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I²C

Emlid Neutis has 4x I2C interfaces:

Port Device SCK Pin SDA Pin Pull-Up
I2C0 /dev/i2c-0 PA11 PA12 Yes
I2C1 /dev/i2c-1 PA18 PA19 No
I2C2 /dev/i2c-2 PE12 PE13 Yes
S_I2C /dev/i2c-3 PL0 PL1 Yes

In this example, we connect an I2C device (a breakout board that includes MS5611 pressure sensor) and detect it.

Attaching board

ms5611_neutis

Connect SDA and SCK directly to the PA12 and PA11 pins. Provide the power to your board and connect to the GND.

Board Neutis Purpose
VCC 5V_IN Power
GND GND Ground
SCL PA11 I2C clock
SDA PA12 I2C data

Detecting sensor

1) Try to detect I2C adapter:

i2cdetect -y 0
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: 60 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- 77

MS5611 usually can be found at the address of 0x77, but when the CSB pin (Chip Select which is used to enable/disable the interface) is pulled high, the address may change to 0x76.