Electronics — Common ICs and Modules Quick Reference
electronicsicmodulereferencerelaymosfetlevel shifterl293d1c3d
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Electronics — Common ICs and Modules Quick Reference
BSS138 Level Shifter (3.3V to 5V)
| Pin | Function |
|---|---|
| LV | 3.3V reference |
| HV | 5V reference |
| GND | Ground |
| LV1-4 | Low voltage signals |
| HV1-4 | High voltage signals |
Bidirectional — no need to specify direction.
Relay Module (SRD-05VDC)
| Pin | Function |
|---|---|
| VCC | 5V (coil power) |
| GND | Ground |
| IN | Signal — active LOW |
| NO | Normally Open |
| NC | Normally Closed |
| COM | Common |
Active LOW: send LOW to trigger relay. Max: 10A 250VAC.
L293D Motor Driver
| Pins | Function |
|---|---|
| 1, 9 | Enable A, B (PWM speed) |
| 2, 7 | Input 1A, 2A (direction A) |
| 3, 6 | Output 1A, 2A (to motor A) |
| 8 | Vmotor (up to 36V) |
| 16 | Vcc (5V logic) |
Direction: IN1=HIGH, IN2=LOW = forward. IN1=LOW, IN2=HIGH = reverse.
IRF520 MOSFET Module
| Pin | Function |
|---|---|
| SIG | Gate — MCU signal |
| GND | Ground (MCU + load) |
| Screw + | Positive load |
| Screw - | Negative load + GND |
Drives up to 9A DC from 3.3V or 5V signal.
I2C OLED SSD1306
| Pin | Function |
|---|---|
| VCC | 3.3V or 5V |
| GND | Ground |
| SCL | I2C clock |
| SDA | I2C data |
Default I2C address: 0x3C
DHT22 Temperature and Humidity
| Pin | Function |
|---|---|
| VCC | 3.3-5V |
| DATA | Single-wire (10k pull-up to VCC) |
| GND | Ground |
DHT22: ±0.5C, 0-100% RH, 0.5Hz update rate