Hi Cory, I don't know anything about point of sale equipment, but here are some thoughts about the power side of things.
What are the power requirements of the scale and printer? My intuition is that they will account for a good chunk of your power consumption. I'm a bit doubtful of the smart phone solution: Phones achieve long run times by being very power efficient, but that goes out the window when you have to power an external device. I would think lower tech: It's hard to get long battery life out of something you carry in your pocket, but this doesn't sound like it has to be all that mobile. Lead-acid batteries are very cost effective and easy to source/repair/replace all over the world. A car battery holds about 1200 watt-hours, while an iPhone battery holds about 5. Solar doesn't need to be nearly as expensive as the Brunton device, unless you need to roll it up and stick it in your backpack. A 5-watt panel can be had for around $50, with perhaps another $50 for charging electronics. Good luck, Eric Thus spake Yaw Anokwa (yanokwa at gmail.com): > depends what you consider reasonably priced. a solar charger than can > keep a netbook happy will be in the $300-600 range > (http://www.brunton.com/product.php?id=256). much easier to get two or > three batteries per machine that folks can send to the market to get > charged. netbooks assuming low lcd use and little radio use should > last a day. > > the phone solution is probably your best bet as far as being able to > ruggedize and support the features you want. > > On Thu, Dec 10, 2009 at 23:56, Bush, Cory <CBush at tns.org> wrote: > > Thanks Yaw and Clint. ?Price point is certainly a concern, especially given > > the fact that these will be used for smallholder cooperatives which will > > require multiple devices per group. ?I think that Symbol is a bit expensive > > for these purposes, we're certainly more focused on appropriate smartphones. > > > > Netbooks could be an option, but we would need some sort of protective > > skins and power/charging is another concern as these villages are off the > > electricity grid. ?Given your understanding of the power consumption of > > netbooks, do you think it would be realistic for them to operate for 6-8 > > hours per day while also powering a scale / printer? ?Are there reasonably > > priced solar options which could provide a sufficient power source while > > the sun is shining? > > > > Thanks again for the thoughts. > > > > Cory > > > > > > -----Original Message----- > > From: Clint Tseng [mailto:cxlt at cs.washington.edu] > > Sent: Thursday, December 10, 2009 8:52 PM > > To: Yaw Anokwa > > Cc: Bush, Cory; change > > Subject: Re: [change] Digital scale / transaction recording device > > > > I'm not sure about the scale part, but I was down at Marination Mobile > > the other day and they had a really slick looking point to sale app on > > an iPhone that talked wirelessly to a small battery powered receipt > > printer; might be a better price point and form factor depending on > > whether you can get it unlocked, etc. > > > > ?Clint > > > > On Dec 10, 2009, at 9:35 AM, Yaw Anokwa <yanokwa at gmail.com> wrote: > > > >> for ruggedized mobile devices of the kind you are describing, your > >> best bet is http://www.trimble.com or http://www.symbol.com. > >> > >> you could also try a netbook with a gsm slot paired with a usb receipt > >> printer and a usb scale would get you 90% of the way there. the > >> netbook could likely power both of those devices. you could likely > >> swap the netbook for a smart phone (say android running open data kit) > >> but phones with usb master support are hard to find... > >> > >> On Thu, Dec 10, 2009 at 01:18, Bush, Cory <CBush at tns.org> wrote: > >>> Greetings all, > >>> > >>> I?m trying to scope a solution for coffee cooperatives here in Rwa > >>> nda that > >>> will enhance transparency into the sale of coffee at small > >>> community-level > >>> collection points, and would appreciate any thoughts / ideas / device > >>> recommendations. ?Basic requirements would include: > >>> > >>> - ? ? ? A digital scale capable of weighing up to 30kg > >>> > >>> - ? ? ? Ability to capture transaction information including: ID#, > >>> price per > >>> kilo, KG delivered, coffee grade, collector ID#, payment type (cash/ > >>> bank) > >>> > >>> - ? ? ? Ability to generate a paper receipt > >>> > >>> - ? ? ? Ability to transmit transaction information in real-time if > >>> mobile > >>> data network available or store-and-forward batches if data network > >>> unavailable > >>> > >>> - ? ? ? Ability to generate daily/weekly/monthly reconciliation or > >>> summary > >>> reports > >>> > >>> - ? ? ? Ideally the scale, transaction device, and printer would be > >>> integrated, but not necessary > >>> > >>> - ? ? ? Device(s) should have low power requirements, and be able to > >>> function for a full day between charges or be powerable via standard > >>> batteries. > >>> > >>> - ? ? ? Device(s) should be rugged enough for use in rural settings > >>> > >>> Thanks in advance for any insight, > >>> > >>> Cory > >>> > >>> Cory Bush > >>> RW Mobile: +250-788-309287 > >>> > >>> RW Office: ?+250-252-580414 > >>> Skype: corycbush > >>> > >>> _______________________________________________ > >>> change mailing list > >>> change at change.washington.edu > >>> http://changemm.cs.washington.edu/mailman/listinfo/change > >>> > >>> > >> _______________________________________________ > >> change mailing list > >> change at change.washington.edu > >> http://changemm.cs.washington.edu/mailman/listinfo/change > > > _______________________________________________ > change mailing list > change at change.washington.edu > http://changemm.cs.washington.edu/mailman/listinfo/change -- Eric W. Anderson University of Colorado eric.anderson at colorado.edu Dept. of Computer Science phone: +1-720-984-8864 Systems Research Lab - ECCR 1B54 PGP key fingerprints: personal: 1BD4 CFCE 8B59 8D6E EA3E EBD5 4DC9 3E61 656C 462B academic: D3C5 D6FF EDED 9F1F C36D 53A3 74B7 53A6 3C74 5F12 -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 197 bytes Desc: Digital signature URL: <http://changemm.cs.washington.edu/mailman/private/change/attachments/20091211/8b9099c7/attachment.sig>
