
EEZ BB3 (Bench Box 3)
The EEZ BB3 continues the well-accepted and proven EEZ H24005 by adding greater modularity and going beyond DC power source functionality, thus opening up the possibility of adding new modules for data acquisition, control of multiple digital and analog inputs and outputs, etc.
Quick facts
- Modular design – use up to three modules in any combination
- Large color touchscreen display with customizable and responsive GUI
- MicroPython scripting, Node-RED integration
- MQTT support
- DC power source up to 6 channels, max. 450 W
- Easily programmable with 400+ SCPI commands
- Built in Ethernet, USB and UART for remote control
- Fast boot, FreeRTOS firmware
- Quiet operation thanks to multi-sensor fan speed control
- Software simulator
Typical applications
- Product development and debugging
- Laboratories and educational facilities
- Quality control and assessment
- Automobile electronic circuit testing
- Production automation testing
- Device or circuit characteristic verification and troubleshooting
The EEZ BB3 comes fully packed with features that make it increasingly attractive for a growing number of use cases. Below are some of the most pronounced features that will make daily work more efficient and safer by reducing the number of possible errors. Many details are well polished thanks to quality user feedback and our ability to implement them quickly because all development takes place in our premises.





Feature |
Benefit |
High resolution TFT color touchscreen display for straightforward operation |
Simplifies and speed up setup and operation. The large touchscreen enables faster setup time, thanks to quick navigation through the menus to access all functions and settings. The home page gives a clear overview of all installed modules. Each channel can be selected for a more detailed view with a wide variety of additional information. |
Mix and match multiple modules |
Identical or different modules can be quickly installed in any combination on a "plug and play" basis to address different user cases. The unified user interface provides a steep learning curve. |
On-module EEPROM |
Module specific information such as activity counters, calibration data, etc. are stored in the EEPROM of the module and remain preserved regardless of whether the module is moved within the same or another chassis. |
Simple firmware upgrade |
Upgrading BB3 firmware and firmware on modules with up to date versions is a painless and quick operation that can be done in a few simple steps. |
Color themes, customizable module colors and labels |
Setting the module colors according to user preferences increases readability and reduces usage errors. User-defined labels instead of generic ones further help reduce misinterpretations and simplify use. |
Power control and fast boot |
The AC mains inputs of power module is under firmware control so that it is possible to turn it on and off remotely (i.e. using MQTT from the other side of the world). Implemented soft-start limits in-rush current to reduce stress on AC mains. A fast boot makes BB3 ready for action in within three seconds. |
All channels are independently controlled |
Supports powering up a circuit with multiple voltage levels (such as a digital circuit) that must be turned on in a specified time sequence. |
On-screen keypad or rotary knob with step definition for entering numerical values |
Simplifies fast, precise entry of output values. |
User profiles to store frequently used configurations in any of 10 setup memory locations |
Saves times when repeating tests. |
Programmable sequences (lists) |
Arbitrary waveforms can be generated for voltage and current. Function can be configured and executed locally or remotely. Low jitter of generated sequence allows generating of precise multi-pattern waveforms. |
Digital I/Os on the front panel |
Conveniently located are easily accessible that can be connected to an external device that can generate a trigger event, or device under test can interact directly with BB3 by sending SCPI commands and changing its parameters via a simple UART interface, thus improving the automation of the entire process. Additionally the DOUT2 output can be configured as a square wave generator. |
NTP |
Support for NTP (Network Time Protocol) ensures that BB3 uses the most accurate time in measurements and activity recordings. |
USB OTG mode |
The USB port supports OTG (On-The-Go), so in addition to device mode, it can also be in host mode for connecting a USB mouse or similar peripherals. |
Removable micro SD card |
With card capacity of 8 GiB it is possible to store hundreds of hours of data logging, an almost unlimited number of MicroPython scripts, screenshots, programmable lists and activity logs. The card can be replaced with a larger capacity as needed. The data can be accessed directly via a PC or the card can be detached so that the data can be accessed using an external card reader. |
Protection functions: OVP, OCP, OTP, OPP |
If set limit for output voltage, current, temperature or power is reached, the affected output channel will be automatically switched off and a message will be displayed. In case when additional safety is needed it is possible to deactivate all outputs or even put a whole chassis in standby mode. |
Speed controlled cooling fan |
The noisy environment is tiring and annoying in the long run, so to stay as quiet as possible the BB3 uses a fan with linear speed control defined by a temperature measured at multiple points. |
DCP405: remote programming (modulation input) |
Allows that programmed voltage follows external analog signal that come from connected device or other module or external instrument. |
DCP405: remote sensing |
Ensures that programmed voltage is accurately applied to the load. |
DCP405: Down-programmer |
Allows discharging voltage quickly even in case with connected device with large input capacitance. |
DCP405: Small and power efficient power modules |
Combination of switching pre-regulator and additional linear control reduces size and increases power efficiency delivering up to 155 W. |
Software simulator |
The software simulator is a useful tool that we use in our own development because it shortens the prototyping time and is available to anyone who needs to speed up the development of their own modules for BB3. Furthermore, it also offers an attractive alternative to the classic “try before buy” process without the need to negotiate evaluation terms and waiting for a physical sample to arrive. |
Open software and hardware design |
BB3 is a certified open hardware design. Openness offers multiple and long-term benefits and preservation of investment: design can be checked in the presale evaluation process, complete freedom in case of servicing, modification and upgrades as well as reducing long-term risk associated with original manufacturer availability. The community gathered around BB3 can shorten the learning curve, allow the exchange of user experiences, can act as technical support, etc. |
- STM32F769 32-bit ARM Cortex®-M7 MCU, 216 MHz, 2 MiB Flash, 512 KiB SRAM
- Digital I/O: 2 x buffered inputs and 2 x buffered outputs (alternative functions: UART, PWM out)
- Rotary encoder with switch
- 1 x user switch
- 3 x dedicated SPI channels (2 x Chip selects per channel), 40-pin IDC connector (DIB v1.0)
- Battery backup (CR2032 button cell type)
- USB FS OTG
- Ethernet PHY (10/100 Mbit/s)
- 32 KiB I2C system EEPROM
- 8 MiB SDRAM
- 8 GiB Micro SD card
- 4.3” TFT color resistive touchscreen display with brightness control
- SWG/JTAG connector (optional)
- Small on-board speaker
- Four power relays for various power outputs coupling
- Full range autoswitch AC input (115 / 230 Vac)
- AC Soft-start (In-rush current limitation) and stand-by
- AC IEC C14 inlet with two 20 x 5 mm fuse
- AC power switch
- AC power input protection and EMI filter
- Standby LED indicator
- Ø80 mm DC cooling fan with speed control
- Kensington lock slot™
- Compact size: 290 (W) x 123 (H) x 240 (D) mm
- Weight (populated with 2 x DCP405 and 1 x DCM224): 4.05 kg
- Remotely controlled by 400+ SCPI commands using the EEZ Studio of similar SCPI controllers, MQTT, Node-RED, etc.
- EMC compliance (not applicable to kit version): EN61326-1:2013, EN IEC 61000-3-2:2019, EN 61000-3-3:2013+A1:2019
- LVD compliance (not applicable to kit version): EN 61010-1:2010, EN 62311:2008
Firmware and MicroPython scripts
Firmware images
System (master) and module firmware download procedures are described in BB3 User manual, Chapter 13.
Project |
Type |
Source |
Firmware image (download .hex file) |
|
System |
|
|||
Module |
|
|||
Module |
|
|||
Module |
|
|||
Module |
dib-prel6-fw |
Work in progress |
||
Module |
dib-mio168-fw |
Work in progress |
Note that the DCP405 module unlike other modules does not have an on-board MCU so it does not require its own firmware.
MicroPython scripts
Consult BB3 User manual, Chapter 16 for scripting with MicroPython.
Script name |
Type |
File location |
Module initialization |
Python script |
|
Resource file |
||
Curve tracer |
Python script |
|
Resource file |
||
Diode tester |
Python script |
|
Resource file |
||
Op-Amp Calculator |
Python script |
|
Resource file |
||
Parallel and Series Calculator |
Python script |
|
Resource file |
||
Voltage Divider Calculator |
Python script |
|
Resource file |
Documentation

This manual contains reference information for programming open hardware/open source EEZ BB3 Test & Measurement chassis over the remote interface using the SCPI programming language.

EMC certificate No. 80210009 issued by Končar Institut – Certification Department SCERT (Feb 25, 2021)
Test report No. 21583EMC20008 (Feb 3, 2021)

LVD certificate No. 80210009 issued by Končar Institut – Certification Department SCERT (Feb 25, 2021)
Test report No. 21583SIG20008 (Feb 17, 2021)
External links



