Having issues with the Grove barometer sensor

Hello everyone, I'm currently working on a project where I need to implement a weather station with LoRa technology.

In order to complete this I need to use a Grove barometer sensor, and also a LoRa shield (Mbed - SX1272MB2xAS)

I used the library I found on seeed studio (Barometer_sensor.zip) to make this sensor work properly with the Grove shield, and there was no problem... Until I plugged the LoRa Shield. After that, the sensor wouldn't initialize properly.

When the LoRa shield isn't plugged in, I see in the console : "Temperaturet: Temperaturet2:" which (I believe) means that the sensor is initializing correctly. Once I've plugged the LoRa shield in, I only see "Temperaturet" then nothing, and the program seems to be in an infinite loop or something, but it doesn't initialize anyways...

I can provide further information if needed...

It would help if you provide links to all hardware and software involved.

On which type of Arduino do you use that combination? Do you connect the Grove sensor to the mbed shield?

It doesn't change a thing if I connect the sensor to the mbed SX1272MB2xAS LoRa shield, or if I connect it to the BaseShield (by seeed studio). As long as the LoRa shield is connected too, the sensor doesn't work properly.

I'm using an Arduino Uno, I have the BaseShield v2.0 by Seeed Studio, the SX1272MB2xAS mbed shield for LoRa and my Grove barometer sensor.

The problem comes from the mbed shield since my sensor works correctly as long as I don't connect the mbed LoRa shield to the microcontroller.

I still can't manage to understand how that is possible and I can't get it to work properly

It seems to be very hard to provide links to that damned hardware. You have to provide that information, I don't like to search for the stuff every time I read that topic!

You do know that the LoRa shield is designed for 3V3 and not for the 5V of an UNO, don't you? The specification says it has mbed compatible connectors which seems to have the same physical extents as the Arduino shield interface but seems to be 3V3 only. Shields that are Arduino compatible must be at least 5V tolerant which doesn't seem to be the case here.

The next problem is that the shield has pull-ups for the I2C interface to 3V3 (R1 and R2). These don't make sense, I would desolder them. The resulting resistor is below 2k, which is inside the specs.

Do you have an original Arduino UNO or a clone? The original UNO provides 3V3 power up to 50mA, the LoRa shield might go will above that. Most clones have weaker voltage regulators on board.