https://community.nxp.com/t5/LPC-Microcontrollers/LPCXpresso845MAX-use-ADC-Seqa-Seqb-example-code-have-pulse-on/m-p/1165742#M42529 <P>Why LPCXpresso845MAX use ADC_Seqa_Seqb example code have pulse on ADC2(PIO14) pin when get ADC value?<span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="Inkedadc_LI.jpg" style="width: 999px;"><img src="https://community.nxp.com/t5/image/serverpage/image-id/127179i49A31A19B54BBC3C/image-size/large?v=v2&amp;px=999" role="button" title="Inkedadc_LI.jpg" alt="Inkedadc_LI.jpg" /></span><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="Tera_ADC.jpg" style="width: 627px;"><img src="https://community.nxp.com/t5/image/serverpage/image-id/127181iFEB60E4BACA5C343/image-size/large?v=v2&amp;px=999" role="button" title="Tera_ADC.jpg" alt="Tera_ADC.jpg" /></span></P> Mon, 12 Oct 2020 02:58:05 GMT ristchen 2020-10-12T02:58:05Z https://community.nxp.com/t5/LPC-Microcontrollers/LPCXpresso845MAX-use-ADC-Seqa-Seqb-example-code-have-pulse-on/m-p/1165742#M42529 <P>Why LPCXpresso845MAX use ADC_Seqa_Seqb example code have pulse on ADC2(PIO14) pin when get ADC value?<span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="Inkedadc_LI.jpg" style="width: 999px;"><img src="https://community.nxp.com/t5/image/serverpage/image-id/127179i49A31A19B54BBC3C/image-size/large?v=v2&amp;px=999" role="button" title="Inkedadc_LI.jpg" alt="Inkedadc_LI.jpg" /></span><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="Tera_ADC.jpg" style="width: 627px;"><img src="https://community.nxp.com/t5/image/serverpage/image-id/127181iFEB60E4BACA5C343/image-size/large?v=v2&amp;px=999" role="button" title="Tera_ADC.jpg" alt="Tera_ADC.jpg" /></span></P> Mon, 12 Oct 2020 02:58:05 GMT https://community.nxp.com/t5/LPC-Microcontrollers/LPCXpresso845MAX-use-ADC-Seqa-Seqb-example-code-have-pulse-on/m-p/1165742#M42529 ristchen 2020-10-12T02:58:05Z https://community.nxp.com/t5/LPC-Microcontrollers/LPCXpresso845MAX-use-ADC-Seqa-Seqb-example-code-have-pulse-on/m-p/1166482#M42538 <P>Hi, Chen,</P> <P>I have checked the voltage spike on the PIO14/ADC2, I suppose this is a noise, the noise generally happens for the float input pins or high impedance input pin.</P> <P>I suggest that you can connect a RC circuit for the ADC analog input channel. for example, this is a RC circuit, using 100 ohm and 2.2nF capacitor.</P> <P>&nbsp;</P> <P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="xiangjun_rong_0-1602566803097.png" style="width: 400px;"><img src="https://community.nxp.com/t5/image/serverpage/image-id/127312iB3495DFAB42717BE/image-size/medium?v=v2&amp;px=400" role="button" title="xiangjun_rong_0-1602566803097.png" alt="xiangjun_rong_0-1602566803097.png" /></span></P> <P>Does the noise take effect on the ADC sample?</P> <P>BR</P> <P>XiangJun Rong</P> Tue, 13 Oct 2020 05:28:26 GMT https://community.nxp.com/t5/LPC-Microcontrollers/LPCXpresso845MAX-use-ADC-Seqa-Seqb-example-code-have-pulse-on/m-p/1166482#M42538 xiangjun_rong 2020-10-13T05:28:26Z