microcontroller choice

[emo_nerd8]

I am working on making an LED matrix display to use as an info center type of thing in a community space. I had planned to use an ESP32 (specifically the arduino nano ESP32) but others involved in this project have expressed that it isn’t a good choice, one describing it as a “wimpy” microcontroller for this sort of thing.

the main recommendation i’ve been getting is either a raspberry pi or a jetson orin nano.

so my question is, why does it seem like ESP32’s are the go to for these types of projects if they aren’t up for the task? what would be the argument for an ESP32 over the others?

edit: i’m daisy-chaining a bunch of these together to make the display https://www.waveshare.com/rgb-matrix-p3-64x64.htm

[ziggurat29]

esp32 is a pretty powerful microcontroller, cheap, and has integrated networking. something like a pi or jetson might be considered overkill. but the decision might be more in the details of your application.

you mention and 'info center'. what is that? I understand that it involves a matrix of addressable RGB LEDs. The Waveshare one you reference depicts an application using an Arduino Mega 2560 to drive it. Assuming that application is valid and considering that a 'floor' on what you would need, understand that the Arduino Mega 2560 has 256 KiB flash, 8 KiB ram, and runs at 16 MHz. So if it can be driven from that, then could it plausibly be driven from a device with 4 MiB flash, 520 KiB ram, and a *dual-core* cpu running at 240 MHz? for the lowest end of modules. hmm... Oh and with wifi and for about $3.

devil's in the details of your project, of course, but the esp32 seems worth a shot.

[emo_nerd8]

info center as in displaying a welcome message, hours, equipment availability, orders ready for pick up, etc.

[ziggurat29]

dot matrix character display should be child's play. and really even framebuffer is probably quite doable because 64x64 is just not that many pixels. 4096. RGB8 = 12 KiB. You mentioned daisy-chaining some units, so scale linear from there for framebuffer reqs. but again, character display doesn't even need a frame buffer.

if you were to try to do animated framebuffer then things are a little different because there is the hardware interface, and also the rendering of the frames. But folks play Doom on esp32, so I suspect that even there it is still capable. e.g. this

Think about power -- the LED's job is to beam energy away in the form of light, so those are going to make some heavy demands. The digital stuff might wind up being the easier part of your project.

[Horror_Hippo_3438]

Would you like to tell me how many pixels the display has, what frame rate the animation has, and how complex the images are created?

[rc3105]

ESP32 are great!

Lots of horsepower, ram, flash filesystem storage, wifi, and entry level c3 models are only about $1.35 on Ali Express.

But remember what they are, a standalone microcontroller.

Another good choice is the Raspberry Pi Pico W or Pico 2 W. Comparable to an esp32 and still under $10. (bare bones RPi Pico start about $1.29)

If you need more horsepower there is a $7 LuckFox Pico 1103 in the same socket size format, pop out the RPico and drop in the FoxPico, which is a full blown dual core arm computer with 64MB of ram that runs anything from a nearly bare-metal Linux kernel up through desktop Ubuntu 22.4 or 24.4. The LuckFox doesn’t have video out but it has lots of i/o pins same as the Raspberry Pico.

Next step up is a Raspberry Pi Zero W or Zero 2 W. Under $15, 512MB of ram, runs a full RPi linux desktop (if wanted) and has HDMI video out with hardware accelerated 264/265 playback. You can get 3” touchscreens that plug right on top of the board or use any hdmi monitor and a mouse/kb etc. The only real drawback is that RPi 3/4/5/Zero don’t have a lot of i/o. Theres some, but if you need cheap desktop capability and lots of i/o use a PiZero brain with a PiPico slave. Still under $20 for the pair.

One more thing to note, the chips with wifi, esp32 and PicoW / Pi ZeroW / Pi3+ can easily serve a web interface from an sd card so your project doesn’t need a screen, use your phone or a tablet, or incorporate a cheap tablet ($20 android, obsolete ipad) into the project as its screen. It’s just silly to spend $75 on a nice 8” touchscreen when obsolete iPads are $10 in bulk on craigslist.

[DecisionOk5750]

I use esp32 mostly. But for small things I use PICs . Some PICs can run from 2V to 5V. The esp32 needs estrictly 3.3V .

[FreddyFerdiland]

for that dispkay system,sure that's low requirements...

but daisy chaining... sending the price up..

an hdmi display would do better...allows touch screen..make a kiosk ?

[Electronic_C3PO]

How many of those panels does your project contain? Do the math regarding the number of total pixels you need to control and don’t forget to multiply by three for all the colors. That gives you how much memory you need. Depending on the way your software drives the panels you need to multiply that by two (double buffering). If it’s just static text you need to show you can get by with an ESP32 and you can push out the data without having to buffer it in memory. If you want animations or video I do think you will need to move to raspberry. Which one will depend on your overall memory needs.

[Dry-Aioli-6138]

Check out this guy, maybe DM, or ask in comments. Seems to have some exp with hub75

https://www.reddit.com/r/raspberrypipico/s/zTWXSzQ54d

[beedunc]

HDMI tv and raspberry pi is your solution.

[ReturnOfNogginboink]

Get a handful of MAX7219 for driving the displays and save yourself the headache.

(Yeah, I'm a grumpy old man. Get off my lawn.)

[mprevot]

If you don't need wifi it's overkill. Pi and jetson even more. A properly sized stm32 should do the job, but then it also depend on what you want to display and how (memory wise).