It’s rare to see breadboard friendly I2C sensors, but this TO-220 package with 5 pins is, in fact, such a thing! It’s a basic temperature sensor, not the highest precision in the world, only ±2°C but it will get the job done when you need simple temperature logging or monitoring.
Wiring it up is easy, pin 2 is SDA, middle pin is GND, pin 4 is SCL and the rightmost pin 5 is VDD. You can power it with 3.3 or 5V logic so it’s good for any microcontroller or microcomputer. Note you will need to add I2C pull-ups on your breadboard especially if your I2C controller does not have them built in already
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.
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I have found that the TC74A is not completely I2C compatible, and you may have trouble using it with some processors. The I2C specification requires a data hold time for I2C devices of 0 ns, but the TC74A datasheet specifies a minimum hold time of 1250 ns. If a microcontroller has an I2C interface that is designed to operate up to 1 MHz (Fast-mode Plus) then a hold time of 1250 ns is longer than the SCLK period, so it doesn’t surprise me that a fast microcontroller would provide a data hold time much, much less than 1250 ns.
I have found that the TC74A is not completely I2C compatible, and you may have trouble using it with some processors. The I2C specification requires a data hold time for I2C devices of 0 ns, but the TC74A datasheet specifies a minimum hold time of 1250 ns. If a microcontroller has an I2C interface that is designed to operate up to 1 MHz (Fast-mode Plus) then a hold time of 1250 ns is longer than the SCLK period, so it doesn’t surprise me that a fast microcontroller would provide a data hold time much, much less than 1250 ns.