Re:Hands-on with the PocketBeagle: a $25 Linux computer with...
by hinkley on Monday December 04, 2017 @03:26PM
(#15847143)
You get compression at the low end. It’s not especially cost effective to maintain manufacturing capacity for a bunch of similar designs. If I can make better margins on a $5 part than I can my $4.25 part I’m going to be really tempted to shut down that line and make more of the other or a higher margin chip.
That’s part of the story with Linux on BIOS. Motherboards started shipping with EEPROMs that were 2-4x larger than the BIOS would ever get, as big or bigger than typical rescue disks.
A few months ago, I started on a project that needed to read an input signal, do some trigonometry on it and update some I/O at a 30kHz update rate. The kind of thing a DSP could handle in its sleep, but I don't have DSP tools and it wasn't worth the investment.
Since a standard Arduino Uno wasn't fast enough to do the math, I built a table of precomputed sines & cosines, scaled to the output signal.
But then we needed 12 bit analog input. Since the Cortex M0 on newer Arduinos (Due?) has a 12 bit A/D and is much faster, I could now drop my precalculated table and do the math on the fly.
But the ADC in the M0 turned out to be crappy, so I ditched it for an off-board 12-bit ADC and went back to the Uno and the sin/cos tables.
Had I not been concerned about latency and startup times, I'd have used a Raspberry Pi with an external ADC or a Beaglebone right out the gate and probably finished the project inside a week. I'm selling the hardware with enough margin that the extra cost doesn't matter to me and it matters even less to my customer.