analog input 0 to +5v what is with -5V?

Hello i have a sensor which could send up to -5v normally 0 to +5v,
this is an strain gaughe, if the weigt is under 0 kg it sends although negative voltagesup to -1 V maximum -5V.

do i destroy the arduino with -1 up to -5v?

Whar can i do that only 0 to +5v comes into the arduino if needet.

Thanks

do i destroy the arduino with -1 up to -5v?

Yes.

Whar can i do that only 0 to +5v comes into the arduino if needet.

You can protect against the negative input with clamping diodes, or you can divide the input by two and apply a shift of 2.5V.

Thnks a ot.
Which diode can i use.
i have one ZP IN 4007 9649.

Thanks

Any diode will do but a schlocky diode is best because it starts to conduct with less voltage across it.

Hello thanks, i have one shotkeydiode, so i will use this one.

I have tested this and is running.

do i need a resistor beetween the + and GND, the sampled data is not 0 and runs up to 100 by 0v.

is there any wiring picture for arduino wich uses not the own +5v pin (works with extrnal voltage)

Thanks

do i need a resistor beetween the + and GND, the sampled data is not 0 and runs up to 100 by 0v.

Sorry I don't understand that. Can you post a diagram of what you have. Just photpgraph a pencil drawing.

You will need to somehow read the small signal from the strain gauge.

I would suggest using an opamp to strengthen the signal and then use an external analog to digital converter
chip which can read both +ve and -ve values and then report the value to the arduino using I2c or SPI.

Does your sensor have it's own power source? If it is just a passive strain gauge then it can not generate -5V. Please provide a link to the sensor you are using.

Sorry for my bad english.

here is the picture.
R must be high but what is recomendet?

Thanks

Grafik.jpg

i have a straingaughe with a Load cell amplifier from SMOWO ST01

The user manual says nothing about a negative output voltage? So do you need this protection?

here is the picture.

No the diode must be where the resistor is and the resistor must be between the diode and the output of your sensor. The cathode of the diode must be on the ground.

Hi Mike,

can you send aPicture?
which resistor mut it be?

Thanks

http://www.thebox.myzen.co.uk/Tutorial/Protection.html

But as I said you don't get neg voltages from that sensor.