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EEZ Bench Box 3 (BB3) Modular T&M chassis

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Contributors list

GitHub release liberapay

Enclosure 3D model

Ownership and License

The contributors are listed in CONTRIB.TXT. This project uses the TAPR v1.0 license, see LICENSE.TXT.



EEZ Bench Box 3 (BB3) represents a new category of modular Test and Measurement (T&M) equipment. It provides a complete open-source hardware and software framework that bridges the gap between – and combines the best features of – DIY hobbyist tools and professional benchtop equipment. BB3 was inspired by the EEZ H24005 power supply project (OSHWA UID HR000001), which attracted many enthusiasts with its broad feature-set, rich user interface, DIY-friendliness, and fully open-source design. It initially comes with two DC power modules (hence the name of repository modular-psu) and will be expanded with new T&M modules (e.g. multi-channel power source, 2/4-quadrant power module, multi-channel temperature sensor module, data logger, switch matrix, digital I/O expander, function generator, data acquisition module, etc.). BB3 is made up of the following components:

  • BP3C EEZ DIB backplane with power output coupling capability of first two modules
  • AUX power supply board with AC input protection, soft-start/power-up control, DC fan controller and +5 V / +12 V power outputs
  • MCU board based on STM32F769IIT6 32-bit ARM Cortex-M7
  • DCP405, 0 - 40 V / 50 mA / 5 A DC power source module
  • DCM220, dual sync buck 0 - 20 V / max. 4 A module
  • Metal enclosure for housing up to 3 modules with 4.3" TFT LCD. Dimensions: 290 (W) x 123 (H) x 240 (D) mm

Supported technologies

  • SCPI (Reference Guide in PDF)
  • MicroPython (script examples, an example video)
  • MQTT (an intro video)
  • Node-RED integration (an intro video)

Other DIB modules

  • MIO168 Mixed I/O module
  • PREL6 power relays module
  • SMX46 programmable switch matrix module
  • MUX14D dual 7:1 reed relay 2-wire multiplexer

Related topics and links

Where to buy?

Please note that some previous board types and revisions that could be still usable in some cases can be found under previous design folder.

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