아두이노 - 라즈베리 i2c 연결

라즈베리는 3.3v 일테고

아두이노는 5v 일텐데.. 그냥 연결해도 되려나?

라즈베리 날려먹긴 싫은데.. 레벨 시프터 사야하나 ㅠㅠ

[링크 : https://www.eleparts.co.kr/EPX8MXNR] 6천원... ㅠㅠ

일단은...

아래는 3.3V 짜리를 5V인 아두이노에서 쓰는거지만...

[링크 : http://playground.arduino.cc/Main/I2CBi-directionalLevelShifter]

2016/04/01 - [embeded/arduino(genuino)] - 아두이노 level shift / MPU-6050

The Raspberry Pi is running at 3.3 Volts while the Arduino is running at 5 Volts. There are tutorials suggest using a level converter for the I2C communication. This is NOT needed if the Raspberry Pi is running as “master” and the Arduino is running as “slave”.

The reason it works is because the Arduino does not have any pull-ups resistors installed, but the P1 header on the Raspberry Pi has 1k8 ohms resistors to the 3.3 volts power rail. Data is transmitted by pulling the lines to 0v, for a “high” logic signal. For “low” logic signal, it’s pulled up to the supply rail voltage level. Because there is no pull-up resistors in the Arduino and because 3.3 volts is within the “low” logic level range for the Arduino everything works as it should.

[링크 : http://blog.oscarliang.net/raspberry-pi-arduino-connected-i2c/]

    [링크 : http://dsscircuits.com/articles/effects-of-varying-i2c-pull-up-resistors]

[링크 : http://blog.retep.org/2014/02/15/connecting-an-arduino-to-a-raspberry-pi-using-i2c/]

걍.. 과감하게(?) atmega 녀석들이 대부분 2.8V~5.5V 니까 3.3V로 주면 안되려나?

Operating Voltage:

1.8 - 5.5V

TWI(I2C)쪽 입력 전압은 Vcc + 0.5 니까.. 3.3V 주면은.. 어떻게 안되려나?

그나저나.. 0.3V~0.7V 로 무지 좁네..

[링크 : http://www.atmel.com/...atmega48a-48pa-88a-88pa-168a-168pa-328-328p_datasheet_complete.pdf]