Teensy 4.0 (Without Pins)

This is very nice and fast little board. Just remember it is not 5v tolerant on any pins.I love the s/w support for the teensy product line.

In the past I've played with several variants of the Arduino family (Uno, Mega,nano editions etc). As a professional programmer I quickly found the Arduino IDE crippling, and so the Blue Pill (STM32F1/ARM based) became my go-to controller when used with an ST-Link v2 and the VisualGDB plugin for Visual Studio. The only thing I ever had trouble with was getting USB to work: there's a mistake on the Blue Pill PCB that gets you off to a bad start, and the sample libs from ST are not reliable, or at least are not well documented.I had heard about the Teensy but thought it was another Arduino variant, so didn't pay any attention. But then when watching some Flight Simulator 2020 videos I was struck by how often the Teensy came up as an easy way to get into DIY USB based joysticks and other Human Interface Devices. A couple of days later my first TeensyDuino sketch was working in the Arduino IDE, and then a day after that I had ditched the Arduino IDE and got it building and working with VisualGDB/VisualStudio again.The thing that seems to make the difference to create a reliable USB platform is that much of the work is apparantly being done by a tiny co-processor. This is also true of some models of Arduino, but the difference is that those Arduinos only see a UART, they can't actually use the USB interface itself.Lots of possibilities open up for the future, e.g. any project I can make that can be implemented using the USB functions of a mouse, keyboard, joystick or mass storage (which is pretty much everything!) - can all be done easily and doesn't even require special PC drivers on Windows 10, which has them built in.You can call me delighted... except for one teensy fly in the ointment (forcing me to deduct a star), being that there's no debug port! The Blue Pill costs way less but even _that_ has a dedicated debug header with a choice of SWD or JTAG debugging (with VisualGDB, Eclipse etc). With the Teensy I'm constantly aware that I'll be in trouble if it ever doesn't "just work". Online you'll find fanboys (obviously Arduino hobbyists, not professionals) who'll tell you that an LED and a printf is all you need for debugging: those guys have clearly never tried to debug a board that keeps bricking itself. LED and printf are indeed useful tools when the firmware is already almost working, but not when (say) some bug has disabled the PIOs, or changed the CPU clock, or got the firmware locked in the death grip of an endless NMI error interrupt loop.I'm aware of various projects in existence that try to get around the lack of a Teensy debug interface. In my brief research I didn't reckon any were quite there yet, but I'm keeping an eye on them.With that caveat I'm delighted to recommend the Teensy for your USB device projects.I almost forgot to mention the performance! The Teensy 4.x features an ARM Cortex M4 core running at 600MHZ (!), plus 1MB internal SRAM (!), and a flash that's way bigger than I'll ever need (~2MB). That certainly beats the pants off a Blue Pill, which itself utterly destroys the Arduino Uno. I also had a successful play with the TeensyLC (3.1) which has performance closer to Blue Pill, but still has that reliable USB coprocessor.One final note: this board is available "with pins" and "without pins". The "with pins" gives you about 60p worth of pin header soldered on for about £5. I prefer to save the £5 and do it myself! Perhaps there was some other benefit of "with pins" that I didn't recognize.

This device is almost cheaper than buying the micro standalone.But just the size of the device makes it a wonderful device to dev on for your project and fitting it is easy.

Good value

Two hours later it's a guitar pedal.

Not finished the project yet!

I bought this to upgrade a project of mine that was previously using a Teensy 3.2. Though it is a direct update to the 3.2, be warned that it's not necessarily a drop-in replacement and there are still a few rough edges in some of the libraries when it comes to Teensy 4.x support. For example, performing an FFT on an analog audio input using the Teensy Audio library requires a few hacks and even then doesn't work very well - I ended up replacing the Audio library with code of my own. There are differences in memory layouts too that you might need to be aware of. In addition, the Teensy 4 hasn't been well optimised for power consumption yet and as a result it can use noticeably more power than the Teensy 3.2; something to bear in mind for portable applications.All that being said, development has been otherwise straightforward (using CLion and the PlatformIO plugin). This really is a phenomenally powerful little processor, far more so than the (already pretty powerful) Teensy 3.2. Once I'd resolved some hurdles like those listed above, I've been blown away by what this thing is capable of. I'm now running complex floating point code at breakneck speed, no longer having to resort to fixed-point or integer maths and approximations to get the performance I'm after which has made my life much easier. I'm not sure there's anything else out there that comes close for pure performance in such a tiny package.