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Re: Detector Building C

Posted: February 24th, 2020, 2:29 pm
by rabbitman
Umaroth wrote:
February 23rd, 2020, 4:25 pm
smallboar wrote:
February 23rd, 2020, 3:26 pm
I'm new to this event, what microprocessor is easier to learn/use, Ti or arduino?
Do yourself a favor and use arduino, it's more practical and useful for the future. The only reason TI is suggested is because they're the sponsors.
only the absolute best are capable of wielding the legendary power of the TI Innovator

Re: Detector Building C

Posted: February 24th, 2020, 5:07 pm
by MoMoney$$$;)0)
I have found that extremely FALSE.

JKJK

You can do perfectly fine with it, it's just the fact that you're going to have to fine tune it like any other detector.

Re: Detector Building C

Posted: February 24th, 2020, 5:25 pm
by pepperonipi
rabbitman wrote:
February 24th, 2020, 2:29 pm
Umaroth wrote:
February 23rd, 2020, 4:25 pm
smallboar wrote:
February 23rd, 2020, 3:26 pm
I'm new to this event, what microprocessor is easier to learn/use, Ti or arduino?
Do yourself a favor and use arduino, it's more practical and useful for the future. The only reason TI is suggested is because they're the sponsors.
only the absolute best are capable of wielding the legendary power of the TI Innovator
We tried it and I did not like the fact that the TI Innovator basically has little to no community behind it, which can certainly make it a little hard to get answers to coding questions or overall use questions. It was certainly usable, but I do not regret switching back to Arduino.

Re: Detector Building C

Posted: February 25th, 2020, 4:51 am
by lindsmaurer
I've always used arduino because that's the same design that I used back when this was a trial, and it's accurate while being fairly simple to make.

Re: Detector Building C

Posted: March 2nd, 2020, 7:58 pm
by MTV<=>Operator
Is there any reason why a thermistor would display a different voltage for the same temperature than it did two weeks ago? This seems to have happened with my device and now I'm not sure I can trust it to not change before the competition

Re: Detector Building C

Posted: March 2nd, 2020, 8:30 pm
by jinhusong
Did you measure or calculate the resistance? Maybe your battery is low?

Re: Detector Building C

Posted: March 3rd, 2020, 3:04 pm
by MTV<=>Operator
I thought low battery would only impact a linear analog to digital sensor, not a thermistor? I tried switching batteries and the readings all remained the same. For reference, two weeks ago the device would read a voltage of 395 for 15 degrees, but now it reads a voltage of 380 for 15 degrees. Nothing was changed. I didn't measure the resistance to begin with, I just related voltage directly to temperature with a 5 part piecewise function.

Re: Detector Building C

Posted: March 4th, 2020, 8:00 am
by Jashan12
What is a solid score on the reading temperature section (out of 60)?

Re: Detector Building C

Posted: March 4th, 2020, 9:20 am
by jinhusong
MTV<=>Operator wrote:
March 3rd, 2020, 3:04 pm
I thought low battery would only impact a linear analog to digital sensor, not a thermistor? I tried switching batteries and the readings all remained the same. For reference, two weeks ago the device would read a voltage of 395 for 15 degrees, but now it reads a voltage of 380 for 15 degrees. Nothing was changed. I didn't measure the resistance to begin with, I just related voltage directly to temperature with a 5 part piecewise function.
You can try with another thermistor to see if any change. Normally, change thermistor will not change the voltage that much.

Better do debug, assuming you are using the standard voltage-divide circuit, like a 10k ohm reference resistor serial with a 10k thermistor.
Use multimeter to check voltage at each points on the circuit of the thermistor and compare with the value from calculation (you can calculate the supposed voltage from the temperature and the reference resistor).

BTW, voltage "395", raw ADC integer?
What voltage you power the thermistor circuit? What is the range and bits of your ADC (Arduino UNO is 10bits, range is 5.0V, 1.1V, or user input) ? Any change of these will affect the voltage reading.

Re: Detector Building C

Posted: March 4th, 2020, 8:40 pm
by nisha01
Hello, I am currently working with the TI LM 19 as my sensor. I waterproofed it with a hard plastic straw, saran wrap, and tape. However, when I did my voltage versus temperature graph, the reading was not close to being linear, and the best line of fit did not seem like a good option to get the right temperature since it was very broad. Also, when I calculated my temperature with my negative slope and a y-intercept in the 200s, I noticed the temperature is extremely off.

Would you recommend switching thermistors, or what are the other errors that could be made? Please let me know, my competition is in very few days.