"picaxe" aka pic startup time?

[Bill Martin]

Just a simple question: How long does it take a "picaxe" flavor of pic
chip to start running basic programs from power on? Thinking about a
little circuit that steals it's operating power from the load it is
driving, which is switched on/off at low rates.

thanks,
bill

 

[Bill Martin]

I couldn't say -- but it'll be more (perhaps a lot more) time than a
purpose-built system that's coded in assembly.

Is there enough power available to put the chip into some sort of low-
power mode except when you need it? That would make it come up and spin
a lot quicker.

Plan 'B' is to run the pic from a coin cell battery & sense when the
main power is available before doing any output port activity.

 

[Bill Martin]

give me a few days and I will find your answer. I suspect it is in the
order of 2 milliseconds.

low number of milliseconds would be no problem at all for this 'toy'
circuit. It just has to be fast compared to a human response time.
Thanks for your kind offer!

 

[Bill Martin]

Taking a bit longer to get to than I expected.

No problem, it turns out I may not need the PIC for version 0 of this
circuit. Found a near-perfect part from Supertex, HV7100, for speed
control of dc brush type motors. It drives a high side P channel mosfet,
which is just right for my purposes. still curious how long a picaxe
part needs to get going, but no urgent need to know. Still interested
for a possible more advanced control version of my circuit, but that's
only if there is actual interest in the simple version.

Thanks again for offering to help out a bit!
Bill