Caution
This project is under heavy development. All hardware and code in the 'proto' branch is entirely untested. Once hardware has been tested additional branches and tags will be created.
Note
There are licensing concerns regarding the original source files (see FAQ). Therefore only the design output is available here for now.
This project documents the build of a Wifi to BLE gateway specifically to control B2500 type solar storage batteries through esphome. This heavily leans on the great esphome b2500 component https://github.com/tomquist/esphome-b2500. The code provided with this project is only to be seen as example code and was originally generated using the code generator by tomquist.
The gateway integrates an ESP32-S3 in a DIN-rail housing including some status LEDs, an external RP-SMA antenna connector, and 5V power inputs to be supplied by a DIN-rail power supply. Alternatively a USB-C port is provided for debug access and power. The circuit is based on the reference design for the ESP32-S3 including power regulator and reset circuit.
Note
Pictures of the entire assembly will be added once hardware arrives.
The device consists of multiple sub-assemblies:
- Baseboard which contains most of the electronic circuits.
- Piggyback board which only contains two screw terminal blocks for 5V power. This board has a slot into which the baseboard is inserted and soldered in place.
- U.FL to RP-SMA internal antenna cable. Purchased from Amazon / AliExpress
- RP-SMA external antenna. Purchased from Amazon / AliExpress
- Kradex Z105 DIN rail enclosure, also sold under the "Wittko" brand.
- 3D printed front panel for enclosure (to be designed!)
Q: Where are the source files?
A: I quickly created this design in Altium using manufacturer provided symbols and footprints. The licensing implications are unclear to me. Rather than not sharing anything, I am sharing Gerbers and schematics that should allow recreating the hardware for anyone interested.
Q: Why not KiCAD?
A: Because I am much faster in Altium. The goal is to convert the original source code to KiCAD in the future, use only open-source hardware compatible libraries and re-upload.
Q: Why using an 'import' statement in your code?
A: I have two B2500 units that are each controlled from one gateway. This allows separation of common code from instance specific configuration.