Has anyone out there used a Bluetooth monitor to monitor a 12V DC battery? I have an existing hardware product that’s already in the field and a new feature I’d love to add is monitoring of a 12V DC battery.
The obvious way to do this would likely be a voltage divider and use some GPIO pins and read the voltage that way. This would be doable but I’d prefer to offer an “upgrade” to existing people who already have our product without having to swap out hardware.
The nice approach would be to do it over Bluetooth. I was thinking something like this:
So… has one one used one of these with a Boron or Bsom? Is there a certain aspect or way to search for these where I’d know it would interface/communicate properly?
Any guidance or examples would be greatly appreciated!
The biggest question in my mind is if you'll be able to figure out how to get the data out of it. If it uses standard BLE battery profiles it will be easy. You might be able to scan the characteristics and guess. However, if they've implemented a custom protocol or have authentication it will be a lot more complicated.
Thanks Rick. Yeah, that’s kind of what I figured… it’s all about the protocol and decoding the measured voltage. I’m hoping someone else out there already accomplished this or know of a hardware that the BLE transmission is well defined and open.
Suppose I could make my own and define the BLE transmission myself but that sounds like a lot of effort. I’d rather just buy someone else’s hardware and get it to communicate.
I figured I’d ask here to see if anyone else has got something like this working.
@gusgonnet, it's the mobile app. There are many insights into the way the BLE works and how the application is spying and connecting to its backend to "verify" the BLE device.
Hi. Well, I got "nuthin"! But, I wanted to thank you for your post about the battery monitor. While researching your link, I found something similar from Victron Energy. I knew about most of their equipment but did not know about this:
https://www.victronenergy.com/meters-and-sensors/smart-battery-sense
I ordered one today. I am planning on using the app to access voltage and tempF from a 12V battery. From what @peekay123 posted I am hoping Victron would not go that route but who knows? So, I looked further on in the support section at Victron and found the following post in victron_community. Maybe it could help you out from a Boron/Bsom development perspective:
that's a nice find.
The ble data may be made hard to decode from a Particle device since it appears to be encrypted, with a key per device:
Encryption Key
The device status messages published by the Victron device are encrypted. In order to decrypt them the device encyption key is needed. This can be found for a given device using the Victron Connect app on iOS or Android.
Using the app, connect to the device, then go to Settings -> Product Info -> Encryption data.
Wow.. love the ideas and conversations here for everyone. That Victron Energy smart battery sense is exactly what I need. It’s a bummer it’s encrypted like that. Keep the ideas and product references coming… I hope to eventually find something.
Just a little more context… many maple syrup producers (especially small ones) run a 12V RV style diaphragm pump. They are completely off grid so just use a 12V battery to run the pump. They normally get 1-2 days of constant running. Some guys then rig up solar panels, others will swap out batteries to charge. Having the ability to monitor this voltage would make their lives easier to know when to swap out the battery. Thought I’d share the background for the fun of it…
Yeah, if it was for my own hardware setup this is certainly an option. I’d like to add it as an option to the fleet of devices already out in the field without having to retrofit hardware.
I’d prefer to just allow them to add it via Bluetooth. That way it’s just send them the Bluetooth voltage monitor, do an OTA update to the device and it can start listening for the additional BLE sensor. This is the approach I’m taking for adding additional temperature sensors. I’d love to take that same approach for voltage monitoring without having to spin up my own BLE hardware.