To remove the EEZ BB3 from its packaging and check the equipment for completeness, proceed as follows:

  • Check the package for damage
  • Carefully unpack the EEZ BB3 and the accessories
  • Check the package contents for completeness using the Delivery list and package contents
  • Check the equipment for any visible shipping-related damage or other mechanical problems, e.g. loose parts inside

If there is damage or anything missing, contact the supplier and the carrier who delivered the EEZ BB3. Do not operate the EEZ BB3 in this case.


Retain the original packing material. If the EEZ BB3 needs to be transported or shipped later, you can use the material to protect the exposed and fragile elements on the front panel.


The EEZ BB3 must be stored in dry, closed, indoor premises. If the EEZ BB3 was transported under extreme temperatures, it is recommended that you allow a minimum of two hours to reach the appropriate temperature before operating the EEZ BB3.


4.1. Delivery List

4.1.1. Assembled unit (coming soon)

The EEZ BB3 comes with the following components:

  • EEZ BB3 preloaded with selected peripheral modules
  • Two AC mains fuses for 115 V or 230 V operation
  • AC mains cable for the selected region
  • Read me first leaflet with links to online documentation
  • Set of DC power cables, clip-on probes and crocodile clips (optional)

4.1.2. Kit version

The EEZ BB3 kit is not an end user product. As such it was not put into any conformance testing and it may not comply with some or any technical or legal requirement that are applicable to finished products including, without limitation, directives regarding electromagnetic compatibility, FCC, CE, or UL.


Assembling and using the EEZ BB3 requires an understanding of electronic circuits. Additionally, basic computer knowledge is recommended for performing firmware upgrades.

The EEZ BB3 comes in different kit versions. Typical content of the kit version:


  • Enclosure kit
  • Wire harness, nuts&bolts package
  • Set of basic modules (i.e. AUX-PS, MCU and BP3C)
  • Set of selected peripheral modules
  • Read me first leaflet with links to online documentation
  • Set of DC power cables, clip-on probes and crocodile clips (optional)

Kit assembly instructions are available on the following link:


4.2. Placing the EEZ BB3

If the EEZ BB3 is operated on a bench top, the surface must be flat. You can place the EEZ BB3 horizontally, or in a slope position by unfolding the front feet.


Fig. 1: Adjustable front feet


The feet can fold in if they are not folded out completely or if the EEZ BB3 is shifted. Collapsing feet can cause injury or damage the EEZ BB3.

  • Fold the feet completely in or out to ensure stability of the EEZ BB3.
  • Never shift the EEZ BB3 when the feet are folded out.
  • When the feet are folded out, do not work under the EEZ BB3 and avoid placing anything underneath.

The front feet in folded out position can break if they are overloaded. The overall load on the folded out feet must not exceed 50 N. If the front feet are folded in, it is possible to stack the EEZ BB3 with more instruments securely.


4.3. Starting the EEZ BB3

The EEZ BB3 is equipped with an AC power supply connector, (IEC C14 type) which can be used with different AC power voltages in wide range without need to adjust manually input voltage or frequency.


IMPORTANT: The EEZ BB3 must only be connected to an outlet that has a functional ground contact

  • Check the AC line voltage.
  • Check the fuse type and if necessary replace the fuse type suitable for the line voltage.
  • Connect the EEZ BB3 to the AC mains using the supplied power cable.

4.4. Replacing the fuses

The EEZ BB3 has main power fuses, which are located on the rear panel of the unit. Handling the fuses while power is on can lead to electric shock. Therefore, before opening the fuse holder (see Fig. 2), make sure that the EEZ BB3 is disconnected from AC power.


Fig. 2: Opening the fuse holder


To replace the fuses the EEZ BB3 has an externally accessible fuse holder combined with the IEC socket.


The nominal current of the fuse depends on the line voltage and number of installed power modules. Select the fuses according to the voltage of the AC line, as specified in Table 1. Fuse size is 20 x 5 mm of time-lag type and has to be rated for the selected AC line voltage.


No. of power modules




115 V

2 x 3.15 A

2 x 6 A

2 x 8 A

230 V

2 x 2 A

2 x 4 A

2 x 6 A

Table 1: Fuses selection

4.5. Battery replacement

The CR2032 coin cell battery is used as a power backup for the RTC. It uses a non-rechargeable lithium battery that will need to be replaced when its voltage drops to approximately 90 % of its rated value. The current battery value can be viewed on the System information page.


To access the EEZ BB3 interior, First, turn off the EEZ BB3 and unplug the power cord from the back, then remove the top cover, which is secured by four screws (two on each side).


Fig. 3 shows where the battery is located. You can remove the existing battery by pinching it. When inserting a new one, keep in mind the polarity (+ side must face inwards).


Do not use metal pliers instead of your fingers to insert or remove the battery as it may cause a short circuit. If you cannot reach the battery with your fingers, use a plastic tweezers instead.


Do not expose the battery to high temperature or fire. Keep it out of the reach of children. Improper change of a battery may cause damage, fire or explosion.


Fig. 3: Coin battery location


4.6. Micro SD card (non-volatile memory)

The EEZ BB3 uses a micro SD card as a non-volatile memory. Due to its small size, extra care will be required when inserting and pulling out to prevent damage to the card or socket.


Attention should also be paid that the card is inserted correctly into the socket otherwise it could fall inside the enclosure. Therefore, it is recommended that the EEZ BB3 be completely switched off (not in standby mode!) when the card is inserted.


Fig. 4 shows how the card should be positioned when inserted: its connectors should be facing up (i.e. must be visible).


Fig. 4: Micro SD card insertion


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  • Location: Indoor, no direct sunlight, dust free, almost non-conductive pollution (note below)
  • Relative Humidity: < 80 %
  • Altitude: < 2000 m
  • Temperature: 0°C to 40 °C

(Pollution Degree) EN 61010-1:2001 specifies the pollution degrees and their requirements as follows. The EEZ BB3 falls under degree 2. Pollution refers to “addition of foreign matter, solid, liquid, or gaseous (ionized gases), that may produce a reduction of dielectric strength or surface resistivity”.

  • Pollution degree 1: No pollution or only dry, non-conductive pollution occurs. The pollution has no influence.
  • Pollution degree 2: Normally only non-conductive pollution occurs. Occasionally, however, a temporary conductivity caused by condensation must be expected.
  • Pollution degree 3: Conductive pollution occurs, or dry, non-conductive pollution occurs which becomes conductive due to condensation which is expected. In such conditions, equipment is normally protected against exposure to direct sunlight, precipitation, and full wind pressure, but neither temperature nor humidity is controlled.

3.1. Storage environment

  • Location: Indoor
  • Relative Humidity: < 70 %
  • Temperature: −10 °C to 70 °C


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BB3 two channel kit assembly instructions



A BB3 starter kit and two full-featured DCP405 single-channel (40 V, 5 A) peripheral power modules, including an AC/DC power module for each. A two-channel programmable power source with advanced features: remote sensing, remote programming, a down-programmer, and additional OVP (with crowbar).


Enclosure & Bare Boards kit assembly instructions



A BB3 enclosure kit with a wire harness, nuts and bolts for the three core modules, a 4.3" TFT touchscreen display, an encoder knob, and an 80 mm fan. Includes a set of bare PCBs for building the three core modules (AUX-PS, MCU STM32F7, and BP3C DIB 3-slot backplane) as well as PCBs for building one DCM220 two-channel peripheral power module and two DCP405 single-channel peripheral power modules. Suitable for builders with the necessary skill, time, and patience.








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The Envox team thanks you for your trust and support – you have ensured that the goal of the crowdfunding campaign was achieved and the production of the EEZ BB3 came to life.


We believe you will like the EEZ BB3 which is offered completely as open source which we will continue to improve and upgrade. Your comments and feedback is therefore highly appreciated.


If you need assistance, please contact us or post your problem on EEZ Discord server or on the EEVblog forum.

Feel free to open a New issue in GitHub (hardware or firmware related). Please check first to see if a similar issue already reported.


* * *


EEZ BB3 kit is not an end user product. Although the EEZ BB3 has been designed taking into account safety recommendations and using certified components, it has not yet been subjected to conformance testing and it may not comply with some technical or legal requirements that are applicable to finished products including, but without limitation, directives regarding electromagnetic compatibility, FCC, CE, or UL.

Assembling and using the EEZ BB3 requires an understanding of electronic circuits and basic computer programming skills. By using the kit, the user acknowledges and agrees that any use of assembled EEZ BB3 is solely at the user’s own risk, and that user is solely responsible for compliance with all legal and regulatory requirements in connection with such use.


Envox d.o.o. supplies EEZ BB3 kit AS IS, without any warranties, with all faults, at the buyer’s and further users’ sole risk. The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user indemnifies Envox d.o.o. from all claims arising from handling or using any part of the EEZ BB3 neither assembled nor in kit form.


Please note that while EEZ BB3 power outputs are of low voltages (below 50 VDC), they may still pose a threat of personal injury. Further, AC mains power voltages may be involved when assembling and using the EEZ BB3. High voltages can be lethal and in the worst case may lead to electrocution and death.


All documents, manuals, and information on the EEZ BB3 project web pages (please start with assembly instructions) and GitHub repository are intended only to assist the reader in the assembly and use of the product. Envox d.o.o. shall not be liable for any loss or damage arising from the use of any information or any error or omission in such information or any incorrect use of the product.


Use the following link to the User manual, and the SCPI Reference guide.


See also Crowd Supply’s Proclamation of users rights.






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MQTT (Message Queuing Telemetry Transport) is a lightweight publish/subscribe messaging protocol designed for M2M (machine to machine) communication. MQTT is fast becoming one of the leading protocols for IoT (internet of things) deployments.


Thanks to MQTT support, EEZ BB3 can be easily and securely remotely monitored and controlled. Furthermore, EEZ BB3 can be integrated into existing IoT infrastructure.


For efficient and fast deployment, it is recommended to familiarize yourself with the basic terms of the MQTT protocol. An example of an interaction with EEZ BB3 via the MQTT description protocol is described below using the MQTT Explorer application which is available for free at


Please note that topics are case-sensitive, i.e. <hostname>/system/exec/restart is not equal to <hostname>/system/exec/RESTART.


15.1. Set channel parameter using subscribe topic


Start MQTT Explorer and enter parameters for connection to your MQTT server (aka broker): Name, Protocol, Host, Port, Username and Password.





For example, if we want to set the output voltage on a channel, it will be necessary to type in the Publish section as topic <hostname>/dcpsupply/ch/<ch>/set/u. In this example, the hostname is bb3-zd and to set the output voltage on channel 2 it will be necessary to type as topic bb3-zd/dcpsupply/ch/2/set/u, set its value to 30 (type is json) and click on the Publish button.





The newly set output voltage value will be visible after the topic bb3-zd/dcpsupply/ch/2/umon is refreshed.




15.2. Drawing a topic graph


Select a topic of interest, and click the graph icon in the History section





The default settings graph will appear below the topic list.





Graph settings can be changed by selecting the settings icon.




15.3. Publish topics

15.3.1. System




Returns 0 when EEZ BB3 enters standby mode, or 1 when in active mode


Latest message from the event log formatted as [<event_id>, <event_type>, <event_message>].

For example: [14011, "Info", "Ch2 output on"]


RTC battery voltage


AUX sensor temperature


Cooling fan status and speed


Total active time of the EEZ BB3 (MCU module). Resolution is 1 minute


Duration since the EEZ BB3 was turned on. Resolution is 1 minute

15.3.2. Dcpsupply




Status of the channel output


Returns set output voltage


Returns set output current


Measured output voltage


Measured output current


Measured channel temperature


Channel total active time. Resolution is 1 minute


Duration since the last on time. Resolution is 1 minute

15.4. Subscribe topics

15.4.1. System




Sending 1 initiates EEZ BB3 restart


Send 0 to enter standby mode, or 1 to return back


Initiate trigger system by sending 1


Abort trigger system by sending 1


Displays pop-up message on the EEZ BB3 display


Use to clear text message sent as described above


Recall user defined profile by sending profile number (0 to 9)

15.4.2. Dcpsupply




Sets channel output state: 1 to On or 0 to Off


Sets output voltage


Sets output current


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