Hi Curtis,
In the next few weeks I should have some feedback from my first
users/clients, they have one unit with them at the moment for experimenting
and getting familiar with. They will be used in some indoors and some
outdoors environments, for only 4 or so hours at a time. Responses will
probably be 'dumped' when they get back to base at the end of each day.
Your engineer friend makes a good observation, but aside from the very low
standby consumption, I think it is the low-powered nature of the processor
and so on that also helps. I haven't yet tried disabling all the background
operations or even underclocking the processor. this link
http://forum.xda-developers.com/showthread.php?t=1933615 . I think you
are right about the non-linear nature of the battery, the last 20% or so
will drop off faster than you would think.
I have added a USB keyboard to one, this link
http://forum.xda-developers.com/wiki/BN_Nook_Simple_Touch/USB_host_mode#Utility_software
- it could be useful in cases where lots of text input is required but at
the same time could reduces the battery life further running the 'host'.
The exact key mapping may be a bit different, for instance the numpad keys
were not recognized, and the slow refresh rate means it is difficult to
keep a high typing speed up without errors. Also using the
up-down-left-right keys didn't seem to navigate the display, eg move
through questions, but there is probably a clever way around this somehow.
The USB function could possibly be used to add a 3G/4G dongle - for
occasional uploads while in the field? It is probably more sensible just to
use a phone to set up a wifi hotspot to do this. Or I suppose you could use
USB to backup data locally, again, probably easier to just take out the
microsd card.
The internal battery (I think about 1500mah) seems relatively easy to
change out for a higher capacity one or when it stops holding a charge. A
bit more elegant than adding external batteries. A 3000mah one I have seen
for about £30, almost as much as the device, but would probably double all
the times we are talking about.
You do hear problems with the touchscreen unfortunately. If it is not
something easily fixable like grease or dirt blocking off the sensor, then
the unit loses a lot of it's functionality! I do not really know much about
touchscreens, although it is some kind of basic infrared grid not a
capacitive one like a higher spec device. Maybe that makes it easier to
break the touchscreen?
Have you seen devices like Onyx Boox? This is e-ink and runs Android
natively, more recent version than the Nook can handle. There is even one
model with quite a large 10" screen. It is a bit more expensive (maybe
£10-20 for the 6" one) but looks like a good product. Also another e-reader
to root android with appears to be the Sony PRS T2.
Finally I tried to estimate the environmental impact of it, based on the
various statistics being thrown around (some very high, some low) about
paper books vs e-books. I estimated that once you had filled in about
10,000 questionnaires you would have saved enough paper to offset the
energy used in the creation of the device. Also when doing paper forms, the
tendency is to print way more than you actually need. You could also use it
to store big manuals, textbooks and things too, that would very quickly
save a lot of paper.
I am rambling on but I am really keen on this system and glad to hear
others are doing the same!
Thanks
Rich
···
On Tuesday, April 21, 2015 at 11:41:41 AM UTC+1, Curtis Broderick wrote:
>
> Richard,
> I finished my test. 30 minutes of entering responses into forms (a medium
> length form) with WiFi off, dropped the battery from 92% to 85%. Of course,
> some people enter a form, put the nook in their pocket, walk 10 minutes
> then interview another household, but that sort of near-zero "in-between"
> time consumption one cannot say. An engineering friend of mine told me that
> the device consumes as much energy as a regular tablette when it is
> updating the screen. Of course, the screen only updates when you tap on it.
> It can sit inside a handbag and consume near to zero energy while in sleep
> mode or just not being touched . I am going to do another test when the
> battery is down to about 20% since I don't think that the discharge is
> completely linear. But I like your 30 minute testing method. After the 30
> minutes, I durned on Wifi, and sent 5 of the 9 forms that I had filled in.
> It was still at 85% when I checked the battery afterwards.
> Curtis
>
>
> 2015-04-21 12:06 GMT+02:00 Curtis Broderick >:
>
>> Hi Richard,
>> Sorry to get back to you so late. I was giving an ODK training all last
>> week. Was using the nook to show form changes quickly because it can be
>> connected as a external USB device in normal mode not MTP. I like your
>> ideas about testing the autonomy. I am actually doing a little test now. Do
>> you have any of these converted nooks in the field. I would be very
>> interested to know how that works out in reality. No GPS is kind of a
>> bummer, but compared to a regular tablet, the Sun factor, battery life, and
>> reggedness eally put the others to shame. Talk more later.
>> Curtis
>>
>>
>> 2015-04-14 9:32 GMT+02:00 Richard Fletcher > >:
>>
>>> Hi Curtis,
>>>
>>> Just wanted to say this is what I've done as well except with the
>>> non-Glowlight nook. It's cool that you have compiled it into one image and
>>> made available for people. I followed the instructions here:
>>>
>>>
>>> http://www.makeuseof.com/tag/hack-your-nook-simple-touch-into-a-super-e-reader-in-three-easy-steps/
>>>
>>> This seems to add a USB hostmode (for adding an external keyboard) and a
>>> fastmode for the screen - both of these would drain extra power if I
>>> understand so despite the functions still might not be desirable
>>>
>>> I have got three rooted Nooks running ODK at the moment, only done
>>> limited 'field testing' with them so far. I will be handing them over to
>>> other researchers or volunteers to use for the most part.
>>>
>>> As long as the wifi is off, battery life seems really good. I did a
>>> rough test of continually inputting responses for 30 minutes - this dropped
>>> the battery life from 100% to 97%. If I recall about 25 were completed in
>>> this time (a relatively short questionnaire) but lets round to 30 for
>>> simplicity. So you can get about 10 minutes/10 responses per 1% of battery
>>> life - theoretically 1000 responses or about 16 hours? I have found the
>>> Nook goes into 'warning, charge me up mode' at around 15% so I would
>>> estimate about 14 hours of continual, non-stop inputting? If you used it
>>> half an hour a day it would last a month as you suggest.
>>>
>>> It's still very impressive! Even if you do need more power, very cheap
>>> external USB batteries are available that would extend this lifespan many
>>> many times! The nook internal battery is about 1500mah - I picked up a
>>> (supposedly) 10,000mah battery for around £20. You could probably add a
>>> solar panel or something too if you really wanted!
>>>
>>> There are probably other ways to under clock the device and turn off
>>> other unnecessary background applications too to save power
>>>
>>> Sorry to ramble, it's exciting to hear other people doing the same thing!
>>>
>>> Rich
>>> @rfletch0
>>>
>>>
>>> On Thursday, April 9, 2015 at 5:11:07 PM UTC+1, Curtis Broderick wrote:
>>>>
>>>> Hey all you ODKers,
>>>>
>>>> Am happy to let you know that we have created a nice little image file
>>>> to convert a nook e-reader into an Android tablet and are sharing it with
>>>> whoever would like to use it. We have a simple web-based data collection
>>>> tool called Wepi and were very happy (and thankful to the ODK team) to have
>>>> incorporated the mobile data collection aspect into it. You can use the
>>>> device with any aggregate not just Wepi.
>>>>
>>>> You can find the conversion instructions (and .img file) at
>>>> www.wepi.org
>>>>
>>>> If you don't need GPS, photos, or sound in your forms and the following
>>>> points are important for you, check it out : )
>>>>
>>>> - perfect visibility in strong sunlight
>>>> - battery autonomy measured in weeks
>>>> - rather rugged device, screen doesn't crack (it's plastic)
>>>> - not very interesting to steal this device
>>>>
>>>>
>>>>
>>>> --
>>>>
>>>> *Curtis BRODERICK*
>>>> Wepi Project Manager
>>>>
>>>>
>>>> ---------------------------EpiConcept---------------------------
>>>> Systèmes d'Information en Santé
>>>> Health Information Systems
>>>> 47, rue de Charenton - 75012 PARIS
>>>> Tel : +33 (0)1 53 02 40 60 Fax : +33 (0)1 53 02 40 62
>>>>
>>>> --
>>> --
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>>
>>
>>
>> --
>>
>> *Curtis BRODERICK*
>> Head of technical training and user support
>>
>> ---------------------------EpiConcept---------------------------
>> Systèmes d'Information en Santé
>> Health Information Systems
>> 47, rue de Charenton - 75012 PARIS
>> Tel : +33 (0)1 53 02 40 60 Fax : +33 (0)1 53 02 40 62
>>
>>
>
>
> --
>
> *Curtis BRODERICK*
> Head of technical training and user support
>
> ---------------------------EpiConcept---------------------------
> Systèmes d'Information en Santé
> Health Information Systems
> 47, rue de Charenton - 75012 PARIS
> Tel : +33 (0)1 53 02 40 60 Fax : +33 (0)1 53 02 40 62
>
>