Temp readings and voltage input

[ruijc]

It's for the engine temp.

The max 120ºC of the DS18B20 is not enough.

I need to be able to read safely up to 140ºC.

I know you will say that the engine cannot reach that temperature unless it's toast, but the real thing is that with 30% nitro they can have peeks of 130ºC/135ºC. Not too good for the engine, it's true, but i need to measure it's peeks to know how the engine is running in mid air

.

[Acetronics2]

...

Do not tell me you didn't know that :

http://www.venom-group.com/print_mot...structions.pdf

...

Alain

[ruijc]

Now i see what you mean.

I did not knew this.
Sensor reaches 200ºC ??? wow...and now i undestand why you recomended NTCs.
But this is a failsafe unit.

I know this one instead:
http://www.rcmodels.org/csm/carbsmart.pdf
I believe it's by far the best idea.

Apart from these 2...
My circuit is not like any of these.
It just stores the values, nothing else.

.

[Acetronics2]

Ahhhhh,

CSM !!! I bought one gyro from them ( ICG360 ) Heading "lock" was gently unsteady ( ! )... carefully trimmed parameters for a plane.

and then ... servo got dead-locked to neutral - and no way to reset the gyro parameters !!!

No help from CSG nor ( except buy the new 540 model at a fair price ...)

The sensor ( and its NTC ) is now in my Sensors box !!!

Alain

[ruijc]

Yeah...gyros i only like futaba's my self

And i have to change the code to:

temp= (in */2500)>>2

Is this right ?

how about the code...will this work ok for 2,5V ref?

.

[Acetronics2]

for 10 bits ...

use V ref = 4.096v or 2.048 v ... but not 2.5 v

for 4.096 v you get 1 count for 1 mv
for 2.048 v you get 2 counts for 1 mv input ...

so, your formula ... is really awful !!!

100°C = 1 v ...

with a 2.5 v ref : 1v /2.5 *1024 counts ... 409.6 > 409

409*2500/256 / 4 = 998.5 ...

you will find the good numbers easily !

Alain

[Acetronics2]

Errata !!!

for 10 bits ...

use V ref = 4.096v or 2.048 v ... but not 2.5 v

for 4.096 v you get 1 count for 4 mv
for 2.048 v you get 1 count for 2 mv input ...


Alain