Who's good with 555 Timers?

ped said:

And I presume the output is 5V ?

Click to expand...

Yes , Logic voltages are 5V max

I edited that post, have a look

Change these two lines in Sig's code to whatever number you want for on and off cycle

Yup all the above advice is correct. Glad you got it working! It's hard to find micro/nano sized ones without the CH340.

D3 is Digital 3, yes it needs a pass transistor, especially for the Micro/Nano boards as they can only source/sink ~7mA.

Set those two lines to "3" and "6" respectively for a 3s on 3s off test run. (I tested with a 5/10, 5/15, and 5/60 split to verify performance).

edit: you can set those two variables to whatever you want (in whole numbers under 32767) as long as you follow one condition:
timeperiod must be larger than ontime.

If you want precise timing, timeperiod should be the ontime plus the offtime.

Well it's all working now..Google recommends using TIP120's as pass transistors , so I'm adopting the following circuit, as I like the idea of it being opto-isolated.



Ped