "Please leave the steering wheel centered for a moment" -- when that goes away give the steering wheel a few quick turns left and right to show the interface unit what range of signals to expect. (The steering position is detected using a reflective quadrature shaft encoder. So what the interface unit "sees" are alternating reflective and non-reflective bands. When you turn the steering wheel back and forth the interface unit adjusts the gain on its inputs to set the alternating bands to good working levels. There is a third "index" channel which is reflective when the wheel is very near zero and non-reflective at all other positions.)

Now check these 5 'vitals':

1. the small vertical bar in the square display is centered when the wheel is centered,
2. that it moves to the right when the wheel is turned clockwise, and vice versa,
3. that the small dot in that display moves up when pressing the gas pedal, and to the left when pressing the brake
4. when the button is pressed the 'Thumb' indicator should be activated
5. when the wheel is turned away from the centered position the 'Index' indicator should light up

If any of these 5 are not quite right please see Troubleshooting.

4. Connect the USB cable and check with software

The 5 'vitals' above are only checked qualitatively using the Birch display indicators. To check them numerically use your software.

5. Connect the analog output cable to check electronically

Check the signals against the preliminary specifications in Drive2AnalogCable.

Troubleshooting

Detection of the gains for the steering wheel shaft encoder occasionally fails. This seems to be related to the speed of turning of turning the wheel and, specifically, seems more likely to happen if the wheel is turned very slowly. Turning it about 1/4 turn CW and CCW, at about a 1 second period, seems like a reliable approach. So, if the steering wheel indicator is not behaving as described above, please quit the operating mode (by tapping on the DRIVE-2 image, and selecting the 3rd option "None: choose to pause response collection") and then re-select the device and the operating mode.

If the steering wheel behavior is not resolved after this, restart the Birch interface.

If the other channels (gas, brake, button, or index) are not working it probably indicates that one of these was the case during the calibration:

• the pedals were not at rest,
• the button was being pressed,
• the steering wheel was not centered