Adding I/O with MCP23017 - Collin’s Lab Notes #adafruit #collinslabnotes

Don’t want to switch boards for more I/O? Add many many pins with an I2C port expander #adafruit #collinslabnotes
Upgrade with port expanders:

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[mattb]

FYI the MCP23018 is the newer version of this part. There's also an 8bit gpio expander version the mcp23008 (with a newer version of that being the mcp23009). the newer versions have slightly fewer pins by using a voltage divider to set the address pin (which has its pros and cons). otherwise, the newer versions are identical.

[jimwithheld]

I love these quick 1-minute Lab Notes. Lots of cool ideas, hints and reminders on various stuff. Thank You.

[linux]

The RP2040 has two i2c buses, so 256 i2c pins are possible there. There is also the MCP23S17 using the SPI bus for even more expansion.

[LordPhobos]

I ❤❤❤❤❤ this chip 😊
It has made so many projects so much easier to build - a lotbof projects that would have otherwise needed a mega just for the I/O got simplified with a couple of these, and a nano 👍❤

[Orionrobots]

Another favourite chip for output multiplexing is the pca9685, for multiple pwm outputs, for controlling (through power drivers) many motors or leds.

[deltaray]

Depending what you're doing, you can also use a shift register, which is probably cheaper and easier for many tasks.

[joshm]

Interesting way to add ports, I was guessing you were going to use some sort of shift register

[herbertattema]

I just use the shift register for gpio expension

[merterenkarabulut]

Actually you don't even need to use i2c. Simply use a shift register ic and you are good to go. Its older tech but does the same job for cheap.

[furkanayas]

After the 128 pins, using demux for 2^128 hdjssj

[bharattamang]

How is it different from using a multiplexer?

[juanfra]

Question where you can get the library for example for a pic

[EvilDaveCanada]

Could this port expander be used on the chip must used when making a DIY Mechanical keyboard ??

[hanshearth]

What about Analog Pins? I want to expand the number of analog pins to have multiple joysticks/pots. Is there something like this chip? Or do I need a multiplexer?

[gdawgpwnsall]

Iirc the i2c version is only 15 bits. I made that mistake with my work board.

[trayvordemonslayer]

I just stumbled on this content creator, I don't really understand much, what is a good way to dive into learning this stuff?

[deviousengineer]

What’s the advantage of this over shift registers?

[rushikeshpawar]

Any one give the code used in this Shorts for mcp23017

[Shiznit]

I use a mega2560 arduino and nearly all the pins are in use for engine management

[KnOwThEDiNo]

Thankgod u said its a lot I was all lost before that