common I2C devices address
// I2C device found at address 0x40 ! // INA219, INA226
for IOD1001-dat
for ESP32-CAM-dat //I2C device found at address 0x3C ! // OLED = 0x78 //I2C device found at address 0x75 ! // IP5306 //I2C device found at address 0x76 ! // BME280
// I2C device found at address 0x1F ! // KX023 // I2C device found at address 0x38 ! // AHT20
tech
Boards
Set custom I2C
Wire.begin(I2C_SDA, I2C_SCL);
testing scan I2C Wire.begin(4,13); Wire.begin(2, 3);
I2C usage in Micropython
-
from machine import I2C, Pin
Define I2C on GPIO 15 (SDA) and GPIO 13 (SCL)
i2c = I2C(0, scl=Pin(13), sda=Pin(15), freq=400000) i2c = I2C(0, scl=Pin(13), sda=Pin(15), freq=100000)
print("I2C scan:", i2c.scan())
command line readout
Command Line Readout
With the included i2cdump and i2cget tools it is possible to read data out from a shell. The dump reads a range of bytes, here again
with -y to disable interactive confirmation, range 0x02-0x2d for the standard registers,
bus 0 and address 0x55. W for 16 bit words, because the chip returns directly 2 bytes, no need to send request for every single address.
orangepipc2:~:# i2cdump -y -r 0x02-0x2d 0 0x55 W
0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef
00: 00 00 ff ff 71 0b 66 0f 80 01 13 06 27 09 ....q?f???????
10: 02 05 16 08 00 00 ff ff ff ff ff ff ff ff 8a f8 ????..........??
20: 28 00 46 12 00 00 ff ff 6f 0b c0 03 3e 00 (.F?....o???>.
orangepipc2:~:# i2cget -y 0 0x55 0x08 w
0x0f66
orangepipc2:~:# i2cget -y 0 0x55 0x2c w
0x003ecode library
the most easy to use library for ESP
circuits
- common pullup resistors 1K/4.7K/10K
RPI-I2C
GPIO2 and GPIO3
setup for RPI I2C
Driver Installing
1.Enable Raspberry Pi I2C. Skip this step if it is already enabled. Open terminal and input the following commands and press "Enter":
pi@raspberrypi:~ $ sudo raspi-config
Then use the UP/Down keys to select "5 Interfacing Options", press Enter, select "P5 I2C" and press Enter to comfirm "Yes". Restart the Raspeberry Pi board.
2.To install Python dependency library and git, the Raspberry Pi needs to be networked. Skip this step if already installed. In the terminal, input the following commands and press Enter:
pi@raspberrypi:~ $ sudo apt-get update pi@raspberrypi:~ $ sudo apt-get install build-essential python-dev python-smbus git
3.Download the DFRobot_CH423 driver library. In the terminal, type the following commands and press Enter:
pi@raspberrypi:~ $ cd Desktop/ `pi@raspberrypi:~/Desktop $ git clone https://github.com/DFRobot/DFRobot_CH423
I2C scan in RPI
install scan
sudo apt-get install -y i2c-tools
scan i2cdetect -y 1
test
Write data to the PCM5122 registers (replace 0x4C with the correct I2C address):
i2cset -y 1 0x4C <register> <value>
Read data from the PCM5122:
i2cget -y 1 0x4C <register>
code
initiate check
while(!bme.begin())
{
Serial.println("Could not find BME280 sensor!");
delay(1000);
}
custom I2C address
// Initialize the sensor with the custom I2C address (0x76 or 0x77)
if (!bmp280.begin(0x76)) // Use 0x76 or 0x77 depending on your sensor's address
{
Serial.println("Could not find BMP280 sensor!");
delay(1000);
}
pin arrangement
SDA
- SCL
- GND
- +5V