LPC55s69 ADC and internal temperature sensor do not work together

rkulkarni — Fri, 21 Jul 2023 05:33:13 GMT

I am trying to run the internal ADC and the internal temperature sensor together in LPC55s69-EVK board. I am able to run both separately but when tried together, the temperature sensor gives very high values. I suspect there is some problem with ADC configuration when running both together. I am attaching the ADC initializations for both below. I am initializing the ADC then taking channel 0 value, then again initializing ADC for temperature sensor and then taking temperature values. Thank you for your help in advance.

For ADC:

LPADC_DoResetConfig(ADC_LPADC_BASE);

CLOCK_SetClkDiv(kCLOCK_DivAdcAsyncClk, 8U, true);

CLOCK_AttachClk(kMAIN_CLK_to_ADC_CLK);

/* Disable LDOGPADC power down */

POWER_DisablePD(kPDRUNCFG_PD_LDOGPADC);

ANACTRL_Init(ANACTRL);

ANACTRL_EnableVref1V(ANACTRL, true);

LPADC_GetDefaultConfig(&mLpadcConfigStruct);

mLpadcConfigStruct.enableAnalogPreliminary = true;

mLpadcConfigStruct.referenceVoltageSource = ADC_LPADC_VREF_SOURCE;

mLpadcConfigStruct.conversionAverageMode = kLPADC_ConversionAverage128;

LPADC_Init(ADC_LPADC_BASE, &mLpadcConfigStruct);

LPADC_SetOffsetValue(ADC_LPADC_BASE, ADC_LPADC_OFFSET_VALUE_A,

ADC_LPADC_OFFSET_VALUE_B);

LPADC_DoAutoCalibration(ADC_LPADC_BASE);

LPADC_GetDefaultConvCommandConfig(&mLpadcCommandConfigStruct);

mLpadcCommandConfigStruct.channelNumber = ADC_LPADC_USER_CHANNEL;

LPADC_SetConvCommandConfig(ADC_LPADC_BASE, ADC_LPADC_USER_CMDID,

&mLpadcCommandConfigStruct);

/* Set trigger configuration. */

LPADC_GetDefaultConvTriggerConfig(&mLpadcTriggerConfigStruct);

mLpadcTriggerConfigStruct.targetCommandId = ADC_LPADC_USER_CMDID;

mLpadcTriggerConfigStruct.enableHardwareTrigger = false;

LPADC_SetConvTriggerConfig(

ADC_LPADC_BASE, 0U,

&mLpadcTriggerConfigStruct); /* Configurate the trigger0.*/

For temperature sensor:

LPADC_DoResetConfig(DEMO_LPADC_BASE);

BOARD_BootClockPLL1_150M();

CLOCK_AttachClk(kEXT_CLK_to_PLL0); /*!< Switch PLL0CLKSEL to EXT_CLK */

POWER_DisablePD(kPDRUNCFG_PD_PLL0); /* Ensure PLL is on */

POWER_DisablePD(kPDRUNCFG_PD_PLL0_SSCG);

const pll_setup_t pll0Setup = {

.pllctrl = SYSCON_PLL0CTRL_CLKEN_MASK | SYSCON_PLL0CTRL_SELI(19U) | SYSCON_PLL0CTRL_SELP(9U),

.pllndec = SYSCON_PLL0NDEC_NDIV(1U),

.pllpdec = SYSCON_PLL0PDEC_PDIV(16U),

.pllsscg = {0x0U, (SYSCON_PLL0SSCG1_MDIV_EXT(32U) | SYSCON_PLL0SSCG1_SEL_EXT_MASK)},

.pllRate = 16000000U,

.flags = PLL_SETUPFLAG_WAITLOCK};

CLOCK_SetPLL0Freq(&pll0Setup);

CLOCK_SetClkDiv(kCLOCK_DivAdcAsyncClk, 0U, true); /*!< Reset ADCCLKDIV divider counter and halt it */

CLOCK_SetClkDiv(kCLOCK_DivAdcAsyncClk, 4U, false); /*!< Set ADCCLKDIV divider to value 4 */

CLOCK_AttachClk(kPLL0_to_ADC_CLK); /*!< Switch ADC_CLK to PLL0 */

/* Disable LDOGPADC power down */

POWER_DisablePD(kPDRUNCFG_PD_LDOGPADC);

/* Disable Temperature sensor power down. */

POWER_DisablePD(kPDRUNCFG_PD_TEMPSENS);

ANACTRL_Init(ANACTRL);

ANACTRL_EnableVref1V(ANACTRL, true);

LPADC_GetDefaultConfig(&lpadcConfigStruct);

lpadcConfigStruct.enableAnalogPreliminary = true;

lpadcConfigStruct.powerLevelMode = kLPADC_PowerLevelAlt4;

lpadcConfigStruct.referenceVoltageSource = DEMO_LPADC_VREF_SOURCE;

lpadcConfigStruct.conversionAverageMode = kLPADC_ConversionAverage128;

lpadcConfigStruct.FIFO0Watermark = FSL_FEATURE_LPADC_TEMP_SENS_BUFFER_SIZE - 1U;

LPADC_Init(DEMO_LPADC_BASE, &lpadcConfigStruct);

LPADC_DoResetFIFO0(DEMO_LPADC_BASE);

LPADC_SetOffsetValue(DEMO_LPADC_BASE, DEMO_LPADC_OFFSET_VALUE_A, DEMO_LPADC_OFFSET_VALUE_B);

LPADC_DoAutoCalibration(DEMO_LPADC_BASE);

LPADC_GetDefaultConvCommandConfig(&g_LpadcCommandConfigStruct);

g_LpadcCommandConfigStruct.channelNumber = DEMO_LPADC_TEMP_SENS_CHANNEL;

g_LpadcCommandConfigStruct.sampleChannelMode = DEMO_LPADC_SAMPLE_CHANNEL_MODE;

g_LpadcCommandConfigStruct.sampleTimeMode = kLPADC_SampleTimeADCK131;

g_LpadcCommandConfigStruct.hardwareAverageMode = kLPADC_HardwareAverageCount128;

g_LpadcCommandConfigStruct.loopCount = FSL_FEATURE_LPADC_TEMP_SENS_BUFFER_SIZE - 1U;

g_LpadcCommandConfigStruct.conversionResolutionMode = kLPADC_ConversionResolutionHigh;

LPADC_SetConvCommandConfig(DEMO_LPADC_BASE, DEMO_LPADC_USER_CMDID, &g_LpadcCommandConfigStruct);

/* Set trigger configuration. */

LPADC_GetDefaultConvTriggerConfig(&lpadcTriggerConfigStruct);

lpadcTriggerConfigStruct.targetCommandId = DEMO_LPADC_USER_CMDID;

LPADC_SetConvTriggerConfig(DEMO_LPADC_BASE, 0U, &lpadcTriggerConfigStruct); /* Configurate the trigger0. */

Re: LPC55s69 ADC and internal temperature sensor do not work together

xiangjun_rong — Fri, 21 Jul 2023 08:15:35 GMT

Hi,

I see that you want to sample both ADC channel 0 and internal temperature sensor, for the case, I suggest you use one command ID and use analog channel chain to chain the ADC channel0 and temperature sensor.

I suggest you refer to the community:

https://community.nxp.com/t5/LPC-Microcontrollers-Knowledge/Multiple-ADC-channels-conversion-with-CTimer-triggering-once-for/ta-p/1666831

Hope it is helpful

XiangJun Rong

Re: LPC55s69 ADC and internal temperature sensor do not work together

rkulkarni — Mon, 24 Jul 2023 11:24:26 GMT

Okay will try this once, Thanks!

LPC MicrocontrollersのトピックLPC55s69 ADC and internal temperature sensor do not work together

LPC55s69 ADC and internal temperature sensor do not work together

Re: LPC55s69 ADC and internal temperature sensor do not work together

Re: LPC55s69 ADC and internal temperature sensor do not work together