ppboards - shields for the DE10-Nano board

ppboards are shields that plug into the two 40-pin 2.54mm GPIO pin headers on the DE10-Nano board. They enable custom interfacing of the FPGA module with external world. As an example, a KiCAD design for a simple shield using PMOD connectors is provided (PP_PMOD, described below). This reference design can be used as is or it can serve as a starting point for user customization (different connectors, buffering, etc.).

PP_PMOD

This PulsePins shield board provides output signals broken out on four dual PMOD ports carrying 8 bits each. In addition, the board has dual PMOD connectors for trigger inputs and AUX signals, and regular PMOD connectors for clocking, trigger control and streamer status signals. Other features:

  • all signals on connectors have ESD protection diodes
  • SMA connectors for external clock and for pulse-per-second (PPS) signals; monitoring LED for PPS signal; optinal built-in 50-ohm terminators (enabled by jumpers)
  • SMA connector for one trigger signal; it is connected to a fast comparator with a tunable threshold voltage; optional 50-ohm terminator; monitoring LED
  • two output signals are wired to SMA connectors with 50-ohm line drivers; monitoring LEDs
  • Status LEDs: trigger armed, trigger activated, done, buffer error
  • Activity & heartbeat LEDs
  • QWIIC I2C connector for external modules
  • Optional temperature monitor (I2C interface)
  • Optional 16-bit DAC (I2C interface) with separate low-noise power supply (possible application is frequency tuning of OCXO; in combination with the PPS input from a GPS receiver a PulsePins can serve as a simple GPSDO)
  • Pads for optional crystal oscillators for clocking the PulsePins system
  • Testpoints for troubleshooting
  • GND connection bars for grounding oscilloscope probes

PP_PMOD ppboard

KiCAD schematics and PCB, as well as the gerber files for producing the boards, are available on the GitHub repository.