Pullup with logger shield
Moderators: adafruit_support_bill, adafruit
Please be positive and constructive with your questions and comments.
- spiney
- Posts: 214
- Joined: Mon Jul 09, 2012 6:35 am
Pullup with logger shield
The logger shield with RTC uses I2C, I believe. The documentation does not mention pullup resistors, but other I2C sensors need pullups to either 3.3 or 5Volts. So my worry is that there may be internal pullups to 5v to enable the shield to work and that may harm 3.3V sensors.
- adafruit_support_bill
- Posts: 88093
- Joined: Sat Feb 07, 2009 10:11 am
Re: Pullup with logger shield
Yes, there are 5v pullups on SDA and SCL. For 3.3v sensors, an i2c-safe level shifter should be used: http://www.adafruit.com/products/757
Another alternative is to remove the pullups (r1 & r2) and install pullups from the SDA & SCL breakout holes to 3.3v.
Another alternative is to remove the pullups (r1 & r2) and install pullups from the SDA & SCL breakout holes to 3.3v.
Please be positive and constructive with your questions and comments.