2 Replies Latest reply on Jun 6, 2017 2:25 PM by mario.pro2_1603066

    PSOC 4 with ESP8266 nad HC-SR501



      I have problem with mentioned devices. HC-SR501 motion sensor is always high when there is also a Wi-Fi module ESP8266 connected to my board. What could be the issue?

        • 1. Re: PSOC 4 with ESP8266 nad HC-SR501


          I have seen people sharing false triggering on  HC-SR501 when used with ESP8266. I will share the suggestions I have found.

          "I noticed 2 sources of evil of the false positives.
          1: Power supply interference, I tried 5 different usb adapters ranging from 500mA to 2A. I run now stable on a 500mA USB power from Ebay.
          2: Rf interference. Wifi is 2,4 Ghz ( in my case) RF. I tried two different HC-SR501 and both were triggerd bij RF.

          I tried also shielding. In my case it didn't help. My pir is only 5 cm away from the ESP.

          I solved this with the next solutions:
          A: Used a 47uF and 102pF power decompling consensator soldered over the pir power connections at the ESP8266 side.
          B: Put the ESP in 802.11G mode instead of 802.11N mode. I think the Rf spectrum will be less in G mode.
          C: Put the ESP in wifi STA mode only.
          D: Lower the ESP wifi output power to 10dBm."

          • 2. Re: PSOC 4 with ESP8266 nad HC-SR501

            Thank, actually I added 2 capacitors and now it's working.