ESP32 Versions and Memory - hoylabs/OpenDTU-OnBattery GitHub Wiki

Due to the growing size of the code and the flash memory limitations of the common ESP32 boards (4 MB) on the market today, we know that sometime in the future, ESP32 boards with a minimum of 8 MB of flash memory will be required to run the OpenDTU-OnBattery firmware. See Announcement in #1025 for more details.

Note: Users report that some board-versions have WiFi problems https://github.com/helgeerbe/OpenDTU-OnBattery/issues/935#issuecomment-2138018534

Preferred are boards with the ESP32-S3, and -N8R, -N16R, -N32R in their names, indicating 8 MB, 16 MB or 32 MB flash memory, respectively.

ESP32-S3 Versions B

ESP32 16MB vs 8MB Ali

ESP32-S3_DevKitC-1_pinlayout_v1 1

Important info for those intending to use the 5V as Output

At its default form, the 5V Pin is for Input current ONLY! There is a Solder Bridge marked IN-OUT near PINs 11-12 which you must close, if you want to have 5V OUTPUT Wrong 5V - Solution - Copy

Posibilities / Ready-Boards

You can put together your 8 MB or 16 MB system using individual components (example below).

Wiring_ESP32_Symbol - Victr1Victr2PylontechHuaweiRelaisCMT2300upd

Alternatively, there are a few 8 MB or 16 MB integrated boards available, or under development, which combine many peripheral connections. Examples:

There is OpenDTU-Fusion Board available:

with CANBus/VE.Direct add-on board for Battery CANbus and Victron MPPT/SHUNT communication:

There is OnBattery-Pro board (currently (May 2024) undergoing Beta-testing):

OnBatery-Pro

There is an "OpenDTUonBattery Platine mit Maximal-Ausbau DC/DC und JK-BMS Stecker" board with direkt JK-BMS and Huawei Rectifier option (currently (May 2024) under development):