With the help of Cambridge-based engineer, Chris Moller, who donated his time to build prototypes, onebillion created a solution with Optoma’s ultra mobile LED ML750e projector.
Jamie Stuart, Chief Technology Officer of onebillion, said: “We tested a selection of ultra mobile projectors before we chose the Optoma projector but either they were not bright enough, did not have audio out or they were not energy efficient enough”.
LED projectors use less energy than traditional lamp-based models and the perceived brightness from LED projectors can be twice that of an equivalent lamp-based model. Fortunately, Malawian classrooms are kept fairly dark to keep them cool – so the 700 LED brightness of the ML750e is just right.
Weighing just 380g, this ultra mobile HD Ready little projector, with WXGA resolution incorporates a media player, native office viewer, built-in speaker and HDMI connectivity. Projection without a laptop is straightforward using the built-in memory, a microSD card slot or USB connection.
Jamie said: “The ML70e was the most energy efficient for the brightness that we needed. As the unit needs to be powered by solar energy – it is essential we have the most energy efficient solution.”
The bright, yet low-powered LED projector was connected to a long-life battery that enables the teacher to use the unit with their class for up to five and a half hours on a single charge - enough for a whole school day. It has multiple charging options: solar power, a car battery through the lighter socket, a mains adapter or 24V DC from the solar cabinet of a oneclass learning centre.
Within the unit an Apple TV media streamer is installed. This allows teachers to use AirPlay to stream material from an iPad Mini and share this with the whole class.
The unit also has an amplified speaker system so every child can hear audio in a class.
And this is all fixed securely in a sturdy case, donated by CP Cases, to protect the whole system from the elements and regular use.
The system draws as little power as possible. Teachers only need to press on/off and the hardware works together as soon as it gets signal. The ML750e has an audio output allowing external speakers to be connected. This enables the teachers to get the additional volume needed when so many children are in the class.
As well as use within the schools, the unit can also be taken out to help communicate essential messages to isolated communities on topics such as health care, contraception and disease prevention.
Andrew Ashe, CEO of onebillion, said: “The system is portable, simple to use and durable. We are indebted to Chris Moller who designed and built our prototype.”
Chris Moller said: “The projector has to be exposed to ensure that there is uninterrupted airflow through the fans (we would have preferred to seal it inside behind a glass window, away from the children’s inquisitive fingers). As it has fans, dust and humidity remain a concern. Fortunately, we were able to make the rest of the unit relatively inaccessible.”
Both the projector and iPads are charged overnight. These mobile devices can also be updated remotely. This allows onebillion to supply new material, for example on Malaria prevention, onto teachers’ tablets from the UK. Most schools have no electricity but they do have access to the mobile network. Mobile operator Airtel donates bandwidth for these iPad updates overnight via the network.