No. 2: Android running on top of a more traditional, embedded Linux kernel and distribution.
Brazil has a strong community of Linux developers, so it’s no surprise that it is the OS of choice for many embedded systems designers. What is new is the number of developers that are experiencing rising demand from their customers for Android on top of kernels and devices that aren't traditionally thought of as "Android targets," i.e. cell phones.
The ordinary Android operating environment sucks for these general use cases, because it lacks the control points and signaling features that something more complicated than a cell phone always needs.
“We used to be 100% Linux, but now it is a mix of Android running on top of a standard Linux kernel (60%), 20% free RTOS, and 20% Linux,” said Rafael Coutinho, an associate at the consulting company Phi Innovations. He points out that his customers’ customers -- dentists for example -- are saying, "I know how to use Android, and that’s what I want."
Engineers at Phi Innovations are seeing rising demand for Android on a Linux Kernel. Their "chirping bird" demo, which flaps based on signals from proximity sensors, showcases the firmís embedded systems capabilities.