Arduino Uno Multiple Modules

Question

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 ?

Regards

• Milliways: It depends. You need to provide more detail. Some of the devices use I²C which can share connections provided they have different addresses. Others use SPI which need individual select pins.

Answer 1

Let's see which device uses which communication protocol:

1. WiFi Module (ESP8266 ESP-01) uses Serial communication.
2. RTC (Real Time Clock - DS1307) uses I2C communication.
3. RFID Reader (RC522) uses SPI communication.
4. SD Card Module also uses SPI communication.

Now, the Arduino UNO supports One I2C, One SPI and One Serial (by default) communication port.

So, you can easily connect your Wifi and RTC modules.

Now, actual problem is: "How to access multiple SPI interfaces on Arduino" (and that is a solved problem).

Hope it helps and you don't have to buy an Arduino MEGA.