looking for a simple sensor to play with

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yefj

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Hello,I am looking for a sensor without the ADC part in it.only the sensor which will output analog signal .no matter what sensor just something i could start play with.
Thanks.
 

The simplest is a pot ...
or a resistor divider. So you can use it as DVM for DC voltages.
Or a LM35 temperature sensor.

A BJT can be used as a temperature sensor, too. Since it's V_be will drift by about -2mV/°C.

Klaus
 
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You can also use a thermistor.
 

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Yes i will order it then.
another question I know we have ADC periphery i can use,is there someexternal ADC component i could use for this device?
Thanks
 

Hi,

of course there are many external ADCs available. But the question is

- Which resolution do you want/need?
- Which update rate?
- Which communication interface (I²C, SPI, parallel)?

A good solution might be the MCP3424 [1] or the MCP3561 [2]. Both have an internal PGA with might be usefull when dealing with small voltages/temperature changes. But have in mind the LM35 accuracy is around \[\pm\]0.5 °C.

[1] https://www.microchip.com/wwwproducts/en/MCP3421
[2] https://www.microchip.com/wwwproducts/en/MCP3561

BR
 

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Hi,

yes those two ICs can be used together. The absolut maximum junction temperature for the LM35 is 150 °C. Thus the maximum output voltage is 1.5 V. The ADC's maximum input voltage in single mode is 2.048 V.

The ADC supports a resolution from 12 bit up to 18 bit, depending on the used data rate. The resolution ranges from 1 mV up to 15.625 uV.

So for an accuracy of +-2 °C @ Ta = 25 °C (+-2 mV) the 12 bit mode alreday provides a higher resolution than the accuracy of the LM35.

BR
 
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