One Step Forward, Two Steps Back

8/24/2012
Goodbyes are so hard.

On the students' last official school day with me, I taught my third enrichment science class for the Form 3s in which we set up a zinc-copper electrochemical cell. They usually do not do practical experiments in class; even the Tanzanian physics and chemistry teachers hadn't seen a real live electrochemical cell before. They were pretty amazed.

From left: Obedi, Some Random Student, Lota, and Dickson

Lota and Edu watching the teachers vs. teachers volleyball game after school

Jamani, I will miss these guys. I love them so much.

8/21/12

Today I got really worked up, and then blew off a lot of steam.

The power is out in the Orkeeswa science lab and computer lab, because something is wrong with the solar system. (And if you're thinking, "Woah! The entire solar system?!?!" don't worry- I mean the electrical system at the school.) On Saturday, a group from Engineers Without Borders that had come to plan Mungyere's solar power came to Orkeeswa to do a routine check-up on the system they'd designed and set up there. They'd taken the Mate (the programming interface) for the system and scrolled through the settings, checking to see if everything was okay, which they determined it was. This morning, when teachers began to discover that the power was out, a rumor spread that the engineers had made the system not work on purpose in order to sabotage the school. It was so upsetting to think that there was so much bad blood that they could come to such a conclusion; it is hard to write about even now.

All of the volunteers with engineering backgrounds who weren't teaching at the time (me, Jessica, and Andy) were ordered to fix the problem so they wouldn't have to call the engineers back. None of us are electrical engineers; none of us knew very much about how the system worked, and we understood just barely enough of the manual to scroll through the settings and determine that nothing seemed obviously wrong. The error messages were: "Battery voltage too high" and "AC output short." But I had no idea what to do about the battery voltage being too high, and we also tried turning off electricity to each of the rooms and trying to figure out where the short might be, to no avail. In conclusion, we each wasted about three hours of our lives because of pride and prejudice. People eventually became sane again and agreed to let Andy email Jeni, the main solar expert on the team. But it was crazy for a while.

Then I was called into a meeting today to talk about Internet policy; it's a conversation that has been delayed for about two weeks now because of scheduling issues. I expected a serious discussion about starting to get funding for the data plans from Airtel, and what the Internet would be used for in the computer lab, and by whom. Instead, the immediate resolution reached was to delay these decisions until a longer-term volunteer could arrive to manage the use of the computer lab and take over computer classes. Until then (which might be two months from now or later), neither students nor teachers will be able to access the Internet. All of these educational resources IEFT had been so keen to have will remain floating around in the tubes for a long while before being pulled into existence at Orkeeswa. Bummer.

After that, I didn't really want to talk to anyone, so I went into the science lab and threw all of my energy into making lab safety posters for the following two hours. It was extremely therapeutic.

Very proud of my lab safety and fire extinguisher posters. Credit due to Jessica for all the rest.

I am in the process of writing up the documentation for the Internet system, a very short and clear page that can be put up on the wall next to the router. Will have this done by the end of the week.


8/22/12

The shelf for the wireless router is now up.

What will go on the shelf when the system is all set up (minus the USB modem and coax cable)

8/19/12

Today is Eid! And so is tomorrow. Unfortunately, that means Orkeeswa and most businesses will be closed until Tuesday. With only 10 days left here, time is getting a little short; I'll have to test the new USB modem with the wireless router on Tuesday in both the computer lab and the LBH, and then hopefully go to Sound & Vision in Arusha on Wednesday to purchase another 3G router for the computer lab. (The Internet speed turned out fine.) On that day, I should also go to the Airtel store to find out whether it is really true that they have a time-based monthly data plan for 30,000 shillings, which I've so far only seen on their website. There is still so much to be done! But at least I know roughly what it is.

I encountered an interesting problem a few days ago: I stopped being able to recharge the Airtel sim card from the unlocked Huawei E160E USB modem (with the external connector) that I'd ordered off ebay UK.

(Not sure if I mentioned this before, but I had that and the crc9 to N-male pigtails sent to the DHL office in Arusha, where I picked them up with absolutely no problem. This was probably helped by the fact that it was a very small package, and my dad officially listed the item as being valued at $5 so that customs would not try to confiscate it.)

I believe I had been able to recharge it fine at least once before, and was very confused. I thought it might be because the firmware on the Huawei modem was somehow not communicating with the sim card correctly, or maybe the Airtel interface for connecting to the Internet wasn't communicating with the towers properly. The effect was very distressing, because when I ran out of Internet credit at the school, I was not able to recharge it with the credit voucher I had by SMS-ing the recharge code through the interface (*104*voucher code#). Even the balance-check code (*102#) was not working. At first I feared that Airtel might have figured out a way to block unlocked modems, which would have made it difficult to make the connection as stable as with the specially-ordered pigtails.

I now think it was a combination of the firmware and interface. I tried both codes with an old-model Huawei E173 proprietary Airtel modem (gotten by Brandt at Shoprite), and the slightly different Airtel interface that had come loaded on it. The *102# code worked fine, but the recharge (*104*...#) did not go through. The error message was: "Receive: Failed" or sometimes "Receive: Timeout." Then I tried the recharge with the sim card in the new model of USB modem sold by Airtel, a ZTE MF190 loaded with the latest interface software. It didn't work with that particular voucher I had (which I think was just bad) but I ran all these tests again with new vouchers and found that the recharge worked fine in the new modem with the new interface. The new interface doesn't work with other modems; I'd been using the older interface with the unlocked Huawei modem. Maybe the older software also shouldn't recognize other modems either, and it just does so because the unlocked modem is also from Huawei. I'll have to try different modems with different interfaces to gather more information about this problem; if the other volunteers also start having trouble recharging their sim cards with credit (as most of them use older modems with older interfaces), it'll be evidence that Airtel is trying to phase out the older interfaces in general, so the school will have to use one of the new modems just for credit recharging (which will be annoying, but not impossible). If we manage to get the unlimited monthly plan for the school, this will only have to be once a month.

8/18/12

The signal reception at the current height of the antenna turned out to be fine (consistently 3 bars HSPA). Perhaps I was being paranoid... but then again, maybe I could have gotten 5 bars.

8/17/12

I suppose the setup of the antenna at the school computer lab/library building is now finished, but I'm not quite happy with it. The reason is that the antenna is mounted not quite at the height of the peak of the roof, which may well be too low to get a very fast 3G connection (HSPA/HSDPA as opposed to W-CDMA). During testing, I found that the height at which I started receiving HSPA/HSDPA signal was around two feet above the peak of the roof. I had assumed when we started building that since our 20-ft pole had been more than high enough to reach the peak at the Laguna Beach House, it would be the same for the other building. The buildings look similar enough; they are both one-story concrete boxes with corrugated tin roofs. But as it turns out, the computer lab building's roof is steeper (which I noticed briefly during testing but didn't think it important), and the wall under it is slightly taller, so where we wanted the antenna is slightly higher than where we could safely mount it with proper lightning protection.

I should have measured beforehand how high the pole would come up above the roof, but instead I rushed ahead with construction without checking, which was foolish. If the Internet in the computer lab ends up being significantly slower than at the Laguna Beach House, I will take pains to redo the entire setup, probably to the great frustration of Elifuraha the fundi. But it should not take more than three school days- the first day to remove the grounding system and the new concrete base for the antenna pole, and the second two to either extend the antenna pole by splicing on another piece of pipe under it, or cutting down the pole and re-mounting it atop a small, high-up ledge on the side of the building that I hadn't previously considered as a good base for the pole. After looking at it a second time (and considering that the Internet might be half the speed it could be because of the missing height), I think we could make it work.

I'm glad that we at least got 2 feet of extra height because I noticed my mis-assumptions when I went to mount the antenna. We had already attached the grounding wire to the pole (a 20-ft long, 2-inch diameter black pipe) before putting it through the hole we made in the tin roof. (The choice of location for the hole was at least obvious, because there was only one place on the edge of the roof that was not covered with plaster.) There was a limited length of ground wire at school- just a little over 20 feet (the piece that was left over from the 50-ft piece we had cut for the LBH ground). So at the time I thought it would be fine to raise the antenna just a few feet by placing cinderblocks underneath the base and then turning that makeshift base into a big concrete block at the end- then it would still be possible to use that piece of ground wire. In the end, we took a piece of pipe from the storage container that had been left over from the LBH installation, cut it to about 2 feet, cut one end into four pieces which we splayed apart, stuck the bottom of the antenna pole inside it, and put concrete in the bottom of the 2-ft extension.

Mounting the antenna on the computer lab/library building with Elifuraha the fundi

Elifuraha mixes a bucket of sand, a lot of "aggregate" (the rocks), composite cement mix, and a lot of water to make concrete. I tried to help, but it required more strength than I have. :/

Concrete poured into the hole at the bottom of the pipe. We later bordered it with a box so the concrete block would be nice and square. The blue pipe is the conduit for the grounding wire, which runs down inside the antenna mounting pipe.