I second Frank's idea to export just one default F_CPU, F_PLL and F_BUS to quickly create a first compatibility status with most libraries.
In a second step, when the clock control object is up and running and allows dynamically changing all clocks on the fly, that could be the moment to refine the work on the libraries and implement this new clocking API for the T3 series, too.
Yeah, that does seem like the most reasonable way to go.
This beta isn't going to be like the last two (LC & 3.5/3.6), where many things worked from the beginning. The core library still needs a ton of work and almost no libraries are working yet. This beta is going to be much more of an adventure! But I believe I at least have the bootloader & hardware reliable. It does have the 15 second button pretty to wipe the flash, and that erase is done with JTAG boundary scan (the IMXRT is held in reset mode) which hopefully gives us a way to recover when/if things go really wrong.
My hope is we'll be able to mostly move away from using F_CPU. But in some places it may still be unavoidable. The FlexPWM and QuadTimers in particular end up running from the IPG clock, which is an integer division of the ARM clock. I did implement analogWriteFrequency() for those, based on whatever the clock happens to be at the time you call it. For other libraries using those timers, still not sure what to do yet...
The Teensy 4.0 First Beta Test thread
https://www.nxp.com/docs/en/application-note/AN4579.pdf
A nice appnote about heat and heatsinks on IMX 6. It gets warm, too.
Last edited by Frank B; 12-27-2018 at 07:15 AM.
Took Frank's link to US and ordered one of these as I picked up something else from Amazon $2.83 : Homyl Copper Slice Heat Sink Heatsink Cooler
One note on this or another of these items - once applied it will likely take the chip off with it when trying to remove it.
the smallest fans on fleabay are 15x15 at 5v, dont bother with the 10x10 3.3v ones theyre 5x the price... hehe
Wow, I had no idea graphite conducts heat as well as copper only in X & Y (lateral) dimensions but not Z (vertical). Pretty amazing!Originally Posted by Frank B
I didn't even know that it was used for heat sinks. It's a pretty amazing material.
Maybe we can implement a critical-temp shutdown.
The document mentions 100°C as "critical", 90°C as "Hot".
Perhaps the shutdown should disable all pins, too, so the user can use appropriate pullup/pulldown resistors to stop motors etc.
Edit: "Hot" could be an event...
Last edited by Frank B; 12-27-2018 at 11:18 AM.
Post #169 describes SDK example that monitors chip temperature and shuts down if "too hot". (ch 53, temperature monitor)
Was starting to look at it the registers for the tempmon in the imrtx.h file is on the todo list.
EDIT: Also it appears to need the octop registers, only needs octop->anal1 for calibration data
Last edited by mjs513; 12-27-2018 at 02:10 PM.
What is the value of hot_temp?
The high temp and low temp are configurable. The SDK example's readme.txt is
SDK boards/evkbimxrt1050/driver_examples/tempmon/Code:TEMPMON driver example. The chip initial temperature is 40.8 ℃. The chip temperature has reached high temperature that is 42.7 ℃. The chip throttling back core frequency to waiting a desired cool down temperature . The chip core frequency is 62500000 Hz. The chip temperature has reached low temperature that is 39.5 ℃. The chip will return to the normal process . The chip core frequency is 500000000 Hz.
#define DEMO_HIGHALARMTEMP 42U
#define DEMO_LOWALARMTEMP 40U
when i ran it, it just said "The chip initial temperature is 32.9" for the short duration that i bothered to wait ...
If you look at this document, https://www.nxp.com/docs/en/data-sheet/IMXRT1050CEC.pdf. for the max temp seems to be 95degC. So you could always set your alarm temp to something like 90 or 85? This doc has some more info as well https://www.nxp.com/docs/en/applicat...te/AN12170.pdf
estimated lifetime is not that bad
~10 years 0n 24/7 at 1.15 volts for commercial use - even if hot and reduced speed.
So looks like voltage is harder on it than temp near 200 F
So even cool with higher voltage to OC will reduce that
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