RPM and Temperature Sensor

[wadiprawita]

Dear All,

I want to make engine RPM and temperature sensor that will be integrated to my autopilot (paparazzi-like autopilot).

Any suggestion ?

Thank's

-doni-

[zik]

I'm using a DS18S20 for ambient temperature measurement. It's cheap and easy. You'll need something which can handle higher temperatures if you want to measure the body of a gas engine, probably a thermocouple.

[Dan_Jones]

I prefer the MAX6674 or MAX6675 chips from Maxim to read K thermocouples. You can get the thermocouples from Omega and I suggest connecting them to the circuit board with screw terminals since standard solder will not stick to the thermocouple wire. There is a possibility of a cold junction compensation error with the screw terminal, but it is typically less than a few degrees. Hopefully that is accurate enough for you.

[zik]

Another possibility for sensors is to use these ready-made ones from Eagle Tree Systems. I don't know what the protocol is but I'm guessing it might be just I2C.

http://www.eagletreesystems.com/MicroPower/micro.htm

[wadiprawita]

Dear All,

Thank you for the reply, how about the RPM sensor ? Any suggestion ?

Thank's

-doni-

[vector_vortex]

I think a Hall Effect sensor with magnet on the shaft or Optical would be the way to go,
Also those eagle tree temp sensors only have two pins by the look of it so it's probably just at thermocouple with no calibration/conversion hardware, you would need a 6675 or similar as well.

Joel

[wadiprawita]

Any suggestion where can I get this hall effect and magnet component and what type (online shop such as www.digikey.com or www.newark.com will be nice).


for Joel,

for the temperature sensor, do you mean MAX6675 ?

Thank's

-doni-

[vector_vortex]

eagle tree systems have hall effect sensors plus magnets for US $10 otherwise digikey has many just look it up in their search utility, you still might need some buffering circuitry to make the output compatible with the rest of your system.

I found these parts on digikey:
AH180-PL-ADICT-ND

620-1043-ND

when I mentioned the 6675 I meant the MAX6675 but it needs to be used in conjunction with a k type thermocouple to measure temperature,
Have fun
Joel