CJMCU-09 I/O Expansion Module - GPIO Voltage Level Shifter With LED Driver & Keypad Scanner

About This Product

Hey makers and tinkerers, this CJMCU-09 module is seriously handy when you're running out of GPIO pins on your microcontroller. It gives you 16 extra channels of GPIO through I2C interface - which is pretty awesome when you think about it. But wait, there's more - it also has a programmable LED driver and a keypad scanning engine that can handle up to a decent-sized keypad matrix. The voltage level shifting capability is super useful too - it works between 1.2V and 3.6V and is 5.5V tolerant, so you can interface different voltage devices without worrying about frying anything. The board measures 36x25x3mm, so it's compact enough for most projects without being tiny and hard to work with. They've even created a library to get you started, which saves so much time compared to writing everything from scratch. The red PCB is nice quality with clear silkscreen labeling. Perfect for Arduino projects, Raspberry Pi setups, or any embedded system where you need more I/O than your main board provides. The keypad scanning feature alone makes it worth it if you're building any kind of interface with buttons. The LED driver means you can control multiple LEDs efficiently without using up all your microcontroller resources. It comes with the pin header too, so you can solder it in whatever orientation works for your project. Seriously, if you've ever been in the middle of a project and realized you're out of pins, this little module will save your bacon. The documentation is decent, and there's good community support online too.