DAQiFi is an open-source data acquisition platform and the Nyquist is a multi-function data acquisition device (DAQ). This wiki is intended to serve as a reference for the Nyquist device firmware.
Contents
- SCPI Interface – Command reference for device control
- LED Indicator Patterns – Status LED blink patterns and meanings
- Capabilities JSON Schema – Schema reference for the
CONFigure:CAPabilities:JSON?discovery query
Control Interface
The Nyquist is configured using Standard Commands for Programmable Instruments (SCPI) commands. SCPI commands are simply text based commands following the SCPI protocol. SCPI commands can be issued directly through USB (virtual COM port) or via TCP.
See SCPI Interface for details.
Streaming Interface
The Nyquist will respond to SCPI commands with ASCII based responses. Except when streaming is invoked. When streaming, the Nyquist encodes device data using Google’s Protocol Buffers (protobuf). This is an efficient method of sending data in limited bandwidth situations such as WiFi. The protobuf fields are defined in the DaqifiOutMessage.proto file.
Operation
Power On
When plugged into a USB power source, the micro automatically receives “power.” Currently, (mostly for ease of debugging), the board will connect to the PC and allow the USB CDC device to connect without pressing the power button. However, that state is still technically “powered-off.” To power the board, the user must press and hold the button for ~1s. Then the white LED should illuminate. Alternatively, the user can issue SYSTem:POWer:STATe 1 to achieve the same goal.
See LED Indicator Patterns for a complete guide to LED status indicators.
Configure WiFi
The Nyquist is easily configured using the Windows App. However, users might want to manually configure the device or automate configuration which can be done using SCPI commands.
NOTE: Device must be fully powered-on (LEDs active) before WiFi settings are modified.
The example below assumes existing infrastructure (router) uses WPA/WPA2 with passphrase. Once the settings are applied and saved, the board needs to be rebooted and powered on to connect to the network.
SYSTem:COMMunicate:LAN:NETType 1
SYSTem:COMMunicate:LAN:SSID “WiFi_Test”
SYSTem:COMMunicate:LAN:SECurity 4
SYSTem:COMMunicate:LAN:PASs “WiFi_Test”
SYSTem:COMMunicate:LAN:APPLY
SYSTem:COMMunicate:LAN:SAVE
SYSTem:REBOOT
Source of truth: daqifi/daqifi-nyquist-firmware wiki → 00-DAQiFi-Nyquist-Firmware · Edit on GitHub · this page is auto-synced; edit upstream to update.