Strange problem with HC-SR04

[onlize]

I am trying to use ESPEasy with HC-SR04 and I have some strange problem.

If I connect everything and start the device, it comes up for a very short period of time and, I think, it reboots. It keeps rebooting. I see 5-10 ping and 5-10 ping time outs. It keeps doing this.

I found the fix, but it I need something better. If I want to fix it, I have to disconnect Trig and Echo pins and connect them when device is up and running. After that, everything works until I reboot it next time.

I followed this article and used option with resistors: https://www.letscontrolit.com/wiki/index.php/HC-SR04

Any ideas? I have two nodeMCU devices and both do the same for me. Is it a bug with HC-SR04?

Thank you.

[budman1758]

What GPIO's are you connecting to? Can you provide a diagram of your setup?

[onlize]

Thank you for your reply. In the end, I was not able to connect at all, so I had to reset and reflash it. Everything works now.

[ssathya]

I have a similar problem. Soon after I boot my Wemos I get a good reading but subsequently, my device is not able to measure any readings. Here is the log:
SR04 : Distance: 132.17
WD : Uptime 1 ConnectFailures 0 FreeMem 18128
SR04 : Distance: No reading!
Host unreachable: 40992557
WD : Uptime 1 ConnectFailures 0 FreeMem 17944
SR04 : Distance: No reading!

I did try the the following sketch and it works okay.

Code: Select all

#include <NewPing.h>
#define TRIGGER_PIN 2
#define ECHO_PIN 4
#define MAX_DISTANCE 1000


NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE);

void setup(){
  pinMode(LED_BUILTIN, OUTPUT);
  Serial.begin(115200);
}
void loop(){
  digitalWrite(LED_BUILTIN, HIGH);   
  delay (300);
  digitalWrite(LED_BUILTIN, LOW);
  Serial.print("Ping: ");
  long median = sonar.ping_median(10);
  float medianFtCompute = (float)median/(148.0 * 12.0);
  float medianInch = sonar.convert_in(median);
  float medianCm = sonar.convert_cm(median);
  Serial.print(medianInch/12.0);
  Serial.print(" ft ");
  Serial.print(medianFtCompute);
  Serial.print(" ft computed ");
  Serial.print(medianCm);
  Serial.println(" cm");
}

[onlize]

This problem is back. It seems like it starts when I connect HC-SR04.

I use, as suggested in that document, GPIO-13 and GPIO-12.

Also, I have PCF-8574A attached to this device.

Any ideas?

[toffel969]

This problem is back. It seems like it starts when I connect HC-SR04.

I use, as suggested in that document, GPIO-13 and GPIO-12.

Also, I have PCF-8574A attached to this device.

Any ideas?

Could be a power problem. What is your power supply? Are the cables thick enough?

Hypothesis:
Sending an US-ping takes quite a bit of power, so does WiFi. Maybe, when both cooincide --> instability of 5V power supply.

Suggested remmedy:
Beef up PSU, maybe just a cap over 5V to GND and see if behaviour persists.

[onlize]

Thank you for the suggestion, but I tried different PW. I have a few Power Supplies that I use when I play with Raspberry PI devices.

[Shardan]

Can you test an older firmware like the R120 or R147?
Just to see if it is a problem with hardware or with software.

I've tested the setup in the wiki for several days without problem before publishing it with a Mega version, but that's a while ago.

[onlize]

Sorry, but it is already in place and working. I do not want to start making changes now.

It restarts multiple times in the beginning, but after that everything seems to be working.