Nano with 19MHz clock, possible?

hello there,

[edit: note frequency may 9.5mhz instead of 19mhz]

i have nano have been using today tests on i/o pulse timing.  looking specific timing decided few measurements.

what surprising, least, 2 different tests had performed seem show crystal or whatever used on board generate clock frequency cpu must around 19mhz not 16mhz.
is possible?

the first measurement timing program outputs 250khz square wave pulse.  have read other posts on site specify timing when using portb= instruction , portb|=b00100000 , like, , have inserted several of these instructions create high , low signal when measured on digital pin 13 measures close 250khz.   in fact, on 2 different meters reads 250.0khz.
on crt scope (old guy) measures close 250khz time axis not accurate trust meter readings more in case, although scope should not off more 10 percent, plus or minus.

the second measurement using short wave radio quiets noticeably when radio tuned 19.005mhz , stays little quiet @ 19.010mhz, not quiet anywhere near 16mhz nano does.  nano quiet @ 15.800mhz or that, understandable, 19mhz seems way far off.

could manufacturer (probably chinese) put in wrong crystal or resonator?

also, serial communications still work if crystal wrong frequency?


thanks.

if clock 19 mhz, bootloader , serial comms not working (unless custom software loaded on chip).

you can use crystal or resonator frequency like, long frequency within specifications (see processor data sheet) operating voltage.

the compiler has notified of actual clock frequency boot loader, other timing operation , serial communications work properly.

Arduino Forum > Using Arduino > Programming Questions > Nano with 19MHz clock, possible?

arduino