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OK, I've confirmed that this is a hardware issue. I tried a different board that has a differential receiver (a different chip type) and no optical isolation. The software worked fine in this configuration. I'll continue tweaking the resistor values of the original design to see if I can get it...

Well, I got excited for a few minutes. I changed R11 to 220R and the rise time improved slightly, but no change in the symptoms. I'll look into the ADUM315 for future designs, but I've really got to figure this one out.

An isolated +5V for the DMX side and +3V for the MCU side. Here's the circuit.

I've successfully used the teensyDMX library in the past to send DMX data, and now I have an application that requires reading DMX data (and then relaying it through a wireless link). I'm having a persistent and baffling issue where the data is read correctly some/most of the time, but often...

I'm investigating the best approach and library to read animated GIFs from a micro-SD card and play them on a large LED pixel matrix. This will be done on a Teensy 4.0 that is performing other time-critical tasks, so any library calls need to reasonably non-blocking. I've just started evaluating...

Hi! I hope you don't mind if I ask a few more questions: 1. When testing the WebServerAP example, I see that server.handleClient() consumes about 2.5 seconds of CPU time (in two ~1.2 second chunks) each time that the simple web page is refreshed. I measured this with an elapsedMillis timer...

The WiFiWebServer that you referenced was written by the same guy as the ESP8266_AT_WebServer that I"m currently using. They seem to have similar capabilities, but there must be some critical difference that I'm not seeing yet. I'll play with it to see if it performs better. The LilyGo boards...

OK, I see what you're doing. A bit strange, but I'll come back to that in a minute. micros() is a free-running counter that isn't (I don't think) guaranteed to start at zero. It rolls over every 2^32 microseconds (4295 seconds). elapsedMicros is also a free-running counter. When defined inside...

Well, I'll go out on limb here: 1. elapsedMicros() and micros() are different, but in any case I don't see any calls to micros(). elapsedMillis() is probably a better choice. 2. In the lower code, you define time_elapsed and then use it in the calls to steppers.run() without initializing it...

Can anyone recommend a web server that will run on a Teensy 4.0 using an ESP-01 (ESP8266) wifi module? I want to implement some simple remote control panel functionality, and it doesn't need to be very fancy. It must work in areas with no existing wifi network or internet access, so the ESP-01...

upload_protocol = teensy-cli Many thanks, kind stranger! That worked like a charm! Uploaded a large-ish program 20 times, and it was blazing fast every time. So it looks like there may be an issue with the "graphical" uploader with both PIO and the Arduino IDE.

Hmm. Thanks, I'll try that

A little more info. After I rebooting my Mac, I no get the "An error occurred while uploading..." message. For the first ~8 uploads everything was very quick, but after that it started to bog down again. So basically the same as I reported before, just without the error message.

Thanks for the quick response, Paul! I haven't used the Arduino IDE in a long time, but I fired it up and tried it with the Blink example sketch. (It would take a while to translate my multi-file program back to that environment). Interesting results: Every time I hit the compile/upload button...

I've been using the Teensy 4.0 for several years as part of an LED controller for outdoor art installations (like this one). I've had some challenges for sure, but all were eventually overcome, often with help from this community (thanks!). For most of that time I've been using the VSCode +...

Yes, it seems like we're experiencing the same issue. I think I'll start a new thread about this, since the responses here are mostly about the SD library compatibility issue. I've been using PlatformIO for a few years, and the upload/serial monitor process has worked fine until a couple of...

I've been having similar issues with PlatformIO for a few months. I posted about this twice on the PlatformIO forum (most recent post, original post), but haven't been able to get a resolution. My current workaround (which now only works ~80% of the time) is to kill the Teensy Uploader before...

OK! Now I get: Starting WebServerAP on TEENSY 4.0 with ESP8266-AT & ESP8266_AT_WebServer Library ESP8266_AT_WebServer v1.6.0 [ESP_AT] Use ES8266-AT Command WiFi shield init done Attempting to start AP with SSID = EFD_NET and PW = 12345678 Access point started @ channel 2 AP IP Address =...

Thanks very much! I was just browsing through some of the other examples, and I noticed this: // TODO, WizFi360 can't use crashing localIP() So maybe I was on the right track. I'll try v1.6.0 and let you know how it goes.

This is exactly what I've been looking for! I'm using a Teensy 4.0 with the Ai-Thinker ESP-01 WIFi shield. I was able to install and compile the library and the WebServerAP example with no problems (using PlatformIO + VsCode). But...the program crashes during startup. With a little tracing, I...

Hi Joel, Thanks to you I'm been successfully using OctoWS2811 for a while, but I've run into a new problem described in this PJRC forum thread. Have you encountered the same issue? Thanks, Keith

As spolsky noted in this thread: By "this version" he's referring to the current version 1.4. To install this version of the library, I had been using the following hack: 1. Add the following line to the platformio.ini file: lib_deps = paulstoffregen/OctoWS2811 @ ^1.4 2. Add the following...

Hi, I just stumbled upon this thread while looking for something else. You and I are doing a lot of the same stuff, and I'd be happy to share my solutions to some of your questions. If you respond here then we can exchange contact info for follow-ups. -Keith

Hmm. I'll probably just wait until it's released for PIO. My project has >20 .cpp and .h files, and I dread the prospect of converting it to .ino files. Sounds like you think that Teensyduino 1.54 will solve the Time/TimeLib issue? Thanks for the super-fast response! FYI, I've been doing a...

After much initial difficulty, I've been (mostly*) successfully using SdFat 1.1.4 since last Fall. In starting a new project (using PlatformIO), I noticed that there are newer versions of SdFat available (up to 2.0.5). I tried the latest version but wasn't able to compile successfully. I'm...

Thanks! That looks like a possibility, but will probably require more adaptation (and time) than I can afford to invest right now. I was hoping for something more "turn-key".

Is it possible to load code (in the form of a hex file) into a T4 from an SD card and have the T4 behave as if the code were loaded through the USB interface? I'm using a custom PCB that includes a T4 and an SD card adapter. I'm providing the boards to remote collaborators (artists) with limited...

When I started working with LED lighting couple of years ago I read several articles and posts that explain that HSV was simpler and more intuitive than RGB in a number of situations. It's easy to produce color fades and gradients by manipulating a single variable (hue) while maintaining...

Yes, I use floating point for similar computations, but generally store "steady state" HSV values in 8.8 fixed-point format. Other than that I decided to focus more on numerical accuracy and readability than on code optimization. The resulting code is running so fast that I'll probably...

Last week I switched from FastLED to using OctoWS2811 for the LED serial interface (thanks to @spolsky and others), and it definitely solved my problems with interrupts being missed. Since I wasn't using any of the FastLED effects (I roll my own) and was only using the HSV to RGB color space...

OK, I downloaded the latest version from GitHub and figured out how to overwrite the old version in the PlatformIO Projects/<myproject>/.pio/libdeps/teensy40/OctoWS2811 folder. That fixed the compile errors. Now back to testing...

Thanks for the sample code! Before I saw that I tried the "rainbow" example and got several compiler errors, like: .pio/libdeps/teensy40/OctoWS2811/OctoWS2811.cpp: In member function 'void OctoWS2811::begin()': .pio/libdeps/teensy40/OctoWS2811/OctoWS2811.cpp:85:2: error: 'GPIOD_PCOR' was not...

A very timely post! I've been using FastLED on a Teensy 4.0 with parallel output (5 pins), and everything has been working fine...until I started using Serial1 to communicate with another Teensy. I was aware of the blocking issues with FastLED, but I had ASSumed that the T4 was so fast that it...

Thanks! I scanned the thread and will read more carefully later. Not sure if it only works with Visual Micro (and I'm not really sure what that is).

Ah, yes! I had meant to go looking for something like that (which I assumed must exist) but I never got around to it. Thanks for the reminder!

Thanks for all the suggestions. I think I have a handle on this now. The thing that threw me was that crashes prevent the output of serial monitor messages that were generated BEFORE the offending instruction. This makes sense assuming that serial output is interrupt-driven from a TX buffer. But...

Sorry, I manually (mis-)typed the code in the original snippet; the actual test code used "Test string" not "Test String". The program produced the following (correct) output: Level 0: string 0 Level 1: string 1 Level 2: string 2 Level 3: string 3 Level 4: string 4 The actual code (not the test...

I created a completely separate program to test strstr() when called several levels deep (see below) and of course, it works fine (ugh!). I included a 300-byte local variable buffer at each level to try to simulate a "large" stack. So it must be something about the particular code that I was...

After a recent update to PlatformIO, I started getting this compiler warning: I'm not using either of these libraries, but it looks like Time.h is being referenced by SDFat; am I reading that correctly? Does that mean SdFat will stop working if it isn't updated? I think I saw in another post...

I've been going crazy trying to debug a problem with using some of the standard string functions, particularly strstr() and strchr(). When I use these under certain conditions (see below), my program always crashes, as indicated by lack of any output on the serial monitor and the need to press...

OK, I ended up getting a super cheap (<$2) Micro SD adapter and a super cheap (16GB, $6) SD card and hand wired the adapter to the T4 SPI pins (photo). Got it up and running today using the SdFat library. It's only running with a 4MHz SCLK. I haven't tried to jack up the speed, and probably...

I don't have an answer to your question, but I'm curious how you like using the TLC5940. I thought about using it, but then I found the TLC5947 which seemed to be a better fit for me. I built a custom PCB based on that, but during testing found that the TLC5947 (and I think the TLC5940 also)...

Thanks for the suggestion, but I'm using the T4.0 mounted to a custom PCB without a lot of spare real estate. Even for the boards I haven't assembled yet, there wouldn't be room for this breakout board. I think I'll just use wires to connect a small SD adapter. Fortunately all of the necessary...

Can you recommend the easiest way to add a micro SD adapter to a T4? It looks like I could use the small PJRC adapter with discrete wires, and it wasn't immediately obvious that the larger adapter is in any way pin-compatible (using the headers) with the T4. For future projects I'll switch to...

I just found this thread, unfortunately after I've finished developing my hardware around the T4 based on some incorrect assumptions about this line in the tech specs: 2048K Flash (64K reserved for recovery & EEPROM emulation) Since I expected to have 5-10KB of configuration data, I wasn't...

...and there it was! (after I pressed Cmd+Shift+Dot to expose hidden folders/files) Thanks!!

I'm using VS Code/PlatformIO on MacOS 10.15.5 to develop code for a Teensy 4.0. I'd like to be able to generate a hex-format object file and send it to a collaborator so that he can download it to a T4 without having to replicate my development environment. It appears that a "firmware.hex" file...

Thanks very much, @defragster. I thought I had considered everything you mentioned, but I didn't check carefully enough. I have a switch on the Power On/Off pin, and due to a discrepancy between the switch's schematic symbol and the footprint, the pin was tied to ground. Once I removed the...

I've used several T4.0 boards over the past few months with no issues, but the new one I just received is behaving mysteriously. On power-up, the LED flashes three times and then stops (about 4 seconds). The board is not recognized by the Teensy loader (with one exception: see below). I found...

I'm using these with a Teensy 4 and 24V LEDs.