LM71-Q1: How to simulate LM71-Q1 with C code?

Mangesh Dhakane

Part Number: LM71-Q1
Other Parts Discussed in Thread: LM71

I need formula to convert temperature value especially negative temperature to convert into Hex format as per LM71.

example - how to convert -40degC to Hex value 0xEC03. I have referred the Datasheet - https://www.ti.com/lit/ds/symlink/lm71.pdf?ts=1652094526792&ref_url=https%253A%252F%252Fwww.google.com%252F

but it's clear to me.

over 2 years ago

0 Jalen Tate89 over 2 years ago

TI__Genius 9675 points

Hi Mangesh,

I will work to provide this to you shortly.

Jalen

0 Jalen Tate89 over 2 years ago

TI__Genius 9675 points

Mahesh,

As mentioned in the datasheet "Temperature data is represented by a 14-bit, two's complement word with an LSB (Least Significant Bit) equal to 0.03125°C".

Below is the c code to convert the digital format into a temperature reading, assuming you have 2 bytes to begin with and not a 16 bit.

float temp = ((int16_t) ((uint8_t) byte1) << 8 | ((uint8_t) byte2)) >> 2 * 0.03125;

Jalen

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LM71-Q1: How to simulate LM71-Q1 with C code?