I just submitted a new campaign to Kickstarter where I ask backers to prove me wrong. The larger story is that I think the new Orison Power System Kickstarter is destined to crash and burn like way too many others have. My campaign is an experiment to see if anything can be done before everyone looses. My past efforts to intervene in crash and burn crowdfunded tech have been painfully ineffective, so I will keep trying new stuff until I get it right!
The canonical way to set the interrupt bit on AVR is the
sei (enable interrupt) instruction, but there are many creative and devious ways to set a bit.
Before you click more, see if you can think of every possible way to set the
I bit in
SREG, then read on to see if I missed any!
There is a very slight and recoverable output voltage drop when charged LiPo cells are subjected to temperatures above about 75C.
Cells that have been subjected to under-voltage, however, show a very quick and non-recoverable drop to 0 volts when they reach about 75C.
If you are one of the (very few) people who are interested in all the details, read on!…
Last time, we experimented with spiritual blind-sending as a way to theoretically speed up SPI on AVR. While there were lots of fancy oscilloscope traces and impressive demo code, there is nothing like an actual, real, practical application to get people excited. Read on to see how much faster we can make the already highly optimized AdaFruit DotStar library with a little blind-sending action… (spoiler alert – the answer is lots more faster!)
Constantly checking to see if the coast is clear feels responsible, but it wastes cycles. Sometimes it is better to leap (or load) without looking. With a little hand-coded assembly, we can run our AVR processor lock-step with the SPI hardware and blindly dump new bytes into it at precisely the right moment. Because we don’t spend any time reading and testing status bits, we can increase the maximum throughput by more than 20%. If the prospect of screamingly fast yet perfectly safe SPI turns you on, read on…
NeoPixel strips are great when all you want to do is go in a straight line, but what about when you want to make a turn?
Here is a simple little board that makes it easy and keeps perfect spacing on both axes.