BOS1901-Kit Support FAQ

  1. BOS1901-Kit does not respond when plugged in, no LED turns on.
  2. When playing a waveform using Audacity®, measured voltage waveform shows fade-in effect.
  3. When playing a waveform using Audacity®, waveform is not played on the BOS1901-Kit one time out of two, and the other time the waveform is played twice.
  4. When trying to play a waveform using Audacity® BOS1901-Kit board fails to playback the waveform and gets stuck with the red LED on.
  5. When I plug a BOS1901-Kit on a USB port, other boards already connected are triggered (red LED turns on).
  6. The piezoelectric actuator seems to be driven even when playing a null waveform (consisting of only zeros).
  7. How should I experiment the out-of-the-box sensing and feedback feature of the BOS1901-Kit?

BOS1901-Kit does not respond when plugged in, no LED turns on.

Date Added: 2018-11-23

Check connection between the BOS1901-Kit and USB port. Try another USB cable. Verify if the Cypress Speaker driver is properly installed and enabled.

When playing a waveform using Audacity®, measured voltage waveform shows fade-in effect.

Date Added: 2018-11-23

The version 2.3.0 of Audacity® applies an automatic fade in effect at playback even though the generated tone looks normal on the screen. There is currently no option of deactivate this feature. Until this feature can be deactivated in a subsequent version of Audacity®, please use version 2.2.2 or earlier to drive the BOS1901-Kit.

When playing a waveform using Audacity®, waveform is not played on the BOS1901-Kit one time out of two, and the other time the waveform is played twice.

Date Added: 2018-11-23

Selecting the MME driver results is every other playback not being played and the other being played twice. To solve this, select Window DirectSound driver in Audacity®.

When trying to play a waveform using Audacity® BOS1901-Kit board fails to playback the waveform and gets stuck with the red LED on.

Date Added: 2018-11-23

This situation may occur when the project sampling rate in Audacity® does not match the waveform sampling rate. When this happens, a manual reset using RST button the board is required.

Since the development board firmware is sampling the BOS1901 ICs at 8kHz, we recommend you generate 8kHz wave files and make sure to sample your Audacity® project at 8kHz.

When I plug a BOS1901-Kit on a USB port, other boards already connected are triggered (red LED turns on).

Date Added: 2018-11-23

This may occur if one BOS1901-Kit already plugged is used by the Operating System (Windows) as the main output device (speaker). When the other BOS1901-Kit is plugged, Windows is playing a wave sound on the speaker (BOS1901-Kit) thereby driving a piezo actuator and turning the red LED ON.

Make sure Windows is not using any BOS1901-Kit as its main speaker to avoid triggering playback on the boards every time Windows plays a sound.

The piezoelectric actuator seems to be driven even when playing a null waveform (consisting of only zeros).

Date Added: 2018-11-23

This occurs when DIP Switch 1 is set to OFF. The selected voltage range is -10V to 60V. In this range, voltage gain is 35V and offset is 25V. When playing waveform values of 0, the BOS1901-Kit will force 25V on the BOS1901 output, thereby producing a voltage step from 0 to 25V on the piezo actuator which can be felt as the actuator being triggered.

This gives the impression that a wave or pulse is played on the actuator while it is in fact a matter of playing the appropriate value.

Note that even when applying appropriate negative value so the BOS1901 output is driven to 0V, Audacity® adds 0 values before starting the wave, therefore a 0-25V square pulse is still played on the piezo actuator. To be sure no 25V step occurs, you can select the ±95V symmetrical range by setting DIP Switch 1 to OFF. However, using a TDK PowerHap 2.5G, be sure to limit the waveform so no voltage higher than 60V is produced, and avoid triggering the sensing and feedback (this would playback a 95V pulse on the piezo actuator, likely damaging it).

How should I experiment the out-of-the-box sensing and feedback feature of the BOS1901-Kit?

Date Added: 2018-11-23

Here is a detailed procedure to experiencing the BOS1901-Kit sensing and feedback feature:

  1. Start with all DIP Switches set to OFF (out-of-the-box configuration).
  2. Make sure to connect the TDK PowerHap 2.5G piezo actuator on channel A when first using the kit (red wire on HV+ and black wire on HV-).
  3. Plug the USB connector, and wait for the green LED to be ON and the red LED to be OFF (this will take about 10 seconds).
  4. Then you can push on the piezo actuator just as if it was a button. You will feel a click.
  5. With switches 5, 6 and 7 all set to OFF this “click” might be too subtle.
  6. Turn all switches 5, 6 and 7 to ON and then push the piezo again; the feeling should be clearer and stronger, and require less pressure to trigger.
  7. You can then try various setting combinations for switches 5 to 7 to see how it affects the feedback.
  8. If all the above goes well, then plug the piezo to channel B, and set SW3 to ON and SW4 to ON.
  9. As you gradually apply pressure on the piezo, you will feel 3 events: 1 click, another click a bit stronger, and then a buzz. If you have trouble distinguishing all 3 events, set SW7 OFF to decrease the sensitivity.