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When I power my esp32 with an USB cable and check the readings of JSN-SR04 it shows correct and consistent readings. But when I connect esp32 and jsn with 5v from LM2596 12V input errors are not correct and sometimes consistent. Can anyone help me with this?

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Either the voltage is not 5V, or it cannot supply the current or more likely there is an instability on the power rail. You need to check it with a scope. Also make sure you have all the recommended capacitors in place for smoothing the LM2596. My guess is residual spikes from the switching

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  • \$\begingroup\$ thanks for your reply. I dont have scope so I measured it with multimeter and the voltage is 5V. Esp is functioning normally, so I dont think there are any current issues. \$\endgroup\$ – user193395 Jul 10 at 9:04
  • \$\begingroup\$ @ACSreedharReddy It's like ly to be high frequency spikes on the line. Try adding a 100n ceramic capacitor to the PSU output, or maybe 1uF ceramic \$\endgroup\$ – Dirk Bruere Jul 10 at 10:22
  • \$\begingroup\$ Tried placing 100nF across lm2596 input. But could it did not help. \$\endgroup\$ – user193395 Jul 10 at 11:02
  • \$\begingroup\$ Another to thing to mention is even connecting esp32 with usb and common grounding jsn and esp with input 12v ground the issue exists. \$\endgroup\$ – user193395 Jul 10 at 11:16

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