Barometric sensor MS5803-14BA is not Showing up on I2cdetect

Sensors Environmental
1

I am trying to connect a barometric pressure sensor MS5803-14BA with raspberry pi 3B+ in i2c but it is not showing up on i2cdetect.

Connection is straightforward. I connected it as following,

SDA to SDA of Raspberry

SCL to Scl of raspberry

3.3v to 3.3v of Rsapberry

Gnd to Gnd pin of raspberry

I checked it on arduino and it is working fine but it doesn’t show up on i2c bus on raspberry pi 3b+.

Please help. Thanks.

2

Hi latpate.aniket92,

Double check to make sure you have enabled the I2C bus in your Configuration settings on the Pi. It is not enabled by default on the standard distro of NOOBs or Raspbian. [This section of our Raspberry Pi SPI and I2C Tutorial goes over how to do that.](Raspberry Pi SPI and I2C Tutorial - SparkFun Learn)

3

Hi thanks for the response. I used LLC-I2C click (a 5v to 3.3v level shifter from Microelctronoca) as i wanted to power the sensor with 5v power supply. Now it is showing up on i2cdetect on adress 0x76 but still hitting an error.

Error is :

(IOError errno 121 remote i/o error raspberry pi).

4

That error usually means Python cannot talk to the device. Since it is showing up with ‘sudo i2cdetect’, there’s not a hardware issue. Also, a level shifter is not really necessary here since I2C is [open-drain. Unless you have other I2C devices on the bus that run at different logic levels than the MS5803-14BA, the logic of the master device on the I2C bus is irrelevant since it only pulls the lines LOW to communicate. Level shifters are not the proper way to power a device like this with a higher voltage as they convert the signals, not the power rails. The MS5803-14BA has a maximum input voltage of 3.6V so make sure you do not power it with anything higher than that.

Most likely, the problem is with the Python script you are trying to use with the MS5803. Unfortunately, we do not have Python script available for this breakout and cannot help debug custom or code you found to use with this sensor.](https://learn.sparkfun.com/tutorials/i2c)

5

Hi, thanks for the suggestion. I tried different things turned out that this pressure sensor is very sensitive to voltage (does not work well with little change in voltage). The wires I added was acting as a resistance and creating an imbalance in supply. So, I reduced the length of wire and connected it to raspberry pi 3v3 and it is working fine. Thanks for the help.