Add another 16 pins to your microcontroller using a MCP23017 port expander. The MCP23017 uses two i2c pins (these can be shared with other i2c devices), and in exchange gives you 16 general purpose pins. You can set each of 16 pins to be input, output, or input with a pullup. There’s even the ability to get an interrupt via an external pin when any of the inputs change so you don’t have to keep polling the chip.
Use this chip from 2.7-5.5V (good for any 3.3V or 5V setup), and you can sink/source up to 20mA from any of the I/O pins so this will work for LEDs and such. Team it up with a high-power MOSFET if you need more juice. DIP package means it will plug into any breadboard or perfboard.
You can set the i2c address by tying the ADDR0-2 pins to power or ground, for up to 8 unique addresses. That means 8 chips can share a single i2c bus – that’s 128 I/O pins!
We used this chip in our RGB LCD + Keypad shield to both control an LCD and read a 5-way keypad and found it to be very reliable and easy to get up and running. We even have an Arduino library with example code written which will set pin state, read and write from individual pins, and set the pullups.
Fast Shipping and Professional Packing
We offer a broad range of shipping options due to our long-standing partnerships with UPS, FedEx and DHL. Our warehouse staff is highly trained and will pack the goods according to our precise and exact specifications. Before shipping, all goods will be thoroughly examined and securely secured. We deliver to hundreds of thousands of customers every day in different countries. The fact that we are determined to become the largest online retailer in the world is evident. Warehouses and distribution centres can be located in Europe as well as the USA.
Note: Orders with more than one item will be assigned a separate processing time for each item.
Before shipment, all ordered items will be thoroughly examined. Most orders are now shipped within 48 hrs. Delivery is expected to take between 3 and seven days.
Returns
Stock is dynamic, and cannot be fully controlled by us because of the involvement of multiple parties including the factory and our warehouse. This means that the actual stock could alter at any time. It's possible that the stocks could be depleted after your order has been processed.
The policy is for 30 days. Unfortunately, if 30 days have passed from the date you purchased the item, we will not be able to provide a refund or exchange.
The item must not be in use and must be in the original packaging. You must have the item in the original packaging.
Related products
Components & Parts
Components & Parts
Components & Parts
0.1″ 36-pin Strip Right-Angle Female/Socket Header (5 pack) Adafruit
Components & Parts
Components & Parts
Components & Parts
16mm Illuminated Pushbutton – White Latching On/Off Switch Adafruit
Components & Parts
Components & Parts
Components & Parts
Components & Parts
Components & Parts
Components & Parts
Components & Parts
5.0V 250mA Linear Voltage Regulator – L4931-5.0 TO-92 Adafruit
Components & Parts
16mm Illuminated Pushbutton – Blue Latching On/Off Switch Adafruit
Components & Parts
3.5mm (1/8″) 4-Pole (TRRS) Audio Plug Terminal Block Adafruit
Components & Parts
Components & Parts
Components & Parts
Components & Parts
Components & Parts
Components & Parts
16mm Illuminated Pushbutton – Yellow Latching On/Off Switch Adafruit
Components & Parts
Components & Parts
Components & Parts
Components & Parts
Components & Parts
Components & Parts
Components & Parts
Components & Parts
Components & Parts
Components & Parts
16mm Illuminated Pushbutton – Green Latching On/Off Switch Adafruit
Components & Parts