Internal Temperature Sensor for LPC832

aaronm — Wed, 15 Feb 2023 07:13:42 GMT

In the example ADC code for the LPC824MAX evaluation board, the comments refer to an internal temperature sensor on ADC0, channel 1. I don't see anything specific about it in the documentation for the LPC824, and a google search doesn't really turn up any answers. Is there an official source for the internal temperature sensor? And does this same sensor exist on the LPC832 chip? I could use this to seed the random number generator, if I can confirm it exists and works as expected. My first pass with the ADC0 conversion on channel 1 on the LPC832 returns 0s, which doesn't seem correct.

Re: Internal Temperature Sensor for LPC832

xiangjun_rong — Wed, 15 Feb 2023 09:07:40 GMT

Hi,

I have checked all the UM of LPC8xx, none of them has on-chip temperature senor, so you can not use the on-chip ADC to measure the junction temperature for LPC8xx.

I have checked the ADC code in SDK package for LPC84x, but it is a bug, it should have been deleted.

#if !(defined(FSL_FEATURE_ADC_HAS_NO_INSEL) && FSL_FEATURE_ADC_HAS_NO_INSEL)
/* Use the temperature sensor input to channel 0. */
ADC_EnableTemperatureSensor(DEMO_ADC_BASE, true);
#endif /* FSL_FEATURE_ADC_HAS_NO_INSEL. */

For the LPC processor, if it has on-chip temperature senor, it should have the register.

The LPC8xx does not have the Input Select Register.

Hope it can help you

XiangJun Rong

topic Re: Internal Temperature Sensor for LPC832 in LPC Microcontrollers

Internal Temperature Sensor for LPC832

Re: Internal Temperature Sensor for LPC832