GSM/GPS based elephant tracking at The Ol Pejeta Conservancy in Kenya

Katharine Houreld has filed an AP story describing how the Ol Pejeta Conservancy, a private game reserve ranch in Kenya and Save the Elephants, an NGO dedicated to the survival of the species are using the combination of a GSM/GPS based home brew animal collar solution to track and monitor movements of elephants and other animals.

A pilot project placed an electonic collar containing GPS and GSM units on Kimani, a bull elephant who was the last surviving member of a 5 elephant group with a penchant for raiding farms to eat crops. This collar allowed park rangers to track the elephant’s movements using Google Earth / Google Maps. The project also allowed park authorities to monitor animal locations at all times and acted as a deterrent against the poaching of this important resource.

Crop raiding is a huge problem on farms bordering parks and reserves as a herd of elephants or other animals can wipe out entire crops on a single night destroying the livelihoods of the farm owners.

Ol Pejeta: Elephant

The coolest side benefit of the product though was when the project team figured out that they could create a virtual “geo-fence” and trigger alerts whenever Kimani the elephant stepped outside this virtual fence – an occurrence that indicated that he was probably on his way to a village to carry out some crop raiding.

The set up used a hardware and software solution that sends text based messages in real time with location data over GSM to park rangers whenever Kimani approaches a park fence that is close to a farm.

This is yet another great example of why the use of mobile phones continue to be the computing platform of choice in many ingenious and innovative homebrew technology solutions in Africa.

Click through the links below to articles and video about this project.

How Save the Elephants is using Google Earth / Google Maps to track elephant movements.

Video on how the solution works

Philip’s Model Plane at International ArtBots Show (Video)

“I feel good when I do these things.”

One of my favorite stories on AfriGadget has been of Philip Isohe and his hobby of making very detailed (and working) model airplanes and buses made from scratch. Earlier this year, the ArtBots Show contacted me to get Philip to create one for them that they could show at their annual show in Dublin, Ireland that is happening this weekend. The airplane will be given away as a prize at the show.

They also asked me to create a video of Philip to use at the show:

Philip with the final airplane, painted and working:

The original story of Philip, done last summer.
More images on Zoopy and our Flickr group.

Evapocooler invention for cooling camels milk in Somalia

Or How to get your camel milk to market in 40 degree C climate.

My brother Dominic Wanjihia invented this gadget which he calls Fine Lined Evaporative Cooler, for rural application in Somalia – the cooling of camels milk for transportation . He was working on a project for VETAID, Somali Pastoral Dairy Development Program – SPDDP,in Burao, Somalia June 2008. All this content belongs to Dominic who has allowed me to post it here- please seek his permission to use this content elsewhere

Cool-box design Fine Lined Evaporative cooler
Cool-box design Fine Lined Evaporative cooler

Evaporative cooling technology

The evaporative cooling concept has been used for centuries in countless applications. Cooling occurs when a fluid changes state from liquid to vapor. Put simply, evaporation. In order to evaporate, the liquid requires energy or heat. It acquires this heat energy from its immediate surrounding. As the surrounding gives up this heat, it lowers in temperature or cools.

The rate at which evaporation occurs depends largely on two main factors, the amount of heat available and the humidity in the air.

The cooler must also be shaded from direct sunlight otherwise the surfaces absorb UV heat and warms up, becoming ineffective as a cooler.

In short

Evaporative cooling devices work most efficiently in windy, dry and shaded conditions

Charcoal cooler

Everyone knows how to make charcoal fridges. After carrying out extensive tests on evaporative coolers in hot arid Burao, Somaliland, with day temperatures as high as 36OC in the shade, the charcoal would absorb ambient heat from the air and as opposed to cooling, would warm up the interior compartment.

Imagine wearing a wet thick winter jacket under the palms at a breezy beach. The jacket acts as a wetsuit and will insulate your body preventing heat from escaping.

Fine lined cooler

However, imagine wearing a wet skintight t-shirt in similar conditions. The water evaporates quite rapidly and cools your body.

I applied this concept to the cooler prototype pictured and achieved startling results. The cooler would drop as low as 15.5OC at night when temperatures averaged 25OC and maintain under 17OC during the day at average temps of + 32OC.



An elevated metal box is lined interior and exterior with a fabric. In this case I used locally available corrugated galvanized iron sheets for the container and sisal sacking fabric for lining. The upper ends of the fabric overhang in a water trough that rings the top of the cooler. Capillary action causes the water to slowly trickle over the inner and outer surfaces. A small vent keeps the interior air circulating and wind guides or tunnels direct air flow over the exterior surfaces. A low speed small solar powered fan can be incorporated in areas where there is not a constant breeze.

How it works

The circulating air in the interior causes evaporation on the wet surfaces. The necessary energy is acquired from the contents hence cooling them and is transfers to the iron sides.

Wind guides or tunnels direct an airflow over the external sides. The evaporation that occurs acquires energy from the sides causing further cooling of the interior.

Convection current system to increase water bath cooling
Convection current system to increase water bath cooling

Construction design

Cool-box with water-bath interior for rapid milk cooling application– Collection Point Cooler

Walk-in cold-room for vegetable storage

Vehicle mounted for long distance transporters

Features (Comparison to conventional charcoal coolers)

Very simple construction

Corrugated galvanized iron or GI sheets increase the surface area

Wind tunnels guide air flow efficiently over evaporation surfaces

Air flow coolers at tunnel entrances

Being galvanized, the sheets are long lasting

GI sheets are affordable and available in most rural areas

Secondhand sacking fabric is available in virtually every vegetable market

The simple capillary action dripping system replaces more complicated dripping apparatus

Convection current system to increase water-bath cooling efficiency

Cool box design with waterbath for rapid drop in temperature of milk
Cool box design with waterbath for rapid drop in temperature of milk
The design simplified
The design simplified

In hot arid regions, cooling the warm ambient air before it reaches the wet evaporation surfaces increase efficiency. Note. Setup for airflow from either direction

level coolers – achieved low’s of 16OC at ambient temp of 30OC +
level coolers – achieved low’s of 16OC at ambient temp of 30OC +
Rapid Temperature Drop Test 4 lts boiling water in aluminum milk churn placed in water-bath at 16OC
Rapid Temperature Drop Test 4 lts boiling water in aluminum milk churn placed in water-bath at 16OC

For further information and other rural development concepts and innovative designs, Dom can be reached on

mobile tel +254 722 700 530

18 year old self-taught electronics “genius” invents mobile phone-based vehicle anti-theft system.

Morris Mbetsa, an 18 year old self-taught inventor with no formal electronics training from the coastal tourist town of Mombasa on the Indian Ocean in Kenya, has invented the “Block & Track”, a mobile phone-based anti-theft device and vehicle tracking system.

The system, that Mbetsa created by combining technology from projects that he has completed in the past, uses a combination of voice, DTMF and SMS text messages over cell-based phone service to carry codes and messages that allow control of some of a vehicles’ electrical systems including the ignition to manage vehicle activation and disabling remotely in real time.

Another feature of the system is the capacity to poll the vehicle owner by mobile phone for permission to start when the ignition is turned in real time as well as eavesdrop on conversation in the vehicle.

Mbetsa is now looking for funding to commercially develop his proof of concept and bring it to the market as reported on this video carried on the Kenya Television Network earlier this year.

via 69MB.

Building The Sun – A Kenyan Videographer’s DIY project

Jim is a musician, videographer and member of the Kenyan animation trio Just-A-Band. He needed a consistent light source for his video shoots, and as he puts it…
1. the sun is REALLY powerful
2. but very unpredictable

So he decided to create his own lighting equipment from easily available components that included:

1. 2 cardboard boxes (20/-)
2. 15 bulb holders (approx. 150/- each)
3. energy saving bulbs (the 23-watt ‘cool daylight’ types – 450/- each. Ouch.)
4. a roll of aluminium foil (approx. 200/-)
5. lots of cellotape/masking tape

With the help of his friend Kevin who is an electrician, he went from this




Contrast his total cost of approximately 7000 Kenya shillings (about $113) with Tungsten lights being sold in Nairobi, Kenya for 20,000 Ksh (about $320), this is a neat DIY project that not only saved him some money, but also shows the African Ingenuity we are always excited about.

Check out more pics and the rest of his post on his blog.