hello every body
i wanna to read LED status that is Embedded on a device.
this led has 3 status:
1-Off
2-On
3-Blink
when LED blink , led turn on and off every 500 milli second.when LED is "ON" there is 2V dc between tow legs of LED.
read on and off status is easy with digitalRead().
the main problem is Blink status...
i need to read this led status with nodeMcu and determine that LED is "ON "or "OFF "or "Blink"
there is 5 LED so i prefer to use GPIO(no ADC)
how can do that?
Regards,
if you use a second LED on the first or a very low value LDR
place it face to face with your led
the output of the LDR or LED goes to the base of a FET PN7000 or some such
now you have created an opto-couplier.
if your first LED is not bright enough, you might need to get a couple op-amps and feed the output into an amp to get a strong signal.
if that is too much, then for about $2 buy a cheap mini and use the AI on that and use the DO to send your high/low/blink
@OP
I am offering the following setup which you may try and report the result.
1. LED ON; Q1 is OFF; GPIO5 = LL; LED Status is ON.
2. LED OFF; Q1 is ON; GPIO5 = LH; LED Status is OFF.
3. Check if logic level of GPIO5 toggles by measuring the ON/OFF period of Q1 usng millis() function; LED status is blinking.
Covert the above strategy into codes and check the results.
thank you dave
i use led Anode leg and wire it to GPIO pin and read High or Off
my major problem is how can determine LED is blink ?
there is no Hardware problem.I got stuck in sketch
You should answer that yourself, first. What constitutes blink?
When the LED comes on: is that blink or on status? How long to wait before determining this? What about one 500 ms on time: is that a single blink, or just a 500 ms on? If another 500 ms later it comes on again, well likely that's indeed the start of blink. You're delayed by a second now, is that OK? If it was really just a single 500 ms on: will you retrospectively want to react to that? Leave it be? On or blink reaction?