defragster

Is this 'pending' the same state cleared when the interrupt service is marked complete on _isr exit? That is if SysTick 'in progress' when the next SysTick triggers it won't interrupt immediately on exit?

ARM implemented a nice "tail chaining" optimization in the hardware, because it is a common case where 1 or more other interrupts are already pending (at the same or lower priority) when your interrupt finishes. Rather than restoring the...

inclusion of u8x8.setI2CAddress(0x7a);//0x3d x 2 did the trick. Many thanks all!

What I believe he was suggesting, is to try out using the Adafruit SSD1306 driver, which even if that is not the driver you wish to use it will help isolate the issues. Looks like the display is setup to be 3.3v compatible. Might help if you...

In case anyone's wondering about 1.60-beta1, I lost a couple days because an update broke my Yubikey-based code signing for Windows. Things used to be so much simpler when it was just files and I could build inside a virtual machine. Just now...

That isn't the driver seen in use - and that code doesn't show the i2c address (which is always confusing as 0x3c or 0x3d) Found a sketch used here with a PJRC i2c demo board that starts like this: #include <Wire.h> #include <Adafruit_GFX.h>...

@jmarsh p#37 notes details on the cache - ideally the 32KB cache is designed to most effectively afford efficient access with minimal overreading and only writing back changed blocks. Profiling and use case might show the cache being less than...

First quick look, I don't understand why this? Normally with DMA usage you would have the ADC or ADC_ETC trigger DMA only, and then DMA generates the interrupt when transfer is complete.

I'm not a fan of Discord or other chat-style systems.

Searching for arm_dot_prod_q7 shows it does indeed exist. In CMSIS the floating-point and fixed-point types are indicated by f16, f32, f64, q31, q15, q7 in the function name... But check the documentation, you might not be wanting fixed-point...

Best not to do prints from an ISR. That will invoke USB activity that is at a raised priority - and can cause collisions with other output elsewhere. Perhaps use a pin for Toggle on entry/exit. If the _isr() were set at a higher priority then no...

PJRC Audio library makes extensive use of some ARM DSP for processing twin 16bit data sets in 32bit words. Not sure of the nature of those operations - but as @AndyA notes - it is worth looking into.

@jmarsh - was it a post you made showing at least one build/source edit that dropped ITCM code by some measurable amount? Having to do with C++ reservation or other [fault or output stubs?]? It would be best to work on building to reduce the...

This thread appears to have a life of its own! Here is my 2 cents worth... Probably worth about that much: If your arrays are initialized as part of the build process and are larger than can fit into RAM1 and as such you need to put them into...

A one line CORES edit can make the unused RAM1/ITCM 'padding' available as "READWRITE". In the example above that area is over 30 KB - but can be less than 1KB depending on the build. This risks self(virus)-modifying code or the dangers of...

It was always claimed 'Read Only' but worked when last checked with this code last edit Feb 2023. ... // LAST PRINT printf( "End of Free ITCM = %u [%X] \n", ptrFreeITCM + sizeofFreeITCM, ptrFreeITCM + sizeofFreeITCM); // This now causes...

@Lesept ... @Dogbone06 has put forth a design with 32 MB of SDRAM with PJRC Bootloader. There is a thread or two dedicated to that, as well as some other with display and camera usage. It is based on Teensy MicroMod since it uses a 16 MB Flash...

Not sure the value in getting the systick turned off - it will trigger 1K interrupts per second - but they couldn't be much shorter. Reading the ARM_DWT_CYCCNT takes about 3 cycles and ++ of the count about the same? The ARM_DWT_CYCCNT count is...

Until a device is activated the Millis_Tick is the only thing running on interrupt. Losing Button update is known - but USB is disabled with a 'NO USB' build. No active interrupts can be seen with : asm(" wfi"); Even the Millis_Tick "ISR"...

Or you could do, what I do way too often, is to leave the useful information to the imagination of the would-be readers 😉 Often when I do the little bit I do, I look at some of the pages up on github, like...

@all - I have updated the pinouts in the TeensyRA8876-8080 library...

You might take a look at <this> post discussing how I previously (successfully) used the 75HC595 to drive a large number of LEDs as indicators on an earlier version of my TeensyMIDIPolySynth. Using this shift register only consumes a couple of...

Quick behind-the-screens update... the plugin generated its first automatic report. Indeed it's spammers (probably from Bangladesh) blatantly creating many accounts. The plugin seems to really improve the forum's logging and display of the IP...

Ok, it's installed and running with default settings. And wow, it has a lot of settings! Looks like it's going to use free tier IP geolocation services. If we get good results but hit limits, will look into paid tiers.

I purchased this plugin. Will install soon. Hopefully it'll help cut down on the spammer registrations.

Yes, generally the power and problem of edits to CORES files is manually maintaining any edits to any IDE install or update. Some changes may lend themselves to a means of isolating or extracting them to more maintainable edits, though some...

yes (re p#2) - check - UART spec puts both ends of Rx and Tx at high Voltage on Stop - so the 1.8V GPS will need to tolerate 3.3V from Teensy. Thread delete is rare - just mark with link to this thread as Active - it may get closed ...

You could use "Serial3.flush()" rather than "delayMicroseconds(1150)". The flush() call will block until all the data has been transmitted. Information on the serial hardware is listed at td_uart.html

You have two options to create stuff on the stack: 1) You can use a variable sized array. It may be simplest to move the main of the code into a function, and pass in the length as an argument: void inner (size_t n) { uint32_t buffer[n]...

slow clap for the stupidest spammer on the forum

Please do report the spammer profiles when you see them. I do use the IP numbers from those reports, so the reports really do have value beyond just cleaning up junk.

And on T_3.6 there is no factory program after 15s holding of program button only empty flash and for programming you need to press the program button again (IIRC)

Generally, not had problems since Win 11. Search forum for tycommander - that is most often used SerMon program here and generaly provides better connectivity and feedback. Is this really a T_3.6? or is it a T_4.x being misidentified? On a...

Hey folks, I'm happy to report I was able to create a custom teensy with sdram using this thread as a reference 😁 I was already in the throws of designing a custom teensy board that had usb host, usb device, and microsd all on a single edge...

In some fashion might add "... Do not remove power from the Teensy during this process with the RED LED on ..." also here https://www.pjrc.com/store/teensy41.html and here https://www.pjrc.com/store/teensy40.html - some may wrongly assume the...

That 'Board' manager install includes all the essential software to build for Teensy. Only added devices or software features would require additional libraries. regarding " thread on how to learn to learn Tensy 3.2." ...

A new repos, or rather an old repo with new content is posted to github. https://github.com/drmcnelson/Arduino_Timing There you will find some measurements for timing for digital write, read, toggle, SPI transfers, interrupt latency and so...

This is 9 years old - and it got to a point where there was a working example or two of buttons working in some fashion https://github.com/Defragster/XPT2046_Touch_Examples/tree/master/onoffbuttonMark3 and this are in the same repository...

Another quick Bluetooth update: I have been tearing apart some of this code and probably screwing up everything ;) In particular, I have now broken up bluetooth.cpp into two files. More specifically the BluetoothController object used to have...

Just to add a bit more info, long ago we had much simpler defines. But in practice that leads to inefficient code. When each define is just an address, the compiler doesn't "know" they're all the same peripheral. In typical usage where you...

Could put things here on this thread? Here is a screen shot of this : https://github.com/KurtE/TeensyDocuments/blob/master/Teensy4%20Pins.pdf

The online-only info already has this edit: Yes, I'd be happy to add a link to a forum thread where more detailed info is given. The Teensy 4.1 page has such a link. Is there a thread or message with Kurt's spreadsheet or something similar...

There is a LOT of information, that could be added here. The question has always been how much is too much for the majority of people? For myself, I want all of the data, so I created my own: Here is one page of my excel document, that I keep...

And FWIW, in addition KurtE's wonderful document, I have a google spreadsheet that I try to keep up to date. https://docs.google.com/spreadsheets/d/1LSi0c17iqtvpKuNSYksMG306_FpWdJcniSRR6aGNNYQ/edit?usp=sharing The first sheet compares the pin...

With the Teensy.exe loader open open the Help / Verbose window. Perhaps unplug the Teensy Clear the Window text Then repeat plugging it in and Button Press and watch for the posted notes Trying a 'known good' Quality cable would be the first...

First check would be confirming a good quality data cable. Power only of course isn't capable, but the T_4.x USB runs faster and is more demanding of a quality cable. Does the computer make a USB Device recognition on plugging it in? And again...

If there is room for simple edits (future card?) the online card could be edited as a reference? Links there to 'added info thread/post'

The printed cards won't change anytime soon. Short version of the story... the printing shop raised prices pretty substantially, but allowed us to place 1 last order at the original price. We ordered a large quantity, enough to last well into...

I see my licenses are noted: 11:38 PM 5/26/2021 and before that 4:52 PM 3/16/2017 Yes, just to limit access to Updates - though trying the access to the above build settings is when I saw it and the github notes didn't seem to work the same with...

Looking at github TSET it linked to https://forum.pjrc.com/index.php?threads/use-sublime-text-as-an-arduino-ide-replacement.38391/page-4#post-193136 That has some notes on BUILD set'ting My Sublime saying I need to UPGRADE ... $80 after 3 years...