Thermistor temperature reading issue after FlowCode component update

[OderlandoRSilva]

I've been using the thermistor component in my projects for a long time, and it's always worked well for me.
I recently noticed that new builds of old functional codes are showing errors in the thermistor readings, even if I haven't modified them.
I remember updating the FlowCode libraries. I don't know if that might have been the reason.
I'd like someone to test the thermistor component to see if the temperature readings work correctly. The readings I'm getting now are incorrect and out of line with the actual values.
I'm uploading some simple test code I created to test the readings.
The NTC is in pull-up mode, and the additional resistor is 7.5kΩ.
I'd appreciate it if anyone could help me with this verification.

[medelec35]

Hello.
Have you tried using a fixed resistor of the same value (10K) in place of the the thermistor, then getting the adc and temperature values?
If you can do that and let me know the results.
What is the value of VDD?

[OderlandoRSilva]

VDD is 3.3V.
I used a potentiometer to test: using approximately 9.2kΩ, the temperature is 25°C.
Reducing the resistance slightly (simulating a temperature increase on the NTC thermistor), the temperature reading immediately jumps to approximately 44°C. This is happening in several codes using the thermistor component.
It didn't happen before.
There is this discontinuity point at approximately 9.2kΩ.
I'm sending a GIF showing what I described.

[medelec35]

That possibly looks like a value rolling over.
There is a new thermistor component that I designed.
All that is required is for the beta from the datasheet to be entered.
It does not require calibrating at different temperatures.
Personally I and other people have found the temperature to be accurate.
There is even a temperature offset option.
The new thermistor component will work at any supply voltage without entering any voltages as the calculations cancel any voltage changes.

Tip use + supply rail for one end of the thermistor/fixed resistor potential divider, and use an IO pin for GND.
set the io pin to 0v wait 10ms then ReadTemperature, set IO pin back to +v.
In doing that there will be no thermistor self heating.


Browse to this location using file explorer , it's hidden by default so just paste the link into your address bar.

Code: Select all

%ProgramData%\MatrixTSL\FlowcodeV10\Components

Place the attached component.
If Flowcode is already open, then you will need to reload your project for the new component to work
If you run any component updates, then the component you added will be overwritten, so it will stop working again (unless the component update has been pushed).

I will look at the original thermistor component issue and see if I can sort it when back at work next week.

[OderlandoRSilva]

I had installed FlowCode a few months ago on another computer and hadn't updated the thermistor component. So, I decided to test it on that other computer:
I compiled my flowchart on the other computer. Temperature readings above 25°C worked fine.
After that, I updated the FlowCode components (including the thermistor). After that, I compiled the flowchart again and saw that the error reappeared.
I backed up this other computer before updating the components, so I can restore the original component that was on my computer. Therefore, I conclude that the problem lies with the thermistor component update.
I will still test the beta version.
I await news on a solution to this issue.

[OderlandoRSilva]

I remember seeing a post a while back where you explained the calculations for this beta version. Thank you for your great contribution, Martin.

[medelec35]

If you want to confirm if it was an update or not that caused the issue, take a look on how to rollback a component version

[OderlandoRSilva]

I followed these steps. I used the previous version of the thermistor. Now it's working again.
I didn't know about this tip. It really helped me a lot.
I'm very grateful for your help. I'm very satisfied. Thank you very much!

[OderlandoRSilva]

Hello. Has the problem with the thermistor component been verified?