Thanks Isaac,

Most of those things I never thought of.

I know they make their own chips, so I hope they are plain and basic no=20
frills type.

I was a little worried about loading the oscillator pins, they are=20
analog and any capacitive loading on the oscillator pins might disrupt=20
the oscillator. I had planned on building my own oscillator and gating=20
the output, which would (probably) be much more technically correct.

I have yet to see the inside of the thing yet:).

Regards,

AG


On 10/02/2015 09:04 AM, Isaac Marino Bavaresco wrote:
> Arbitrarily stopping the oscillator of a microcontroller may lead to a
> host of odd behavior.
>
> Some designs may accept it well, but others may randomly stop a PWM
> signal in the 'on' state and very bad things may happen.
> The firmware may become confused by the "time lapse" and behave erratical=
ly.
>
> Also, during the oscillator re-start-up it may produce spurious pulses
> that may lead to the CPU hanging. MCUs usually have a start-up delay
> timer to wait for the clock stabilization before it starts executing
> instructions.
>
> Some MCUs have clock failure detection and may switch to an internal
> clock and do unexpected things while its main clock is stopped.
>
> And so on...
>
>
> Cheers,
>
> Isaac
>
>
>
>
>
> Em 02/10/2015 09:32, Art escreveu:
>> Hi Marino,
>>
>> What type of mouse is it???
>>
>> My mouse does an initialization when it is first powered up, drawing 30
>> mA for about 10 seconds. I'm not sure a fet across the power switch is a
>> good idea, mostly because mosfets don't like slow rising input
>> transitions and an RC time constant will make the gate voltage
>> transition horribly slow.
>>
>> My idea to defeat the oscillator after the wake up timer expires leaves
>> the mouse in a mode that consumes near zero power AND that allows it to
>> continue scanning almost instantaneously when the wake up timer
>> indicates mouse movement.
>>
>> I have some micropower comparators on order and a mess of sensors.. Time
>> will tell which (if any) method works.
>>
>> Any other suggestions?? Seriously, I appreciate any input!
>>
>> Thanks all suggestions.
>>
>> AG
>>
>>
>>
>> On 10/01/2015 08:30 PM, Isaac Marino Bavaresco wrote:
>>> I just turned my mouse off and on again, and immediately moved it. I
>>> could not notice any turn-on delay.
>>>
>>> I think that a good design could be using an N-Channel MOSFET on the
>>> negative battery wire (or a P-Channel on the positive wire) and a piezo
>>> transducer to its gate, with a very large resistor from gate to source.
>>> The resistor and the gate capacitance would create an R/C timer that
>>> keeps the mouse on for a while and then turn it off automatically. A
>>> movement would make the piezo transducer to produce a voltage spike tha=
t
>>> charges the gate capacitance again.
>>>
>>> This circuit would "harvest" energy from users movement to keep the
>>> mouse on and would not use any quiescent energy from the battery.
>>>
>>> Perhaps an external capacitor and a Zener diode may be necessary.
>>>
>>>
>>> Cheers,
>>>
>>> Isaac
>>>
>>>

--=20
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