Stemma QT PCF8574 GPIO Expander #comingsoon

The PCF8574 is an ultra-low-cost I2C GPIO expander that works with 3-5V logic, lets turn it into a lil Stemma QT breakout for adding 8 I/O pins for only a few bucks! There’s 3 address jumpers on the back so you can have up to 8 of these on one bus.

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1 Comment

  1. IMO the MCP23017 is a much better I2C GPIO expander-thingy:

    28PDIP $2.95 ea.

    Mouser has 9,960 28PDIP MCP23017s in stock at my post time, qty.-1 @ $1.32 ea., qty.-100 @ $1.00 ea. Prices for more than 100 are not listed, so Mouser might be rationing what they have left to deter scalpers. Mouser has just 133 28SSOP MCP23017s in stock and the lead times are long to really long for anything else. Digi-Key is down to just 1,070 28PDIP and 555 28SOIC in stock, all other variants are ZERO stock. But surely by now there must be many Chinese clones available – right?. Maybe not, LCSC is showing just 1,162 28SOIC in stock, all other variants are ZERO stock including the 28PDIP, which is weird. Also, LCSC’s prices are quite high.

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