Arduino inputs. i/0 pins
'![[Image: avr_io_current_limiting_resistor.png]](https://2.bp.blogspot.com/-DdN9Fb1TIkg/Va5KEBADRtI/AAAAAAAACyY/XZ7d3akqw_8/s1600/avr_io_current_limiting_resistor.png)
5v version of Arduino not 3v, see D1 ? do not blow up D1.
to not blow it up use R1. outside The Arduino.
over 5.5vdc is not allowed, or it burns up the inside of the CPU.
same goes for inductives kick backs, EMF and blowing up D2.
always clamp EMF at the source and not allow it to enter the Arduino pin. (be it relays or any coils of any kind, COPS, Injectors, solenoids, all make huge EMF kicks)
this is the first steps in Arduino use. do not blow it up, rule 1. but yes resistors work great here. (I like not having the 100v spike at all, best)
now the topic of using a cheap cpu as a frequency mulitplier,
you need to use the input as interrupt.
The CPU is great at division, or divide by 2, easy or a counter that counts down to say 4 and sends out 1 pulse per 4 inputted. (and wrong and backwards, no good this)
but counters do not multiply at all. they divide. 1,2,3,4 bang, we want 1,BANG BANG BANG BANG, .(x4 not div by 4)
with an Interrupt (program sketch) we can fire off one interrupt service routing per one coil firing then the routine (sub) sends 4 pulses outputted.
hitch 1:
(wasted spark engines,(cops) are like 2 cylinder engines. yah. 1:2 ratio. (I sure hope yours does not fire cylinder 1 and 4 at the same time wasted spark mode) as some do. but most those have only 2 coil packs.
I do not know any other ways with Arduino to do this, below link takes this....
https://forum.arduino.cc/index.php?topic=118649.0
NEXT UP CHIPS:
but gee, slow speed, freq multiplayer chips are sold. (or made up as set)
other ways. (look ma' no CPU no programming)
https://bestengineeringprojects.com/freq...r-circuit/
https://swharden.com/wp/2016-08-31-ics50...ultiplier/
one good thing is the output is low frequency and easy 1000s of HZ only.
and simple square waves not complex analog waveforms here needed, it is measuring the rate of COIL dwell hits. (tacho)
'
5v version of Arduino not 3v, see D1 ? do not blow up D1.
to not blow it up use R1. outside The Arduino.
over 5.5vdc is not allowed, or it burns up the inside of the CPU.
same goes for inductives kick backs, EMF and blowing up D2.
always clamp EMF at the source and not allow it to enter the Arduino pin. (be it relays or any coils of any kind, COPS, Injectors, solenoids, all make huge EMF kicks)
this is the first steps in Arduino use. do not blow it up, rule 1. but yes resistors work great here. (I like not having the 100v spike at all, best)
now the topic of using a cheap cpu as a frequency mulitplier,
you need to use the input as interrupt.
The CPU is great at division, or divide by 2, easy or a counter that counts down to say 4 and sends out 1 pulse per 4 inputted. (and wrong and backwards, no good this)
but counters do not multiply at all. they divide. 1,2,3,4 bang, we want 1,BANG BANG BANG BANG, .(x4 not div by 4)
with an Interrupt (program sketch) we can fire off one interrupt service routing per one coil firing then the routine (sub) sends 4 pulses outputted.
hitch 1:
(wasted spark engines,(cops) are like 2 cylinder engines. yah. 1:2 ratio. (I sure hope yours does not fire cylinder 1 and 4 at the same time wasted spark mode) as some do. but most those have only 2 coil packs.
I do not know any other ways with Arduino to do this, below link takes this....
https://forum.arduino.cc/index.php?topic=118649.0
NEXT UP CHIPS:
but gee, slow speed, freq multiplayer chips are sold. (or made up as set)
other ways. (look ma' no CPU no programming)
https://bestengineeringprojects.com/freq...r-circuit/
https://swharden.com/wp/2016-08-31-ics50...ultiplier/
one good thing is the output is low frequency and easy 1000s of HZ only.
and simple square waves not complex analog waveforms here needed, it is measuring the rate of COIL dwell hits. (tacho)
http://www.fixkick.com