- This topic has 4 replies, 3 voices, and was last updated 2 years, 2 months ago by .
- You must be logged in to reply to this topic.
Home › Forums › The libraries hosted on the site › PCF8574 i2c digital I/O expander › PCF8574-transistor base switch
Tagged: Arduino, npn, pcf8574, transistor
Hi @xreef,
Thank you for this great library and all the effort you did.
I am having difficulties to drive a transistor using the PCF8574 GPIO as a basic switch. My objective is to turn on and off audio lines using the bjt driven by the expender.
I would like to request for sample/example schematic or circuit you use to connect a transistor to the expander.
Thank you in advance
Hi tsctrl,
here a schema with a simple npn transistor to light a led.
Bye Renzo
Hi, this works fine with an LED but I’m having trouble driving a 12V motor using the npn as a switch to complete the ground. Any idea why this would happen?
Hi Celeb10,
I think the transistor isn’t sufficient to control a 12v motor, you need more ampere, try to use a MOSFET.
Bye Renzo
thanks Bye Renzo
More
3D Printer 3D printer upgrade ABB Arduino Arduino IDE Arduino SAMD boards Aurora AWS CNC Cyclone PCB Factory Cyclone PCB Factory how to build It Display E32 E70 esp01 esp32 esp8266 File System Firmware i2c Library LoRa MicroPython Milling PCB My PCB Networking PCB pinout Power saving Programming board Raspberry Pi REST API RF rp2040 SD Card Sensors Sleep and Wake UP SPI STM32 Storage devices Temperature Tutorial Web Server Wemos D1 mini WiFi