0

I have an ACS712 (5v sensor), an ADS1115 (5 or 3.3v) and an ESP8266 board (3.3v).

I know I can't directly use the ACS with the ESP without a voltage divider on the analog pin. So I figured I could run the ADS and the ACS off 5 volts as the ADS communicates over I2C. Does this cause any issues with the SDA/SCL lines on the ESP?

What is the correct way in going about this?

asked Oct 7, 2019 at 20:41
2
  • The I2C lines of of ADS1115 will use 3.3 V if you power it with 3.3 V, but then the maximum analog input voltage would be 3.6 V (VDD + 0.3 V). Commented Oct 8, 2019 at 5:09
  • i am aware, but that wasn't my question Commented Oct 8, 2019 at 5:18

1 Answer 1

2

The SDA line of of ADS1115 will use 3.3 V if you power it with 3.3 V, but then the maximum analog input voltage would be 3.6 V (VDD + 0.3 V).

The ACS712 has the middle value at 2,5 V so to read it you need the 5 V range and must power the ADS1115 from 5 V. Then the SDA line of esp8266 will be connected to 5 V logic level, but the esp8266 pins can handle 5 V TTL communication currents.

The SCL line is driven from master (esp8266) at 3.3 V and the ADS1115 is good with it.

answered Oct 8, 2019 at 5:41

Your Answer

Draft saved
Draft discarded

Sign up or log in

Sign up using Google
Sign up using Email and Password

Post as a guest

Required, but never shown

Post as a guest

Required, but never shown

By clicking "Post Your Answer", you agree to our terms of service and acknowledge you have read our privacy policy.

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.