I have an Arduino Uno and I want to connect;
- RFID Reader (RC522)
- WiFi Module (ESP8266 ESP-01)
- SD Card Module
- RTC (Real Time Clock - DS1307)
Same time but pinouts are not enough. Is there a way to doing this with Uno or I have to buy an Arduino Mega ? I saw "Expansion Sensor Shield"s but I do not know what is the logic of using this ?