Hi everyone, I wanted to share my recent success in extracting the battery level from an MQTT message. I’ve been working on integrating my tablet into OpenHAB, and while most channels worked smoothly, the battery level was proving to be a bit tricky. Let me walk you through my journey and the solution I found!
Initially, I set up a generic MQTT Thing for my tablet and created channels for various data points. Most of them worked without issues, but the battery level kept giving me a headache. The MQTT message structure was clear, but I couldn’t get the number to display correctly in OpenHAB.
After some research, I realized that the issue was with how I was transforming the incoming MQTT message. I was using JSONPATH to extract the battery level, but it wasn’t working as expected. I decided to take a closer look at the message structure and found that the battery level was nested under a specific key. Once I adjusted my JSONPATH query to target that key directly, everything fell into place!
Here’s the step-by-step solution I found:
- Identify the correct JSONPATH query: Use the MQTT message structure to pinpoint the exact location of the battery level. In my case, the correct query was
$.batteryLevel. - Update the channel configuration: Modify the channel in your
.itemsfile to use the correct JSONPATH query. - Test the setup: After making the changes, monitor the logs to ensure the battery level is being correctly received and displayed.
This solution not only resolved my issue but also gave me a deeper understanding of how JSONPATH works within OpenHAB. It’s a great feeling to finally see that battery level update in real-time!
I hope this helps anyone else struggling with similar MQTT transformations. Happy automating! 