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Hi,
last year I bought the Cerbo S GX with the idea I didn't need the analog inputs. Things changed now I would like to connect a temperature sensor to my (electric) motor.
So the question is, is there a way I can connect a temperature sensor to the Cerbo S GX? Wired and able to handle heath above 100 degrees (hopefully not).
I have the same issue. Very interested in the responses.
Apparently, literally the first result when searching, Victron use a an LM335Z temperature sensor...
So... The Cerbo is almost certainly driving its temperature inputs with constant current and looking for a voltage between the + and - which is interpreted as a temperature based on the LM335Z speck. I do know that the Smart shunt temperature and Cerbo differ, so the calibration of at lest those two examples of a temperature input are different.LM335Z
To be clear here I do not know this to be the case but it seems reasonable. whatever the case LM335Z, NTC, PTC, whatever, there will be a drive voltage, or current, and either current or voltage will be being sensed, voltage being far easier, so way more likely. in terms of linearity, anything could work, but from a design point of view a device that approximates linear temp/volt drop in the desired sensing range makes sense.
Virtually all analogue inputs, on any device, are looking at voltage, a dedicated current input will likely be looking at voltage a across a calibrated burden resistor but still voltage under the hood.
Temperature is a bit of a wrinkle because most temperature sensors are not entirely linear and passing current through them actually creates heat, which influences the measurement.
We are talking about calibration and drive... A temperature input is looking for a voltage on its drive output, which will be current limited in some way. The interpreted temp is then calibrated based on the sensor that is expected to be attached. A general analogue input will not have a current source and will likely report a linear relationship between the voltage it sees and the raw value it reports.
Hope that helps.
Alistair, this is of no use, the issue is the Cerbo GX-S does not have analogue inputs so you can not connect temperature sensors or tanks to it so info on wired temperature sensors is of little use.
BTW did you write all that yourself or harvest it from AI.
The only way is to use Bluetooth Ruuvi sensors but they have a max ange of 70degC so will not cover your higher end.
Sorry about that, I should have checked the input capability before waxing lyrical about something that cant happen, I just assumed hardware inputs were available... Silly. I wonder if AI would have been so silly?
Anyhoooo...
The Cerbo S GX can run Large OS, which means you can do loads, almost anything, with it.
In your case probably the simplest way to get temperature is to use a Modbus IO module with PT100 RTD inputs, up to 127 of them on a single bus, and collect that data over Ethernet using an a Modbus TCT / RTU gateway
What you do with the temperature info when you have it will depend on what you want and if the Victron system is capable of using it.
I do not know if you can write to any if the Victron systems that can measure temperature, but I suspect not. You can however control charge current, for example, so if you wanted to temperature compensate charging you could set you system to the most aggressive charge you need and then throttle it externally in response to temperature changes.
Again, sorry I didn't fact check my original answer, lesson learned.
