BH 1750 Lux Sensor

Projects General Guidance
1

Hi.

I have my standard Weather Station (Temp, Hum & Air Press) up and running with a UNO R3. I would now like to add a BH 1750 LUX sensor to the station. Has anyone had experience of installing one of these? they are obviously not water proof, and they need to be exposed to the light, will they work properly in say a sealed glass jar?

2

Google for the data sheet and post the link.

3
4

How will you make electrical connections when it is sealed in a glass jar?
Paul

5

When You've solved the issue indicated by Paul_KD7HB Know that this device, according to the data sheet, is a 3.3 volt device, and the UNO is a 5 volt device. Level shifters are needed.

6

Hi, firstly the UNO has a 3.3 volt pin, I would use a glass jar with a sealed metal lid, like a preserve jar, drill a hole in the lid and pass the wires through the hole onto the sensor, the hole can then be sealed with silicone, and the jar will be upside down ie the lid will be underneath, but can I use a glass jar which was my original question?

7

That 3.3 UNO pin can maybe supply the sensor with proper Vcc, yes. How will You connect the signal lines between mismatched logic type chips? There the level shifter is needed for the signals from the UNO to the sensor.

8

If you use stranded wire, it is no longer sealed! Air and moisture will move through the wire strands and into the jar. Changes in temperature from day to night and back will pump the air and moisture.
Paul

1 Like
9

You could try it. My concerns would be that it would get hot and that the glass won't be fully transparent so the readings would be lower by some margin. Testing would tell you whether either problem is significant.

10

I think you will have issues with a sealed glass jar. Under certain conditions the moisture you will have sealed in the jar will condense on the inside of the jar.

Perhaps if you added an sufficient desiccant (or rice) you might be able to collect the moisture and not have it condense.

I had a project in mind that would use this part with a BME280. I figured I would put it in a small glass jar with the opening down. Wires out the bottom with a drip loop. I was also planning on spraying the BH1750 board with an silicone conformal coat, masking off the tiny window of the sensor.

11

May thanks to you all, looks like I have some experimenting to do.

Regards
Ray

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