One day my oscilloscope died. I had picked up the Raspberry Pi 400 a year earlier with the vague intent of creating a cyberdeck - this was the sign to do it.


  • Folding
  • Battery powered
  • Potentially useful for something
  • Large screen
  • Able to be dismantled
  • aesthetic


(Most of) Parts:

  • Siglent SDS 1072CML+ (non-booting)
  • Raspberry Pi 400
  • LimeSDR
  • USB Hub
  • Panel mount ethernet socket
  • Panel mount USB A female -> USB A male
  • Panel mount USB B female -> USB A female
  • 4x Panel mount BNC -> SMA
  • Panel mount DSUB-9 (from a PC PCI expansion slot plate)
  • USB 3.0 extension cable
  • Micro-HDMI -> HDMI -> Mini HDMI
  • External USB powerbank (not shown)
  • HDMI -> LVDS adapter (e.g. - not my seller, multiple sources available)

Raspberry Pi 400 Mounting Mechanism:

From Jeff Gerling's video (, I knew that the Raspberry Pi 400 has a large heatsink - far greater than the size of the PCB. I decided to drill & tap this heatsink for some M3 mounting bolts (go get yourself some taps, they are GREAT).

The LimeSDR is connected via USB3.0 directly to the Raspberry Pi 400. The two Oscilloscope inputs are connected to the channel 1 and 2 wideband inputs respectively. The front ext trigger is used as Tx1_1. The rear pass/fail port is a SMA connection, and is used as Tx2_1.

The LimeSDR is mounted in front of the fan, as active cooling is required. Adhesive aluminium heat sinks are applied to the LM chip, and the FPGA.

Mounting to Oscilloscope:
Uses M3x14 bolts into the plastic casing of the oscilloscope. These holes are tapped.


All oscilloscope internals, barring control panel and screen are removed. LimeSDR is mounted on a 3D printed plate, directly in front of the fan. A power distribution board, made out of protoboard, is placed on top. This powers the fan and the LVDS/HDMI adaptor board, and is connected to the USB B socket on the rear. A separate power board is used to avoid over-currenting the Raspberry Pi 400.

The cables are routed through a hole cut in the bottom:


Front USB is connected to an internal USB hub. Rear USB B is for power. Rear serial (DB-9) is connected to an internally mounted PL2303. Ethernet port is connected through to the Raspberry Pi 400 directly.

Oscilloscope Controls:

Intent is to use a STM32 as a USB HID to interface to the control board and dials on the front, as a combination of Mouse & Keyboard. Partial effort into reverse-engineering the board has occurred.

Seems to use some decade counters to multiplex the buttons, with some analog multiplexers to read.

It folds!: