In the course of migrating an oil meter into my Victron environment (and maybe VRM as well), I did connect its reed contact to a digital input of my Cerbo GX. I did not find any settings in the Cerbo to de-bounce the reed contact; I had to use an additional device in between to get this done. It’s a counter with the option to set up de-bouncing on its inputs and also provides configurable (open collector) outputs to properly drive Cerbo’s digital input.
Now I noticed that over time Cerbo seems to miss pulses. From 430,793 pulses, Cerbo only shows 430,627. This doesn’t seem to be that much, but my plan is to calculate my oil consumption from it.
To validate that Cerbo’s input is the problem, I verified the following:
a) I checked that input signal/voltage is in range using oscilloscope/multimeter.
b) I connected an additional counter in parallel to Cerbo’s input. That counter is showing the correct number of pulses.
c) the blue input LED always shows the correct input status.
d) I checked CPU load and response time of Cerbo GX via VRM. “D-bus round trip time” is usually below 7 milliseconds with 10 short peaks up to 20 ms during the past 6 months. CPU load is usually below 50%, load average below 5.
Cerbo is running the large firmware image as I’m using Node-RED to display some data in a dashboard as well as sending HTTP requests to a statistics tool. No additional software/tools are installed.
The frequency of the pulse is between 0.5 and 1 Hertz which shouldn’t be that big challenge for the Cerbo GX.
As I’m running out of ideas about what the problem might be, I’m hoping for some helpful suggestions from the community.
My wild guess: if the heater stops, the reed contact may be either in open or closed state. Cerbo may drop/time-out a closed status without counting, although the blue input LED always shows the correct status.
Cheers
-Andreas