Detector Building C

[gz839918]

Is this even on the rules? I know this was a thing for the trial event but I don't see anything on the official rules about having to withstand a water test.

I mean if the probe is measuring the temperature of water I'd assume it would have to be waterproof to put it in safely...

Dxu is right that there’s no boiling water test or durability test anymore, but it still has to be waterproof...

The end of your detector "must be immersible up to 15.0 cm of water" by rule 3.b. I'm sorry if I confused anybody for saying durability would be "tested," because durability is no longer its own component, as dxu correctly pointed out. I guess the implication is that if your device melts or breaks due to water during the event, your device would be flagged with a construction violation.

[TheMysteriousMapMan]

I know it's all just nomenclature, but is Detector Building a Lab or a Build event? Are all events with both a hands-on and a theory portion a lab, or does it have to do whether it is a prebuild?

[Unome]

I know it's all just nomenclature, but is Detector Building a Lab or a Build event? Are all events with both a hands-on and a theory portion a lab, or does it have to do whether it is a prebuild?

I am not sure why it's classified under builds. Probably because under trial rules it was mostly pure build. It's under Tech rather than Physics, although I wouldn't be surprised if it got traded into Physics eventually (if/when Tech finds another event to fill the Robot Arm hole). As the rules are now, I would classify it as a lab event.

[jinhusong]

This list is so quiet, so I am just going to post something.

This year, I will coach 3 C teams (same school) for building events.

Here are some my thoughts, any feedback are welcome.

1. Calibration Curve fit: thermistor with full Steinhart–Hart equation, 4 points. TMP36/M35: also 4 points to the 3rd degree of polynomial.

2. ADC: Arduino built-in ADC only 10 bits, too tight for 0.1 degree C, so plan to use 16 Bit ADC (ADS1115).

3. ~1000 readings to average.

4. Advanced circuit for probe electronics.

5. Arduino will be used. Just because more kids are familiar with Arduino and cheaper to buy. External ADC will be used, so Raspberry Pi is also possible.

Will ask kids to study how thermistor and TMP36 work, how ADC works, how LED works. They already know Arduino.

Tiger (Jinhu)

[jinhusong]

FAQ:

(Section: 3 / Paragraph: b / Line: 1)
10/09/2019
ARE WE ALLOWED TO USE MORE THAN ONE TEMPERATURE SENSOR AND USE AN AVERAGE READING OF THEM, OR IS THERE A LIMIT OF ONLY ONE INPUT DEVICE?
No, only one sensor per device is allowed.

==============
I was thinking use different thermistors for reading temperature close to 0 degree C and 75 degree C. Well, just have to pick one, maybe 10kohm or 20kohm.

Tiger

[pepperonipi]

FAQ:

(Section: 3 / Paragraph: b / Line: 1)
10/09/2019
ARE WE ALLOWED TO USE MORE THAN ONE TEMPERATURE SENSOR AND USE AN AVERAGE READING OF THEM, OR IS THERE A LIMIT OF ONLY ONE INPUT DEVICE?
No, only one sensor per device is allowed.

==============
I was thinking use different thermistors for reading temperature close to 0 degree C and 75 degree C. Well, just have to pick one, maybe 10kohm or 20kohm.

Tiger

Yeah, I feel that using multiple thermistors would defeat the purpose of the event. At that point, I feel some teams may attempt to just very finely tune lots of individual thermistors, which takes away a lot of the challenge...

[lindsmaurer]

FAQ:

(Section: 3 / Paragraph: b / Line: 1)
10/09/2019
ARE WE ALLOWED TO USE MORE THAN ONE TEMPERATURE SENSOR AND USE AN AVERAGE READING OF THEM, OR IS THERE A LIMIT OF ONLY ONE INPUT DEVICE?
No, only one sensor per device is allowed.

==============
I was thinking use different thermistors for reading temperature close to 0 degree C and 75 degree C. Well, just have to pick one, maybe 10kohm or 20kohm.

Tiger

Yeah, I feel that using multiple thermistors would defeat the purpose of the event. At that point, I feel some teams may attempt to just very finely tune lots of individual thermistors, which takes away a lot of the challenge...

Yeah but it’s also kind of disappointing... I was also going to use one NTC and one PTC thermistor for different ranges

[kendreaditya]

1. Calibration Curve fit: thermistor with full Steinhart–Hart equation, 4 points. TMP36/M35: also 4 points to the 3rd degree of polynomial.

So in #1, you said "full Steinhart–Hart equation, 4 points", does the 4 points mean, input 4 points instead of 3? Because in my findings, I have discovered that it decreases accuracy.

Edit: It sounds like it shouldn't, but it does, I have no idea why

[pepperonipi]

2. ADC: Arduino built-in ADC only 10 bits, too tight for 0.1 degree C, so plan to use 16 Bit ADC (ADS1115).

Isn't this not allowed, according to the FAQ?

(Section: 3 / Paragraph: a / Line: 1)
10/13/2019
MAY STUDENTS ADD A MODULAR ANALOG-TO-DIGITAL CONVERTOR (ADC) TO THEIRMICROCONTROLLER?

No. External signal conditioning boards are not allowed.

[kendreaditya]

2. ADC: Arduino built-in ADC only 10 bits, too tight for 0.1 degree C, so plan to use 16 Bit ADC (ADS1115).

Isn't this not allowed, according to the FAQ?

(Section: 3 / Paragraph: a / Line: 1)
10/13/2019
MAY STUDENTS ADD A MODULAR ANALOG-TO-DIGITAL CONVERTOR (ADC) TO THEIRMICROCONTROLLER?

No. External signal conditioning boards are not allowed.

That's kinda weird cause it does not say anywhere in the rules that you can't. Plus, Raspberry Pi's don't have a built-in ADC, so you are forced to only use a digital sensor if you go that route.