Description

This module provides 8 analog voltage output channels, which are independently controlled by either the Bpod state machine, or a second Bpod module. With its default firmware, the 8-channel analog output module can store arbitrary waveforms and play them on trigger with low latency. Two alternative firmware files allow the module to deliver parametric voltage pulse trains for stimulation, and to generate analog output signals mapped with a transfer function from an input module data stream.

Specifications

Compatability

• Interfaces with Bpod state machine v0.7 or newer.

Processor

• ARM Cortex M4: Freescale MK66FX1M0VMD18 as part of the Teensy 3.6 development platform
• 180MHz Clock Speed
• 256KB sRAM
• Programmable using 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

• 8 output channels, driven by two 4-channel 16-bit precision DACs: 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-25kHz. (up to 50kHz with ch5-8 disabled)
• 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, playback start and stop events can send event codes to the Bpod state machine.
• MATLAB API provided as part of the Bpod repository.

Memory

• 8GB MicroSD card included

Dimensions

• L: 16cm (6.2")
• W: 12cm (4.5")
• H: 4cm (1.5")