Description

This module provides 4 analog voltage output channels, which are independently controlled by either the Bpod state machine, or a second Bpod module. With its default firmware, the analog output module can store arbitrary waveforms and play them on trigger with low latency. Alternatively, it can run Pulse Pal firmware to deliver parametric voltage pulse trains for stimulation, or closed-loop firmware to generate analog output signals mapped with a transfer function from an input module data stream.

Analog Output Module 2 features an upgraded microprocessor with more memory and improved USB bandwidth. This translates into a larger number of waveforms that can be stored on the device, faster sampling, and shorter dead-time between trials.

Specifications

Compatability

• Requires Bpod v0.7 or newer.

Processor

• ARM Cortex M7: NXP i.MX RT1060 Crossover as part of the Teensy 4.1 embedded computing platform
• 600MHz Clock Speed
• 1MB RAM
• Programmable in the Arduino language

Inputs

• Bpod State Machine (via RS-485 buffered UART, 1.3Mb/s)
• Second Bpod Module (via RS-485 buffered UART, 1.3Mb/s)
• USB

Outputs

• 4 output channels, driven by a 16-bit precision DAC: Analog Devices AD5754R
• Output Range: software selectable among:
• [0 to +5V]
• [0 to +10V]
• [0 to +12V]
• [-5 to +5V]
• [-10 to +10V]
• [-12 to +12V]
• 20mA short-circuit current, >2kΩ load for specified performance

WavePlayer Firmware

• Up to 64 waveforms can be stored on the device (loaded by USB at ~8Mb/s)
• Waveform size: up to 1M Samples per waveform
• 3-byte messages trigger the device, specifying waveforms and target channels (pre-selection not required)
• Playback start/stop latency: <100μs
• Configurable sampling rate: 1Hz-100kHz.
• Trigger options:
• Normal mode (trigger bytes during playback ignored by targeted channels)
• Toggle mode (trigger bytes during playback stop targeted channels)
• Master mode (trigger bytes during playback instantly replace current waveform on targeted channels)
• Optionally, on playback start and stop, the module can send event codes to the Bpod state machine.
• MATLAB API provided as part of the Bpod repository.

PulsePalModule Firmware

• With this firmware, the module functions as a Pulse Pal device - it plays parametrically defined voltage pulse trains on trigger.
• Serial triggering enables Bpod to trigger any subset of channels with a single byte message.
• Trigger toggle mode enables stimulation to be selectively active between Bpod states, or for the duration of Bpod's global timers.
• 4 custom Pulse trains defined by up to 10,000 pulse onset times and voltages can be loaded on any channel.
• MATLAB API provided as part of the Bpod repository

Memory

• 16GB MicroSD card included

Dimensions

• L: 10cm (4")
• W: 12cm (4.5")
• H: 4cm (1.5")