Ho John Lee's Weblog

A couple of interesting rural technology nuggets on BoingBoing:

From the PlayPump web site:

The Play-Pump is capable of producing 1400 litres per hour at 16 rpm from a depth of 40m, and is effective up to a depth of 100m. A typical hand pump installation cannot compete with this delivery rate, even with substantial effort.

The Playpumps are specifically designed and patented roundabouts (1) that drive conventional borehole pumps (2), while entertaining children. The revolutionary pump design converts rotational movement to reciprocating linear movement by a driving mechanism consisting of only two working parts.
…
To date OVER SIX HUNDRED installations have been completed, a large percentage of these installations are at primary schools. A partnership has been formed with the Department of Water Affairs and Forestry; Minister Buyelwa Sonjica has been vocal in her support and encouragement for the continued installation of this system in rural Africa.

Another link from the same post highlights the Gaviota eco-community project in Colombia, South America:

A techno-tour of the llanos shows how Gaviotas has revolutionized life here. The most significant invention is a simple hand pump capable of tapping aquifers six times deeper than conventional models, but requiring so little effort that children can operate it. In normal pumps a heavy piston must be raised and lowered inside a pipe. Gaviotas engineers realized they could do the reverse; leave the piston stationary and lift an outer sleeve of lightweight, inexpensive PVC tubing instead.

In the open-air Gaviotas preschool, the children’s see-saw is actually a pump in disguise. As they rise and descend, water gushes from a vertical pipe into an open cement tank. Over the years Gaviotas technicians have installed these in thousands of school yards, using kid power to provide villages with clean water.

Here’s a wireless hotspot based on the Voltaic solar backpack: article link (Popular Science), blog link (Mike Outmesguine)

What if you could marry the short-range power of Wi-Fi with the huge coverage areas of high-speed cellular services such as EV-DO to create a portable hotspot?

Parts List
• Junxion Box wireless gateway $700; junxionbox.com
• Verizon Wireless EV-DO PCMCIA card $100; verizonwireless.com
• Voltaic Systems solar-charging backpack $230; voltaicsystems.com

The Voltaic Backpack is a little pricey (US$229), but would be just the thing for putting together a field survey kit for building rural wireless networks, disaster assessment (e.g. post-tsunami or earthquake), or other off-grid surveying applications. It provides a small set of solar panels mounted onto a backpack, which can generate power while you’re wearing it. The panels have a peak output of 4 watts, and charge a 2200mAh battery, which isn’t enough to run a notebook computer, but is enough to keep a GPS and cell phone, PDA, or camera running from the panel, and is probably enough to run a carefully chosen wireless access point as well.

There are several different backpack sizes available from Voltaic, as well as a messenger bag, but the solar panels and battery charging systems are identical for all models.

 
For portable-but-not-quite-mobile applications, the SolarMAX 28 watt solar briefcase from Sunshine Solar actually does put out enough power to run a notebook computer (my IBM T42p draws around 15 watts on batteries, with the display at medium brightness and with wireless and disk access going). It’s even more expensive though (UK 199, roughly US$350), not including batteries.

Catching up on Abhishek Puri’s Broadband Blog, found this post referencing an old (1998) paper on setting up private ISPs in India.

Also another post regarding planned rate reductions on leased lines.

One of the long term challenges for the Kuppam i-Community program I’m working with is to make their broadband services economically sustainable, even though it serves a low-income, rural commmunity in India. While the program is making good use of wireless technology to bring down the costs of intra-regional connectivity, the cost of external internet connectivity has remained high, and has been dominated by leased line expense.

It remains to be seen whether the Kuppam program will be able to find a service provider to partner with in the region or whether it will need to form an ISP-like entity to provision and operate the network on behalf of the other community programs that are making use of the service. There have been numerous statements of intent by operators planning to provide wider access to broadband network service in Andhra Pradesh, although so far none are actually available.

One of the nuisances of installing wireless access points, VOIP phones, and other small networked devices, is the need for power in the vicinity of the device. This can be a major challenge, if you’re building a small wireless ISP using an access point on an antenna mast, which is why wireless user groups have come up with homebrew POE hacks. In the past, power-over-ethernet support has been for relatively expensive equipment geared toward commercial, large-scale installation, such as rolling out a building full of Cisco 7940 IP phones.

There are a some cheap power-over-ethernet adapters available now from Linksys and D-Link:

D-Link DWL-P200 (5V or 12V, list price $39.00)
Linksys WAPPOE (5V only, list price $39.99)
Linksys WAPPOE12 (12V only, list price $49.99)

The 802.11af standard for power-over-ethernet has been published, so products are beginning to come onto the market that can directly accept power and ethernet over a single RJ-45 connection, without requiring a power splitter at the device end. I would be happy to see all the little power cube transformers under my desk go away sometime in the near future…

Forwarded this morning from Andy Fitzhugh:

WiFi Wok and the Chinese cookware 2.4GHz repeaters (at Engadget).

As some of the comments point out, earlier versions of this appeared on Slashdot sometime last year, but the pictures with overlaid captions accompanying this writeup are quite nice.

Perhaps we can make some of these to go with the collection of coffee can antennas for the Kuppam wireless program, not sure how widely available woks or similar shaped metal pans are in India.

Not a new electronica group, but an ongoing project by New Zealander Stan Swan to make some seriously DIY WiFi repeaters out of — what else? — Chinese cookware, among other kitchen and household gadgets. Turns out cheap cooking scoops make great 2.4GHz parabolic mesh dishes. Who knew? We don’t see too many WiFi extenders with bamboo handles in the States — surely a missed opportunity for the wireless adapter market.

The original site is here.