Sketch lockup when using constructor with the parameters and HX711 not connected

[Petorrr]

When using the constructor to initialize the class with parameter passing, the system locks up when my sensor board is not connected. I found out that this is caused by the 'read' function that is called through the set_gain/begin calls. The while loop in that function stays there forever, thus hanging the system since the system is not yet through it's setup.

Just a proposed improvement, that will make the read more robust against 'hanging' in a loop;

byte retry = 0;

// wait for the chip to become ready
while (!is_ready() && retry < 20)
{
	delay (10);
	retry++;
	// Will do nothing on Arduino but prevent resets of ESP8266 (Watchdog Issue)
	yield();
}
if (retry >= 20)
  return (0);

[lewsut]

This absolutely solves the stuck in the while loop I was having when the scales were disconnected or failed.

[amotl]

Dear Peter,

while working on #125 in the aftermath of #123, we just added your wait-for-readyness-with-retry implementation to our spring-cleaning branch by 87727e0.

The corresponding HX711_retry_example.ino uses the new wait_ready_retry() function originally coming from your suggestion.

With kind regards,
Andreas.

[gjt211]

I think I am having the same problem using the most recent version of code. If I power up the board without the HX711 connected it locks up.

scale.begin(LOADCELL_DOUT_PIN, LOADCELL_SCK_PIN);

I can't work out how to fix this issue, it would be good if the scale.begin could timeout and return a success or fail.