Teensy 4.1 Review

jdredd

Active member
My Teensy 4.1 kit from Amazon showed up today.

I didn't even fire it up before soldering it up.

Added both 8mb chips for 16mb total.

Soldered up the RJ45 setup.

Soldered on the pins.

And wham! up and running after installing the required software.

Wow, this thing is impressive!

I've been working on A little project over past few weeks. Started with an Arduino UNO. Hit the limits of it pretty early on.
Lack of space for code. Lack of ram.

I had two Raspberry Pi Pico's laying around I bought on launch day but never really messed with.

Using this currently, as it gave me much more space for code and tons more ram.

I ordered the Teensy 4.1 as a back up plan incase the Pi Pico didn't work out.
Sadly, it has worked out and I am pretty far along.

BUT just may halt progress and move to the Teensy 4.1.

Why?

1) RAM is a huge thing. I want to buffer data incoming from A vehicle PCM and write to SD card after some time. Which means I want A good chunk of ram to do so.
So can do less writes in bigger chunks.

2) Speed. This CPU is A blast. I can be doing up to 30+ different calculations 4-5 times a second, so 120-150 calculations per second. Simple math, shift lefts/right, ect to convert incoming data into actual end result values.
More speed the better to fly through these. And display some of them on A simple 20x4 LCD screen to end user.

3) SD Card onboard. Just one less thing to worry about wiring up. I wish the SD slot would lock the card better and push on it to spring eject it out like SD shield I have, but I'll survive.

4) Ethernet? Hell yah. I really hate WIFI and Bluetooth. Always A pain it seems. Now I can make A simple web interface to plug laptop in or phone with ethernet adapter.
Bypass the 20x4 LCD screen for the quicker web interface if desired.

5) Pins pins pins! Lots of serial ports. Multiple SPI and I2C ports. This thing makes life much easier.


It's not much bigger than the Pi Pico but offers so much more.
The Pi Pico has dual core CPU which is nice, as I can off load serial processing on the 2nd core but the speed here I think will make up for it and be able to blast through it just fine in single core mode.

I've tested SD card access, ethernet webserver, extended ram, serial interfacing to the Sparkfun OBD2 board and works like A charm.

I have hard choice now to stop and migrate to the Teensy 4.1 which really now I think about it.... not A hard choice. Just do it and get it over with and don't look back :)

Maybe only "downside" is voltage input. Pi Pico allows 12v input. Which is what I am using. So will need A way to get it down to 5v.

Otherwise, day one playing around, all I gotta say is, Great job! This thing is awesome!
 
I've used the Pololu voltage regulators in the past (note, I haven't used these specific regulators, as I tend to prefer the step-up/step-down regulators that can handle 3-11v, and only need 500mA to 1A):

 
I've used the Pololu voltage regulators in the past (note, I haven't used these specific regulators, as I tend to prefer the step-up/step-down regulators that can handle 3-11v, and only need 500mA to 1A):


Thanks i'll check these out. I had some I threw away of no name brands. They were to flakey.
 
Welcome home.

I too had issues with Arduino--ram was the killer. I moved to Teensy several years and and never looked back. Other things I find useful

1. ability to set the pwm frequency
2. very fast ILI9341 drivers
3. built in RTC
4. 3v3 which seems more compatible with sensors and such (no level shifters for SD cards)
5. more EEPROM space
6. way better forum--people over hear help and do it with respect
7. the list goes on and on
 
Welcome home.

I too had issues with Arduino--ram was the killer. I moved to Teensy several years and and never looked back. Other things I find useful

1. ability to set the pwm frequency
2. very fast ILI9341 drivers
3. built in RTC
4. 3v3 which seems more compatible with sensors and such (no level shifters for SD cards)
5. more EEPROM space
6. way better forum--people over hear help and do it with respect
7. the list goes on and on

Well I ended up switching my project over... Took me under 20 minutes to rip out the Pi Pico and put in the teensy 4.1 and to update my code.
Only thing not done is the SD card support, just commented that out for now. But everything else works!

What is nice, is less things. I had an RTC board I just wired up today.. now, don't need that.
Don't need the SD card board anymore either.

The biggest plus.. is I can leave the Serial Monitor open in Arduino IDE when I upload the code!
Pi Pico I had to close the monitor down every time. Such A pain, because you can't get it up fast enough to see the Serial output. Miss stuff on boot up code.

I'll miss the 2nd core option... maybe... but the speed of this I think will out perform it in the long run.

I do wish it had 5v support, as the sensors I'll be wanting to tie into are 5v, but I'd have to do the same with Pi Pico once I got to that point.

So far so good and very happy with the results.

I think the only "big" thing I notice is time to boot up.

When I plug in power to getting things going during the startup, seems noticeably slower.

Example, plug in power or push the button and it takes 5 seconds for it to go.
The Pi Pico was up and going in under 1 second.
 
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What is nice, is less things. I had an RTC board I just wired up today.. now, don't need that.
Don't need the SD card board anymore either.
Welcome to the fold, I am sure you won't forget it.
Things to bear in mind though, you may find that the RTC back up battery does not last very long and there may be drift over time (sorry about the pun).
 
As a solution to the RTC problem I found this.

It's an RTC with ultra low power with a current drain of 45nA and an accuracy of +/-1 ppm.

And the good thing is they will send you some FREE samples. I managed to get a demo board and a number of ICs.
Demo Board
 
As a solution to the RTC problem I found this.

It's an RTC with ultra low power with a current drain of 45nA and an accuracy of +/-1 ppm.

And the good thing is they will send you some FREE samples. I managed to get a demo board and a number of ICs.
Demo Board

Thanks. I don't have the RTC/Battery anything hooked up at the time.
I don't 100% need it but would be nice so when logs are made I can have A true time stamp.
 
Also the slowdown issue I had on startup of my program. All my fault :)
Debug stuff from the Pi Pico stuff to deal with serial monitor. Removed it and blamo. Fast.
Missed it when I blew through my conversion this afternoon. Ooops.

The ethernet I am digging.

Added the simple web server to my program. Able to configure DHCP or not.. and if not, define your IP.
And have my Android phone with USB adapter to RJ45 connected and talking to it.

Crazy how nice this thing is!
 
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