This tutorial of Robo India explains how to a transistor as a switch on NodeMCU using Arduino IDE.
Detailed Tutorial
1. Introduction:
A very less current consuming device like LEDs can be controlled directly through an Node MCU. Other devices can be controlled by an Node MCU signal using a transistor. In such case a transistor is there between an Node MCU and the device. The transistor takes signals from the Node MCU and controls the device as per the signals. This chapter deals in using an NPN transistor as a switch.
1.3 Hardware required
S.No. | Item | Quantity |
| 1 | NodeMCU | 1 |
| 2 | Breadboard | 1 |
| 3 | LED | 1 |
| 4 | Resistor 1k | 2 |
| 5 | Jumper Male to male | 6 |
| 6 | nPn Transistor | 1 |
2. Building Circuit
Schematic of circuit.
Layout of circuit
3. Programming:
Once the circuit part is done, NodeMCU is needed to be programmed. Here is the code to run this circuit on NodeMCU.
You may download this code (Arduino Sketch) from here.
// Robo India Tutorial
// Digital Input and Output on LED
// Hardware: NodeMCU
const int transistor = 4; // Assigning name to Trasistor
void setup() {
pinMode(transistor, OUTPUT); // Assigning pin as output
}
void loop() {
digitalWrite(transistor, HIGH); // making pin high
delay(1000);
digitalWrite(transistor, LOW); // making pin low
delay(1000);
}
4. Output
The LED blinks at a time interval of 1 second.
5. Troubleshooting
LED is not blinking: Check polarity of the LED and the transistor as shown in the circuit.
If you have any query please write us at support@roboindia.com
Thanks and Regards
Content Development Team
Robo India
https://roboindia.com