Sound task with HARP, Bonsai and ONIX

[BaptiAllain]

Hi HARP community,

I am setting up a hardware with the aim of doing ephys recordings in awake and head-fixed mice during sound stimulation, as well as optogenetic stimulation.
The ephys acquisition is done through the ONIX system of OpenEphys, going onto the ONIX breakout board.
The light delivery is controlled through the Cyclops LED Driver from OpenEphys.
The sound stimulation is done through HARP sound card & amplifier.

I'ld like to play 2 sounds (A & B) with different probabilities N times. The original idea was to trigger light with one of these 2 sounds through a wire connecting the HARP sound card with Cyclops, and to receive the timestamps of each sound delivery through wires connected to the breakout board (see the schematic below), with the aim of controlling everything through Bonsai.

I have seen on a discussion on the bonsai discord (support channel) that as it stands now with the HARP sound card, it is not possible to play a sound N times (https://discord.com/channels/722881880122327101/727928858757562430/1410783817274359940), and that driving the sound card through bonsai induces high variability in sound delivery. Given that rhythmicity is important in our task, Ceci from OpenEphys team kindly suggested that I could trigger the sound board with an external device, programmed with the desired timing frequency pattern.

Few questions:

• Does this option of triggering the sound board with an external device seems the more efficient solution to you?
• Would a Teensy LC (https://www.pjrc.com/teensy/teensyLC.html) be powerful enough as an external device?
• Would the best be to get the timestamps (and light triggering) out from the Teensy or from the sound board still?

Thank you very much for you help.

Best,

Baptiste

[banchan86]

Hi @BaptiAllain!

1. Yes, the external device seems the most efficient solution, for now.

2. Hmm, there have been a few reported problems with Teensy microcontrollers (for example). I am not sure how compatible that Teensy microcontroller is.

   • One option would be to grab an older Arduino (like an Arduino Uno R3) for the best compatibility.
   • Otherwise you might want to consider the Harp Hobgoblin, it's a low-cost Harp microcontroller built off a Raspberry Pi Pico/Pico2. There is a PulseTrain register that can generate a N number of pulses, and it has the added advantage of being in the Harp ecosystem. You can find instructions on how to assemble the device here and the setup guide here. If you happen to be going to SfN2025 this week, stop by the Bonsai Foundation booth and we can demonstrate it!

3. It seems from the diagram that you are routing the TTLs from the soundcard and LED driver as a digital input to the Onix Breakout Board? You can probably get the timestamps from there. However, I am not sure as I have no experience with the breakout board.

[BaptiAllain]

Hi @banchan86!

Thanks for you answer!
The easiest way to do what I wanted was to code task in Arduino, uploading it on the Pico2 to sent digital output signals from the pico2 to the digital inputs of the HARP sound card (IN0 and IN1). My initial goal was to associate with each of the digital input port a different sound index that I loaded though the sound card GUI.
However, I am currently only able to trigger the sound index associated to the digital input 0, but not the one associated to the digital input 1. I can see that the signal is well sent out of the Pico2 using an oscilloscope, but it is like the IN1 port was associated to nothing. Consistently, the timestamped of the input state are only the ones of the DI0. Any idea why this occurs?

I am attaching you my Bonsai code.
Bonsai_code.zip

Thank you!

Best,

Baptiste