Because the Arduino (and Basic Stamp) are 5V devices, and most modern sensors, displays, flash cards and modes are 3.3V-only, many makers find that they need to perform level shifting/conversion to protect the 3.3V device from 5V. We do have some other handy level shifters in the shop, from the DIP 74LVC245 to the fancy bi-directional TXB0108. However, neither of these are happy to work with I2C, which uses a funky pull-up system to transfer...

Because the Arduino (and Basic Stamp) are 5V devices, and most modern sensors, displays, flash cards and modes are 3.3V-only, many makers find that they need to perform level shifting/conversion to protect the 3.3V device from 5V. Although one can use resistors to make a divider, for high speed transfers, the resistors can add a lot of slew and cause havoc that is tough to debug. For that reason, we like using 4050/74LVX245 series and similar...

Level shifting chips let you connect 3V and 5V devices together safely. This chip is similar to others in the shop (such as the 74LVC125) except this one is particularly good at converting 3V logic up to 5V . This is in demand especially when connecting some 3V devices such as the Teensy 3 to NeoPixels! Just power the 74AHCT125 with 5V, it will detect 3V logic properly. You can also use it to connect 5V logic out to 3V logic in, that's when...

You just found the perfect I2C sensor, and you want to wire up two or three or more of them to your Arduino when you realize "Uh oh, this chip has a fixed I2C address, and from what I know about I2C, you cannot have two devices with the same address on the same SDA/SCL pins!" Are you out of luck? You would be, if you didn't have this ultra-cool TCA9548A 1-to-8 I2C multiplexer ! Finally, a way to get up to 8 same-address I2C devices...

Because the Arduino (and Basic Stamp) are 5V devices, and most modern sensors, displays, flash cards and modes are 3.3V-only, many makers find that they need to perform level shifting/conversion to protect the 3.3V device from 5V. Although one can use resistors to make a divider, for high speed transfers, the resistors can add a lot of slew and cause havoc that is tough to debug. For that reason, we like using 4050/74LVX245 series and similar...

Most of our customers love using the Arduino for prototyping, design and invention but find themselves stuck when trying to connect the Arduino to the latest sensors, displays, controllers, interfaces, etc. as they are almost all 3.3V logic these days. We try to solve this problem by having all our breakout boards be 5V compatible or when that's not possible, including a level shifter chip but there are still thousands of tempting devices...