How would a software engineer, a dance teacher and a helicopter pilot set out to help the Third World? In the case of William Weatherholtz from Utah and the rest of his seven-strong team it was through an entry to Inveneo’s ARM Micro-Data Center Design Challenge.
The aim of the competition was to design a solar powered micro-data centre capable of withstanding extremes of heat, dust and humidity. Entries came in from across the world, with teams comprised of three to seven people.
The winning design is a self-contained weather monitoring station based around the Banana Pi single board computer (SBC) that uses an an ARM-based processor. It’s powered by an absorbent glass mat (AGM) battery, charged in around four hours from the roof-mounted solar panels. Once fully charged, this provides enough backup power to sustain the device for up to three days.
The data centre is housed in a tough aluminium casing, which also acts as a heat sink, helping the electronics inside to withstand ambient temperatures of over 50oC. This task was made harder by dust ingress, which meant the casing had to be almost completely sealed.
“This design challenge was essentially an enclosure and heat problem. The concerns with racking, powering, and layout of the data centre components are relatively trivial compared to determining how to prevent heat issues,” said Weatherholtz.
Finite element analysis was used to determine the best layout of the components within the case. The two main heat sources were found to be the processor and RAM, so these were placed at the bottom of the device.
“I really can’t overstate the importance of thermal analysis in projects like these,” said Weatherholtz. “For us, making a low thermal-resistance path out of the case was a main design consideration. Everything centred on where the heat was generated and how we got it out.”