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A couple of things 43s related
03-02-2015, 06:10 AM
Post: #24
RE: A couple of things 43s related
(03-01-2015 01:37 AM)BarryMead Wrote:  
(02-26-2015 07:27 PM)jch Wrote:  Marcus,

Maybe a Teensy 3.1 could do the job ? It's tiny, quite cheap, low power and have horse power.

I have one of these Teensy boards. I wrote a few test programs on it to confirm that the USB interface is fast and reliable, then I just put the thing into my toolbox for future projects. I don't remember that it was particularly low power, except in sleep mode, but it certainly is powerful. It uses an ARM Cortex-M4 MK20DX256 32 bit processor running at 72 MHz. At that clock speed it will use quite a bit of power unless it is sleeping. With all internal peripherals turned on it consumes about 31 mA operating, and you need to add any current consumed by driven outputs to that total. While it is sleeping with all internal peripherals turned off, it consumes .61 mA. So if you operate one of these with batteries, you would want to use AA cells not coin cells. With 2500 mAH AA cells you could get about 80 hours of program running time, or about 1/2 year of off (Sleep) time.

I'm definitely going to play with one of these soon. I am suspicious that this 'teensy' board will have speed stepping or at least a way to reduce the main clock (the WP34s 'SLOW' mode) which will reduce the current drain; most of the time we really don't need the ARM to be running so dang fast that it sucks our batts dry...
i don't mind using the ubiquitous 9v batt, nor lithIon... doesn't have to use coin cells (that seems to be an expected paradigm now with HP calc users.


Kind regards,
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Messages In This Thread
RE: A couple of things 43s related - jch - 02-26-2015, 07:27 PM
RE: A couple of things 43s related - jch - 02-27-2015, 08:48 PM
RE: A couple of things 43s related - MarkHaysHarris777 - 03-02-2015 06:10 AM
RE: A couple of things 43s related - jch - 03-02-2015, 09:09 PM

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