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Old 10-09-2009, 12:55 AM   #7
Kent Walters
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Kent Walters has learned how to buy an e-book online
 
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Posts: 79
Karma: 92
Join Date: Sep 2009
Location: Northern California, USA
Device: iRex DR1000S, Astak EZreader (Hanlin V3)
Unhappy Ugh...

Quote:
Originally Posted by Shaggy View Post
The opinion that it's a bad design is based on the assumption that a software bug is not the main reason for the poor performance. ...
Oh, man; You keep crediting me with ‘assumptions’ of your own creation; I have made no assumptions--let me summarize why I believe that the cap sense switches, as designed and implemented on Irex’s DR1000S, were a bad design choice:

1) (This is subjective, I know) To design a battery powered device so that it will always draw power, even when turned ‘off,’ is (IMHO) Dumb. To do this on a device that is very power hungry to begin with, and arguably underpowered, is absolutely absurd. To do such a thing contradicts anything I have ever seen in any ‘Best Prectices’ manual.

By design, the cap sense switches draw power while waiting to be touched, and, as implemented on the DR, that is whether the DR is ‘on’ or ‘off.’ Whether this is the major cause of drain or not, is, to me, a moot point; it is draining the battery, and I want to stop it.

This could have been totaly circumvented by the simple addition of an on/off switch by iRex. This would prevent power drain while ‘off,’ no matter what the cause is.

And 2) As implemented, the DR’s cap sense switches are tempermental, funtioning inconsistantly and unreliably. Sometimes they respond to a finger or hand just coming too near, and sometimes they don’t respond to an actual touch. Others have reported interferance from florescent lights, and I find that, sometimes, when working at my computer, I have to turn off the computer’s Bluetooth. I always get better performance at my couch or recliner than at my computer, but I often need to work at my computer. I will ask anyone to compare this to the functioning of a Touch Wheel iPod, which is also cap sense technology, and seems to function reliably, and as expected, no matter the environmental field variables (RF/EMI, Biorythms or phases of the Moon). It might also be noted that iPods do fully power down when ‘off.’ (Good design)

If iRex could not design better circuitry, they should have stuck with conventional switches--the device would be much more reliable, and even pleasurable to use, had they used old-school switches. Yes, again, this is subjective; who cares?

The effectivness of curbarthedog’s suggestion depends on the ability to power down the DR thru software, and the bug you refer to suggests that that is not possible at this time. His idea is excellent; anyone could do it, and without voiding warranties. However, if the bug you mention is responsible for the majority of battery drain while off, and that bug is fixed, the point is moot; I simply have no confidince that irex will fix it. If the switches are causing a significant drain, and the switches can be truly turned off, curbarthedog’s suggestion is, I believe, the absolute best way to go--for everybody. While I wait for others to do their things, though, I will install a switch.

I have nowhere made a claim that a software bug was not the major factor in power drain, as I addressed where you first quoted me above. Frankly, I don’t care what iRex has done to ‘cause’ the battery problems; iRex has sold a product with serious faults, and some of those faults were by their choice and design. I can forgive ‘bugs,’ but while I wait for iRex to fix them, I’m wasting time, money, electricity, and my battery’s life. I have spent well over $1000 on this thing so far, and it is not as reliable as a free cell-phone. You might add to my costs the fact that I bought my EZReader only so that I could enjoy the benifits of ePaper without the annoyances of the DR, on those occasions when I just want to read.

I have noted the potential of voiding warranties, and not advised anyone to do so. Each person makes their own choice, and for those who choose to hack, I offer my help, knowledge and experience.

I have determined, to my own satisfaction, that the DR (as it is today) would greatly benifit from a power off switch. While you might choose to quibble about exactly what causes the drain, or which cause is most culpable, I will solve my problem, and install the switch.

Having solved the drain while ‘off’ problem, I will use my meters, logic probes, O’scope and computer to address the possibility of replacing the cap sense switches; you can monitor the swiches power usage, if you choose; I don’t see any benifit.

Kent Walters
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