Pin and connectors

Analog input (pins 34, 35, 36, 39)
Digital input  (pins 27, 32)

Really on board 2   (pins 15, 12)
Buzzer pin (0)
ESP32 Reset default settings  pin(2)
IR pin(3)

Serieal connector  4pin (+5v, 4, 25, GND) 
Modbus Serieal connector  4pin (GND, 16, 17, +5V) 
Display 1.3” 4pin (+3v, GND, 22_CL, 21_DA)
CRT connector  5pin  (+3v, 21_D, 22_C, NC, GND)
GSM 6pin (RF, +4V, RS_33, RX_14, TX_13, GND)
Ethernet connectors 2x6pin (5, 18, 19, 23, 26)

Modules & components 

ESP32 D1

SIM800 GSM

ETHERNET W5500

CRT 

DISPLAY OLED 1.3″

RS485 MODBUS 

RELAY 5V 5A

EEPROM

BUZZER

CASE DIN RAIL

ESP 32 software

GENERAL

GSM

TRIGGER LINK

TIMERS

SENSORS

IR

MODBAS

IP

BUTTONS

CHARTS

APP