pyjeti 0.1.0

Python interface for the JETI specbos 1201 and 1211 spectroradiometers

PyJETI

Python interface for the JETI specbos 1201 (tested) and JETI specbos 1211 (untested) spectroradiometers on Windows.

The package bundles the JETI RadioEx SDK DLLs so no separate SDK installation is needed. See License for details.

Requirements

• Windows (32-bit or 64-bit)
• Python ≥ 3.10
• FTDI D2XX USB driver — typically installed automatically by Windows when you first connect the instrument. If measurements fail or no devices are detected, download the driver manually from ftdichip.com/drivers/d2xx-drivers.

Installation

pip install pyjeti

Or directly from GitHub:

pip install git+https://github.com/SBelgers/pyjeti.git@main

Quick Start

from pyjeti.jeti import Spectrometer

with Spectrometer() as jeti:
    print("DLL version:", jeti.get_dll_version())
    print("Connected devices:", jeti.count_connected_devices())

    serials = jeti.get_serial()
    print("Board serial:       ", serials["board_serial"])
    print("Spectrometer serial:", serials["spec_serial"])
    print("Device serial:      ", serials["device_serial"])

    spd = jeti.measure()
    print("Wavelengths (nm):    ", spd[0])
    print("Irradiance (W/m²/nm):", spd[1])

API Reference

Spectrometer(radio_ex_dll_path=None, simulate=False)

Create a spectrometer handle. Intended to be used as a context manager so the device connection is properly opened and closed.

Parameter	Type	Default	Description
radio_ex_dll_path	str | None	None	Path to a custom jeti_radio_ex64.dll. Uses the bundled DLL when None.
simulate	bool	False	Simulation mode — no hardware required; returns random spectral data.

Methods

Method	Returns	Description
open(device_id=0)	None	Open connection to the device. Called automatically by the context manager.
close()	None	Close the connection. Called automatically by the context manager.
get_dll_version()	tuple[int, int, int]	JETI RadioEx DLL version (major, minor, build).
count_connected_devices()	int	Number of connected JETI specbos devices.
get_serial(device_id=0)	dict	Serial numbers: keys board_serial, spec_serial, device_serial.
measure(integration_time_ms=0, averaging=1, step_nm=1)	np.ndarray	2×N array of [wavelengths_nm, irradiance_W_m2_nm].
validate_device_id(device_id)	bool	Raises if the device ID is out of range.

measure() parameters

Parameter	Default	Description
integration_time_ms	0	Integration time in ms. 0 triggers auto-exposure.
averaging	1	Number of measurements to average.
step_nm	1	Wavelength step size in nm. 1 gives 401 points (380–780 nm).

Return value of measure()

A (2, N) NumPy array:

spd = jeti.measure()
wavelengths = spd[0]   # e.g. [380., 381., ..., 780.] nm
irradiance  = spd[1]   # W m⁻² nm⁻¹

Simulation Mode

Useful for development and testing without hardware:

with Spectrometer(simulate=True) as jeti:
    spd = jeti.measure()
    print(spd.shape)   # (2, 401)

All methods work in simulation mode but return placeholder or random data and emit a UserWarning.

Hardware Notes

specbos 1201

Handheld spectroradiometer, 380–780 nm, 1 nm resolution. Fully tested.

specbos 1211

Similar form factor with extended UV/NIR range. The same API applies, but untested. The current measure() implementation hardcodes 380–780 nm, so wavelengths outside that range will not be captured.

Troubleshooting

count_connected_devices() returns 0
→ The FTDI D2XX USB driver may be missing. Download from ftdichip.com/drivers/d2xx-drivers and install, then reconnect the instrument.

DLL load error / OSError on import
→ If you have a newer version of the JETI SDK installed, pass the path to its DLL explicitly:

Spectrometer(radio_ex_dll_path=r"C:\path\to\jeti_radio_ex64.dll")

Error code exceptions
All JETI error codes are mapped to descriptive messages. The exception text includes the hex code, name, and description, e.g.: Error: 0x03 (JETI_ERR_DEVICE_NOT_OPEN - Device handle is invalid).

License

The Python source code is released under the MIT License (see LICENSE).

The JETI RadioEx SDK DLLs in pyjeti/jeti_drivers/ are governed by the JETI SDK EULA. Distribution as part of an integrated software product is permitted under clause 2a of that agreement. You may not disassemble, decompile, reverse-engineer, transfer, modify, sell, lease, or sublicense those DLLs.