CREATE Lab Inkjet Test Rig

Qt6/C++ GUI for the inkjet test rig. Runs on a Raspberry Pi connected to a Galil DMC-4080-C022 motion controller and a JetForge (Added Scientific) Xaar printhead controller, with stroboscopic imaging via an IDS UI-3370CP camera and a Teensy 4.0 strobe driver.

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Hardware summary

Component	Interface	Notes
Galil DMC-4080-C022	Ethernet (192.168.42.x)	Axes A (X carriage) and D (reservoir height)
JetForge (Added Scientific)	USB serial	Xaar 128-nozzle printhead controller
Air solenoid valve	Galil extended I/O bit 22	Quick purge
IDS UI-3370CP camera	USB3	Stroboscopic imaging
Strobe Teensy 4.0	USB serial	Custom PCB; firmware in Teensy/

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Setting up a fresh Raspberry Pi

The following assumes Raspberry Pi OS (Bookworm / trixie-based) on a Pi 4 or Pi 5, freshly flashed and SSH-accessible.

1 — Update the system

sudo apt update && sudo apt full-upgrade -y

2 — Install build tools and Qt6

sudo apt install -y \
    git cmake ninja-build \
    qt6-base-dev qt6-serialport-dev \
    libgl-dev

3 — Install gclib (Galil motion library)

Galil publishes a Debian APT repository, but it uses SHA1 signatures which Debian trixie rejects by default. Work around this:

# 3a — Add Galil's repo with the required override flags.
#      (The file likely already exists; check before adding it.)
sudo tee /etc/apt/sources.list.d/galil-release.list <<'EOF'
deb [trusted=yes arch=arm64] http://apt.galil.com/galil stable main
EOF

# 3b — Install
sudo apt update
sudo apt install -y gclib gcapsd

If apt complains about GPG / SHA1: the trusted=yes flag above bypasses the signature check entirely. This is acceptable on a lab-internal machine. You can also import Galil's key manually if you prefer stricter checking — see Galil's online documentation.

Verify the install:

ls /usr/include/gclib.h      # should exist
ls /usr/lib/libgclib.so      # or /usr/lib/aarch64-linux-gnu/libgclib.so

4 — Assign a static IP on eth0

The DMC-4080 ships with a default IP of 192.168.0.42. It can be reconfigured, but the simplest approach is to put the Pi on the same 192.168.42.x subnet (or whichever subnet the controller is on).

# Replace 192.168.42.10 with an address not already in use on that subnet.
sudo nmcli connection modify "Wired connection 1" \
    ipv4.method manual \
    ipv4.addresses "192.168.42.10/24" \
    ipv4.gateway "" \
    ipv4.dns ""

sudo nmcli connection up "Wired connection 1"

Test reachability:

ping 192.168.42.100   # the controller's IP

If the controller was given a different IP during commissioning, update the address in the GUI's Galil Connection bar before clicking Connect.

5 — Configure the Galil axes (first-time only)

The DMC-4080 ships with motor type set to servo (MT=-1). The FSL30 linear stages use stepper motors. If program.dmc has not yet been uploaded to the controller, you need to configure this manually once.

Connect via telnet:

telnet 192.168.42.100

Then send:

MTA=2   (X-axis: stepper, active-low step)
MTD=2   (D-axis: stepper, active-low step)
SHA     (enable X motor)
SHD     (enable D motor)

Once program.dmc is uploaded (see §8), #AUTO does this at every power-up and the manual step is no longer needed.

Axis letter note: The Galil accepts both the axis letter (A, D) and the axis name (X). This project uses the letter form throughout. SHA and SHX are equivalent; SHD has no name alias.

6 — Install IDS peak (optional — camera support)

Download the IDS peak installer for Linux ARM64 from https://en.ids-imaging.com/ids-peak.html.

# Unpack and run the installer (name will differ by version):
chmod +x ids_peak_*_arm64.run
sudo ./ids_peak_*_arm64.run

The SDK installs to /opt/ids/peak by default. If you choose a different path, pass it to CMake:

cmake -DIDS_PEAK_ROOT=/your/path ..

After installing, check that the camera is recognised:

lsusb | grep IDS

7 — Clone and build

git clone https://github.com/YOUR-ORG/TestRig.git
cd TestRig
mkdir build && cd build
cmake .. -DCMAKE_BUILD_TYPE=Release -G Ninja
ninja

The resulting binary is build/TestRig.

8 — Upload program.dmc to the controller

The program.dmc file configures the controller at power-up. Upload it once after commissioning; the controller stores it in non-volatile memory.

From the GUI: (not yet implemented — use Galil tools for now)

From Galil Composer (Windows only): File → Download → select program.dmc.

From gcapsd / telnet:

# Use gclib's program download utility if available:
gcapsd -a 192.168.42.100 -d program.dmc

# Or paste the contents line-by-line into telnet.

After uploading, reset the controller (RS in telnet or power-cycle) and verify the motors energise automatically.

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Running the GUI

./build/TestRig

Typical startup sequence

1. Connect to Galil — enter the controller IP in the connection bar and click Connect. The status dot turns green. Both axis motor-enable buttons update to reflect the motor state.

2. Home the axes (optional but recommended) — click Home (Rev Limit → Zero) on each axis in the Axes tab. The carriage jogs slowly toward its reverse limit switch; when the limit trips, position is defined as 0 mm.

3. Connect to JetForge — go to the Printhead tab, enter the serial port (e.g. /dev/ttyACM0), and click Connect. See the note below about identifying which Teensy is which.

4. Power on the printhead — click Power On.

5. Load a bitmap — click Browse and select a .bmp file. The image is converted to a bitstream and sent to the printhead.

6. Print — use the Test Jet button for a single encoder-triggered pass at a predefined location, or the jog controls to position manually and then trigger a pass.

Identifying the two Teensy devices

Two Teensy devices appear on USB: the JetForge (Added Scientific Xaar printhead controller) and the strobe Teensy (custom PCB for the LED flash). Both enumerate as PJRC serial ports.

To tell them apart:

• Plug in one at a time and note which port appears (ls /dev/ttyACM*).
• Or: send a command in the JetForge's serial command field and watch which port responds.

The JetForge goes in the Printhead tab port field. The strobe Teensy goes in the Camera/Strobe tab Teensy Connection section.

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Solenoid valve wiring

The quick-purge solenoid is controlled by a Galil digital output.

To change the bit number, edit the #define value in src/printer.h:

#define SOLENOID_BIT   22

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JetForge / MJ_START and MJ_DIR bits

The JetForge receives a print-start trigger and a direction signal from the Galil's extended I/O. The default bit assignments (which may need to be changed) are in src/printer.h:

#define MJ_START_BIT  18   // pin 18
#define MJ_DIR_BIT    32   // pin 32

Verify these against the test rig's actual wiring before the first print pass. If the bits are wrong, the printhead will fire at the wrong time or not at all.

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Axis calibration

Both axes use the same FUYU FSL30 linear stage with a Nema 14 stepper and a 2 mm pitch leadscrew at 256 microsteps:

MICROSTEPS_PER_MM = 200 steps/rev × 256 microsteps × (1 rev / 2 mm) = 25 600 cnt/mm

When the X carriage is replaced with the longer stage used on the custom printer, update X_CNTS_PER_MM in src/printer.h if the new stage has a different pitch or microstepping setting. The D-axis constant (D_CNTS_PER_MM) is independent and does not need to change.

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Troubleshooting

Motor does not move after SHA / SHD

• Confirm the #AUTO program has been uploaded and the controller was reset.
• Check MT in telnet: MG _MTA should return 2. If it returns -1, MTX=2 has not been applied — upload program.dmc and reset.
• The controller needs SH before it will accept BG. If the GUI connects before #AUTO finishes (rare), click Enable Motor manually in the Axes tab.

gclib GOpen fails

• Confirm the static IP is set on eth0 and the Pi can ping the controller.
• Confirm gclib and gcapsd are installed (dpkg -l gclib gcapsd).
• The DMC-4080-C022 default port is 23 (telnet). If your network blocks 23, configure the controller to use a different port via Galil Composer.

Camera tab says "unavailable"

• Install IDS peak for ARM64 (see §6).
• Check lsusb shows the camera.
• Run ids_peak_cockpit to verify the camera opens with the IDS tools before trying the GUI.

Two Teensys appear on the same port

• This cannot happen — each USB device gets its own /dev/ttyACMx node. Re-scan with the Rescan button in the Teensy Connection group after plugging in or unplugging.

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Project structure

TestRig/
├── CMakeLists.txt
├── program.dmc               DMC controller startup program
├── README.md
└── src/
    ├── printer.h/cpp         Axis enum, constants, CMD namespace
    ├── galilcontroller.h/cpp Multi-axis gclib wrapper
    ├── asyncserialdevice.h/cpp  Serial base class (from custom printer)
    ├── mfjdrv.h              JetDrive command definitions (reference)
    ├── mjdriver.h/cpp        Added Scientific (JetForge) serial driver
    ├── printheadwidget.h/cpp Printhead control tab
    ├── cameracontroller.h/cpp  IDS peak wrapper (pimpl)
    ├── cameraworker.h/cpp    Acquisition thread
    ├── camerawidget.h/cpp    Camera settings UI
    ├── liveviewwidget.h/cpp  Live frame display
    ├── strobewidget.h/cpp    Start/Stop acquisition
    ├── arduinocontroller.h/cpp  Teensy serial protocol
    ├── arduinowidget.h/cpp   Strobe timing UI
    └── mainwindow.h/cpp      Main window + Axes tab