Components

ESP32-WROVER-E (has PSRAM compared to wroom, the IE version doesn't have pcb antenna) https://www.mouser.de/ProductDetail/Espressif-Systems/ESP32-WROVER-EM213EH2864PH3Q0?qs=sGAEpiMZZMu3sxpa5v1qrgqRbH4gaXhhyqOoBsYWKak%3D
HX711 ADC for weight scale mouser doesn't have it?

Tools

easyeda has lcsc library, to import in kicad use: https://wokwi.com/easyeda2kicad

22u 3x (2x esp32 power + 1x ESP_VDD)
- options: CL21A226MAQNNNE 25V $0.05 (basic part) CL10A226MQ8NRNC 6.3V $0.02 (basic part)
10u 2x (1xHX_VDD + 1xHX signal)
- options: CL21A106KAYNNNE 25V $0.03 CL10A106KP8NNNC 10V $0.0185
0.1u 9x (2x programmer button + 1x ESP_EN + 1xESP_VDD + 2xHX_VDD + 3xHX_SIGNAL )
- options C1005X7R1H104KT000F 50V $0.012 (extended part, but huge stock)

based on https://www.espressif.com/sites/default/files/documentation/esp32-wrover_datasheet_en.pdf
and https://dl.espressif.com/dl/schematics/esp32_devkitc_v4-sch.pdf
further resource https://github.com/adafruit/adafruit-HUZZAH32-ESP32-Feather-PCB
removed the USB programmer (connected externally once then OTA)
Delay power up circuit: data sheet example is 10k and 0.1u with tau=0.001s to use same resistor multiple times, changed to 20k

Goal: power by typical outdoor power supply
googled around and found Texas Instruments LM2596SX
they have a tool here to design circuit
- https://webench.ti.com/power-designer
Selected Parameters
- Input 12V - 25V
- Output 5V at 0.8A (0.8A because for higher currents I couldn't find the suggested components on JLCPCB)
- Temp 30
From the tool selected components that JLCPB offers
- Input Cin: UUD1H221MNL1GS (Nichicon)
- Diode D1: SS26FL (Fairchild Semiconductors)
- Inductor: SLF12575T-151M1R5-PF (TDK)
- Outout Cout: 2x TPSA105K035R3000 (AVX)
Open Questions
- ESP32 datasheet mentions 0.5A, so 0.8A design should be enough?
- to be safe I convert from 24V -> 5V using switching power supply and later 5V -> 3.3V using linear regulator that way I can also optionally connect 5V USB is it better to directly go to 3.3V ?