Modular DAQ (MODAQ)

MODAQ (Modular Data Acquisition) is USC LPL's next-generation DAQ hardware architecture, built to replace the lab's legacy discrete wiring assemblies with a reliable, PCB-based modular system. Where the legacy system relies on screw terminals and large wire buses that degrade under repeated transport and reconfiguration, MODAQ eliminates intermittent connection faults by routing everything through soldered PCB interconnects.

‍

The system centers on a compact 4-layer backplate that distributes 24V, 12V, and 5V power while routing signals to daughter boards mounted on both faces. Each 50×70mm daughter card connects via a rotation-tolerant interface—designed so boards physically cannot be plugged in incorrectly—and provides 4 signal channels per slot, giving a single backplate access to up to 16 sensors or actuators. Front-side modules handle sensor signal conditioning and acquisition; back-side modules manage data aggregation and handoff to processing and telemetry.

‍

MODAQ's daughter board ecosystem covers the full range of LPL's instrumentation needs: solenoid valve control (relay and MOSFET variants), pressure transducers, load cells, flow meters, and thermocouples. Adding or swapping a sensor type means pulling one card—no system redesign, no rewiring.

‍

The architecture reduces test stand setup time by 1–2 hours per configuration, cuts hardware replacement cost (less than half of equivalent discrete assemblies), and enables daughter card swaps in under a minute. MODAQ is currently in its first iteration and its second iteration is already being worked on. The next generation backplate moves to an 8-layer stackup with 8 signal channels per daughter card slot — doubling throughput to 32 sensors or actuators per backplate, further reducing the overall DAQ architecture footprint. The second iteration also introduces a swappable "hat" interface on the back side, allowing the system to be paired with different processing modules — Raspberry Pi, Arduino, Teensy, and others — without any changes to the backplate or daughter card ecosystem.