I need a little help on my first pcb

[filfil]

I am making a weather station, and I don't understand why the i2c doesn't work on the pcb but used to work when i was testing on breadboard. There is bmp180 and lcd connected to i2c and the board doesn't see any devices.

[Sprite]

Please post your schematics and code and tell us exactly what boards the BMP180 and LCD are on; we can't really do much with only an unannotated PCB.

[mikemoy]

Where are your I2C pullup resistors ?

[ahsrabrifat]

On breadboards, breakout modules often have built-in pull-up resistors on SDA and SCL. Your PCB may lack pull-ups, resulting in the I2C bus not working.Add 4.7kΩ or 10kΩ pull-up resistors from SDA and SCL to VCC (typically 3.3V or 5V).Look at your schematic/layout: Do you see resistors pulling up the I2C lines?
Your SDA and SCL traces appear to be routed, but verify continuity.

Use a multimeter in continuity mode to check:

MCU SDA → BMP180 SDA

MCU SCL → BMP180 SCL

MCU SDA/SCL → LCD SDA/SCL

Here is also a compact design of a weather station. You can see the PCB for further idea. https://www.pcbway.com/project/sharepro ... e923c.html