Do you remember the last post? I showed the 3D rendering of the river watch RiWa and a few weeks later I have them on my table

They are equipped with the ESP32-S3-WROOM-1U where you can attach an external antenna. I will run some tests later to check the distance I can reach with that combined with ESPNow. 

The Board also comes with an RGB LED (APHF1608LSEEQBDZGKC) which is also used on the nRF52840 USB Dongles. This RGB LED is always available in big quantity and to use it you can utilise 3 GPIO Pins which you draw LOW. Pretty straight forward. I will use it for debugging and status checks.

There is also an RTC (RV-3028-C7) which is ultra low power and has a high accuracy. I attached a supercapacitor to it for time-keeping which will last around 3-4 month if the device has no battery attached to keep the time. 

I also use my favorite Battery charging IC (MCP73831/OT) to charge any type of LiPo Battery like a flatpack or a 18650. 

There is also the pressure sensor from Infineon (DPS368) to measure precise values of pressure and temperature. I already figured out that the temperature is higher then usual due to the fact that it is very close to the ESP board which generates heat but I think that should not be an issue. 

Of course such a prototype does not come without issues: I used 3 of the 4 strapping-pins of the ESP32 and pulled them up for whatever I use them for. I could have used any other Pin but I went for those and I had to patch it on the board. No idea why I did not checked that bafore. 

But besides that the board is running nicely and smooth. I implemented a driver for the RTC and I am able now to set an alarm to sync both devices precisely. Let's see how this is going :)