Water Level Sensor - always > 40%

Hey hey,

by now I have two Grove Water Level Sensors, both showing the same behaviour. Whenever I turn them on, they start of with a base level of 40% - when I put them in water the level rises, but it never goes lower than 40%.

The code is exactly the code from the linked example page. However, it still does not go lower.

When looking at the logs for the high and the low values, there is a peculiarity … the low value never changes.

[18:48:43][D][custom:033]: low 8 sections value =
[18:48:43][D][custom:035]: high 12 sections value =

Does anyone have a clue when this will happen? If the cable would be wrong, the I2C bus protocol would probably show no data at all, correct?
I also tried with both 3V and 5V, just no changes. It is also not the sensor, as I now tried two of them.

Anyone having an idea?


I know this is an old thread but, how did you get two of these communicating. Did you use these with a multiplexer, i’m struggling with my code to have them reading from the multiplexer.

i assume he is saying he has two and switched ine for the other and gets the same results… that sounds like a code problem to me

interesting device, i didnt know it was so complicated

Hi klassm, it sounds like something went wrong with the program. You are right, if there is an error in the I2C protocol, the sensor cannot read the data, 3.3V/5V are his standard working input voltage, so the reasons for the error may be due to two reasons:

  1. Program errors, the problem is simple, you can view the wiki Seeed, in this you can see the detailed wiring and various parameters of the module description: Grove - Water Level Sensor | Seeed Studio Wiki

  2. The sensor itself may be damaged, if the above can not solve your problem, you can try to send back, we will repair your sensor!