Wednesday, February 2, 2011

Off the Grid in Njabini, repairs, re-engineering and all the other stuff we did last week.

This weekend was yet another learning experience for team fabfi.  Thanks to a little prodding from Paul, our most recent enabler, we made the trek out to a little agricultural town called Njabini, and we're undoubtedly better for it.

Njabini is officially in the middle of nowhere.  No internet (to speak of), regular power outages, nothing but Chinese-brand electronics (and not many of them).  If the path to development is clean water, clean power, email and Skype (and it is), then Njabini has a long way to go, but what it lacks in infrastructure it makes up for in community and cute kids.  

With the best growing climate in Kenya, Njabini is a reasonably prosperous rural town (as in more people have jobs than not, even if they don't pay much).  It also has a great, albeit somewhat competing, group of community leaders -- head of the agricultural association, head of the water board, the mayor, the director of the local orphanage -- all with a meaningful interest in finding ways to improve their little town. So why do we care?

First of all, Njabini is primed for implementing the vision of free-to-fee that I've always envisioned -- build a sustainable backbone of user/subscribers and use that backbone to support free access for surrounding residents.  Thanks to the vocal support and networking from Flying Kites Global (operator of the local orphanage) we have a whole bunch of people interested being that backbone as soon as we have the bandwidth.

Second, Njabini is HARD.  If you didn't bring it with you, you probably can't get it, and Murphy's law will apply in spades to everything you do bring (so bring two of everything).

Following from reason number two, one of the most important objectives for team Nairobi is getting them to be prepared for the unexpected.  Since we've begun deploying "node in a box", I've insisted that the team do all the installing themselves.  Making mistakes where it counts is the fastest way to learning how not to make mistakes, and during our first trip to Njabini, Nick got a hefty dose of walking the tightrope without a net. 

As it turned out, our nifty CPU power supply hack had a .5A current limitation that was only labelled on some of the supplies and went unnoticed into the first four nodes.  Even though we tried charging from a discharged battery in the lab, the city power was clean enough to let most of the supplies survive and the failures we did see were easily attributed to other circumstances.  In the field, however, we drove the batteries to the limit powering our gear while we wired up the first node, and hooking them up to the supplies on questionable mains promptly fried two supplies in a row before we realised the issue.  In any normal deploy, we'd just grab a battery charger from a local hardware store and be done, but the best Njabini had to offer were some tiny 1A universal power bricks, which Nick cleverly disassembled  and wired together like so:

This nearly worked out, except that wishful thinking got ahead of hard science and only two of the 1A bricks were used to power four devices and a switch, leaving the system a few watts short of equilibrium -- a problem that wasn't noticed until the next afternoon when the batteries cut out midway through peaking of a 2.5km link to the Flying Kites orphanage.  In the end, we were able to prove a link to FK from the center of town was possible, but weren't able to work out a permanent install before returning to Nairobi for some emergency maintenance.

While Nick and I were in Njabini on friday, Tom and John were in Mt. View installing a new node.  All was well and good on the new install except that the long-haul to Lavington disappeared, and given that the feed elements were still prototypes we fully expected that something had simply fallen off the reflector on the Lavington end. It took until Tuesday to get an engineer to let us into the Lavington tower where we found nothing amiss, and the old feed still firmly in place.  Meanwhile another power supply failure had occurred on the remote end of the link leaving Nick to scramble to find temporary power for testing that the link was A-OK. 

While waiting we replaced the old feed on the tower for good measure and got the link back up with no trouble, but were left with a pile of Mr. Fix-it for this week.  While this was all a huge pain in the tukkus, it did drive one point home for team Nairobi, and that's the value of testing and contingency planning.  Last night Nick and John spent some hours building and itemising the contents of a failsafe field kit containing all the equipment required to adapt to almost any unforseen circumstance.  We'll see how it works today when they go on a blitzkreig of node repair without me.  And let's hope that this time the fixes stay fixed for good. 


  1. Thank you so much for helping out the town of Njabini!! This is an amazing development and will surely lead to great opportunities for the community. Your work is much appreciated!

  2. Thank you for this innovative and important work in this area of the world. Having just returned from a visit to Flying Kites in Njabini, I can envision what possibilities exist now for the people in the village and beyond. Your work will create opportunities that didn't exist just a month ago and open up access for education and learning for all members of the community.

  3. You guys make me wish I had paid more attention in Physics class. I am so glad somebody was! You truly are changing lives in s huge way and I can't commend you enough for it. Well done! From the other side of the world

  4. I am very excited about the effort I saw with the connection and the excitement of being wired! Thank you so much!