In the past few years, the folks at Pine64 have given us so many delicious hardware, but to be fair, their products are for experimenters rather than consumers, so sometimes the edges are a bit rough. For example, their cluster board is a Mini-ITX PCB, which can accommodate up to seven SOPINE A64 computing modules, and they are networked as a cluster through the on-board Gigabit Ethernet switch. This is a veritable powerhouse, but it has an annoying bug because it seems unwilling to restart after being told. [Eric Draken] Set out to solve this problem, And when he finally got there, his progress made the reading time long and fascinating.
We traversed the inside of the circuit board and found a lot of information about how to generate the reset signal in the process. The ultimate culprit is the back-EMF generated by resetting the distribution logic itself, which causes the low-pull wire to never completely fall to the logic 0 area once it is pulled high. The solution is an extremely simple application of the diode. For anyone who wants to learn about the work of logic-level detectives, this is very worth seeing. At the same time, the development board itself with 28 ARM cores seems to have great potential. It is even a board we mentioned in the personal supercomputer project.