The SD-Dev carrier board

The Signaloid SD-Dev is a compact carrier board and development system designed for testing and characterizing the Signaloid C0-microSD.

SD-Dev port
Figure 1: SD-Dev port diagram.

When you connect the Signaloid SD-Dev to a host computer via USB, it acts as a generic USB-to-SD adapter, exposing one microSD and one full-size SD slot to the host (peripheral mode). Alternatively, you can attach a Raspberry Pi CM4 or CM5 to the carrier board, producing a compact single-board computer (SBC) with hot-swappable FPGA modules in a standalone configuration. In this mode, the carrier board provides power measurement capabilities for the on-board FPGA modules and allows you to power cycle them programmatically.

When using the SD-Dev without an onboard Raspberry Pi compute module (peripheral mode), you must connect it to your host computer via the PWR+D port. When using it with a compute module (standalone mode), power it via the PWR port so that you can use the P0 and P1 ports to connect peripherals to the Raspberry Pi compute module.

Getting started with the Signaloid SD-Dev

To get started with the SD-Dev, view the SD-Dev quickstart guide.

Carrier-Board Specifications

  • Compact design with the following I/O:
    • 2 USB Type-C downstream ports
    • 1 USB Type-C upstream port
    • 1 USB Type-C upstream power-only port
    • 1 Micro HDMI port
    • JST connectors for SPI and I²C peripherals
  • One full-size SD slot and one microSD slot for Signaloid C0-microSD boards or regular storage cards
    • SD card detection
    • Programmable power cycling
    • Power measurement
    • Open-top microSD socket allows you to probe the Signaloid C0-microSD debug pads
  • Dual function (peripheral and standalone modes)
  • Board outline of 57 x 57 mm

Flashing the eMMC of a Raspberry Pi compute module.

To flash the onboard eMMC of your Compute Module using the Signaloid SD-Dev board, please refer to the official Raspberry Pi documentation. Note that the SD-Dev board does not include a disable eMMC Boot jumper. Instead, prior to connecting the SD-Dev to the host computer, press and hold the onboard push button and continue with the flashing process.