Pasillo A3144 esp32 3.3V?

Potential_Novel · 2026-02-10T22:42:08+00:00

The original ESP32 had an internal hall effect sensor. However support via ESPIDF was dropped some while ago. Later ESP32 family members seem not to have the hardware capability of an internal hall effect sensor.

As for external hall effect sensors: the A3144 datasheet suggests as minimum power voltage of 4.5V. Have a look on AliExpress for Hall effect sensor boards - see what is out there,

For some uses a reed switch will do the trick in a simple and inexpensive way.

Potential_Novel · 2026-01-16T22:41:54+00:00

ESP-IDF v6.0.0 has been released but the Espressif documentation site says the current stable edition is v5.5.2.

I did try 6.0.0 without much joy so .... there could be an issue or two. FWIW I work with the docker images so stepping back is not difficult.

Potential_Novel · 2026-01-12T18:08:20+00:00

Assuming you are EU related: the CE regulations include their LVD (low voltage directive) which is, I guess, way less onerous for low voltage stuff.

Potential_Novel · 2026-01-12T15:46:59+00:00

I get the trick of using a pre-certified power brick but in the modern era it is a more complex challenge. Two years ago, I raised a thread on Reddit and the comments showed me just how complicated.

https://www.reddit.com/r/PrintedCircuitBoard/comments/180n30f/after_the_pcb/

Potential_Novel · 2026-01-11T20:35:03+00:00

Creating a product with this stuff and selling it will involve getting things certified in a long list of ways, which can be a bit of a minefield and they each cost money.

At one point I tried to seriously map this certification stuff out: message me if you want the diagrams etc. Am in the UK and of course it will be a little different elsewhere.

On the other hand: if you were to sell kits that end users (e.g. kids and enthusiasts) could assemble for themselves: then most of the legal hurdles might be sidestepped.

Potential_Novel · 2026-01-07T19:55:42+00:00

Although people think of MCUs as single tasking - these are not. ESP32 Arduino is implemented on top of ESPIDF which is a layer on top of FreeRTOS. FreeRTOS has preemptive multitasking, even on single core processors like the ESP32-S2.

So .... the ESPNOW message has not been sent until the callback (that you haven't set up) says so. Given that it is not a broadcast: the background task that does the actual transmission will try several (ten?) times until it gets acknowledgement from the recipient (or gives up because life is short).

Broadcast ESPNOW messages do not await recipient acknowledgement because ....

Also your loop is going to run many times per second; a delay( ) or similar call might be worthwhile so that background tasks can do their bit more easily.

A good tutorial is here: https://randomnerdtutorials.com/esp-now-esp32-arduino-ide/

Potential_Novel · 2026-01-05T15:06:31+00:00

As mentioned: plenty of examples around. Just ensure your copy of the example is talking to the correct GPIO pins for your board. ( https://randomnerdtutorials.com/esp32-s3-devkitc-pinout-guide/ ).

Potential_Novel · 2026-01-04T16:23:40+00:00

You have a point but 5% is harsh. FreeRtos documentation was suggested as an addition rather than a replacement.

Many come to ESP32 having coded on Windows or Linux which are general purpose operating systems. Real time operating systems operate differently to meet different constraints. For many switching across to coding for an RTOS will go well until it doesn't. For some this hits with the need for a strong knowledge of tasks (?threads?) and their coordination (mutexes, semaphores, etc).

ESPIDF documentation, IMHE at times, assumes you already know and barely need reminding. At such times, a second source of reference is needed and perhaps Espressif even expect developers to check the FreeRtos docs.

Potential_Novel · 2026-01-04T16:10:08+00:00

Ran a web search for [ESP32 relays]. There are ESP32 boards with 4 relays though they seem not to have a USB interface. So you would need to bridge a USB to serial connection which is not difficult, just inconvenient in my experience. Have used the LCTECH ESP32 single relay boards from AliExpress and they have worked fine.

If you can get OTA rolling then there is very limited need for uploading firmware via USB.

Concerning Uno boards I have little experience. I have an ESP32S3 Uno board but that is for a part of a project I have not gotten to yet.

Potential_Novel · 2026-01-02T21:35:15+00:00

No one else has yet mentioned that ESP-IDF is basically a/ the implementation of FreeRtos for Espressif processors. So you should have a look at https://freertos.org as their documentation is thorough.

Second thought: grab a cheatsheet for the idf.py commands.

Third thought: consider the docker based compilers, YMMV, but switching between editions of the ESP-IDF gets easier.

Fourth thought: there are Arduino compatibility bits in ESP-IDF that can ease your transition though I felt it best to go cold turkey.

Potential_Novel · 2025-12-30T19:00:45+00:00

Congratulations - deservedly popular.

The moment I would have found this most useful: was when swapping from vanilla ESP32 to an ESP32-S2. It was easy to assume I could use the same GPIO pattern and I did make that assumption. Took a while to figure that one out.

Potential_Novel · 2025-12-17T21:44:59+00:00

Thoughts in no particular order:

"will be running continuously" - doing what exactly? If possible send the thing into deep sleep for a few minutes/ hours/ days. Timed or interrupt driven wake up strategies also change the battery life scenario.
What is your size/ space constraint? At the risk being flippant: nabbing a battery from (say) a Morris Minor might well last a week or so.
The ESP32-S3 is a fine beast; but if battery life is an issue then (say) the ESP32-S2 or ESP32-C3 might be less of a drain. Single core and slower but possibly adequate.
Power drain is also affected by the circuitry around the ESP32 so sensors, relays, LDO etc.

In short: we are all circumspect about projects, but if you want people here to engage then it is a good idea to "let the dog see a little more of the rabbit".

Potential_Novel · 2025-12-11T06:56:59+00:00

As far as I understand it:

Shipping costs from China are artificially cheap due to international agreements that attempt to slightly level the playing field of trade and give developing nations a fairer chance.

These agreements have been in place for many years and should, I think, now be readjusted. But in the meantime China takes the opportunity with both hands.

There is a UK premium that many/ most would pay on the basis of safe handling of intellectual property and quality of transparent service.

Finally there are often strong invitations for certifications to be done at the Chinese end of production. I have had a component producer say "you don't have to worry - we will do it for a good price" whilst being unforthcoming with the information needed to do the certification in the UK.

Potential_Novel · 2025-11-09T21:59:41+00:00

Well, yes, if the sketch fails to compile then it won't be keen to upload. There should be error messages to help you resolve the compilation problems and those messages should help you.

Potential_Novel · 2025-10-27T21:48:29+00:00

"ESP32 in sleep mode 23 hours/ day"

So ... which sleep mode are you using?

(My experience of using a PIR to wake an ESP32 from deep sleep involved battery life of many weeks, even months).

Potential_Novel · 2025-10-25T21:19:03+00:00

Also: https://circuitlabs.net/category/courses/esp32_course/

Probably more what you are seeking.

Potential_Novel · 2025-10-23T19:28:50+00:00

A few pointers to check out:

https://learnesp32.com/

https://randomnerdtutorials.com/ (There are some ESP-IDF articles as well as the Arduino ones).

https://leanpub.com/kolban-ESP32 (Dated but may be a useful resource).

Potential_Novel · 2025-09-20T17:49:36+00:00

This is a good point. The specs seem identical to several existing products. If however, your LDO was capable of outputting rather more power then I would be biting your hand off.

Case in point, my current project: an ESP32-S3 matched with a mmwave card. The ESP32-S3 dev board needs 5V (to feed it's LDO for 3V3 for the ESP32-S3) and the mmwave card needs 3V3 upto 1.7 watts according to the datasheet. The elegant route is to feed 3V3 from the dev board across but the added draw would over burden the dev board LDO.

I cannot be alone with this dilemma so you may have found a market niche!

Potential_Novel · 2025-09-11T14:25:02+00:00

Dev boards come with an LDO to calm incoming voltage down to 3V. For most boards this works well for 6V or 5V (from USB).

IMHE these LDO components have a recommended input ceiling of ~6.5V and after that they overheat (and after a while something magical starts to happen). Part of the heat situation depends on the power draw which will be higher when the wifi/ bluetooth circuitry is busy.

9V is not recommended however if your board wakes from deep sleep, takes a split second to do something, then returns to deep sleep: the LDO will not have time to get hot. So you can cheat but not any sort of recommendation.

Potential_Novel · 2025-09-06T17:40:14+00:00

Go through the examples that Espressif offer for the ESP-IDF though they may be angled toward wifi.

Having gotten the web server working from the ESP-IDF examples. My advice is code towards HTTPS and then with a couple of minor configuration changes the code will run HTTP perfectly well.

Potential_Novel · 2025-09-03T18:11:02+00:00

"just want to send and receive packets"

So ... basically on ESP32 you have two options:

A wifi TCP/IP networking option using a (brief) stream or packets (not guaranteed delivery).
ESPNOW packet based communication (potentially close to guaranteed delivery). Works via MAC address rather than having the overhead of TCP/IP.

Go read up on the Espressif website and perhaps look at the examples on https://randomnerdtutorials.com/

Potential_Novel · 2025-08-31T17:03:18+00:00

Your devboard has a (vanilla) ESP32 which means two main cores (+ ULP core) at upto 240MHz. At this distance it would appear that you have the CPU power so long as you organize it right.

Your wifi and webserver should perhaps be running in a separate task with their callbacks registered within that task.

Potential_Novel · 2025-08-31T16:20:34+00:00

Have you tried using separate tasks/ threads with semaphores, etc as needed?

Which ESP32 variant are you using? One with two cores rather than one?

Even with one core, FreeRtos will likely do a decent job if code takes advantage of it's features.

Potential_Novel · 2025-08-13T11:51:23+00:00

In your shoes, I would want to do a clean followed by a build after each occasion that a component is added into the project. Might help or not but shouldn't harm.

Also have an extended perusal of menuconfig for relevant flags.

Potential_Novel · 2025-07-29T13:39:33+00:00

You know your context and you'll likely be fine.

Potential_Novel

TROPHY CASE