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Unveiling secrets of the ESP32: creating an open-source MAC layer

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Re: Unveiling secrets of the ESP32: creating an open-source MAC layer

#31

Post by asylteltine »

finnjohnsen2 wrote: post #13

I wasnt aware of this wifi blob. This feeds a tiny paranoia I have at the back of my head when dealing with esp32/espressif. I have dozens of esp32s around and I love them, but Espressif is 100% Chinese. Im uncomfortable with what I read that every company of significant size in China automatically requires CCP party members to be involved in the company at a high level. So Im very happy to hear people such as these…

I restrict my esps to local network only absolutely no internet access for them. No trust for Chinese products from Chinese companies

Re: Unveiling secrets of the ESP32: creating an open-source MAC layer

#32

Post by raajg »

zlg_codes wrote: post #30
PeterisP wrote: post #28

Earlier quoted context omitted.

Alternatively, you can go high-level immediately - instead of accepting a UDP packet to set the color, run a webserver on it with functionality to change the RGB LED color that you can access from any browser. Modern microcontrollers have enough resources to just spend them like that.

Are we talking lightweight servers like minihttp and shizaru, mid-level lighttpd , or big-ass Apache and nginx?

Pretty barebones but working web servers are possible. Example: https://randomnerdtutorials.com/esp32-web-server-arduino-ide...

Re: Unveiling secrets of the ESP32: creating an open-source MAC layer

#33

Post by raajg »

For someone unexperienced with ESP32 but wanting to dip your toes, I'd highly recommend M5Stack - https://m5stack.com/ . No affiliation whatsoever, but I started playing with some basic boards last year for the first time and the the tiny devices they build have so many different sensors, transmitters, etc that you can start with a lot of early experiments just using a single device and a USB-C cable.

Re: Unveiling secrets of the ESP32: creating an open-source MAC layer

#34

Post by PeterisP »

zlg_codes wrote: post #30
PeterisP wrote: post #28

Earlier quoted context omitted.

Alternatively, you can go high-level immediately - instead of accepting a UDP packet to set the color, run a webserver on it with functionality to change the RGB LED color that you can access from any browser. Modern microcontrollers have enough resources to just spend them like that.

Are we talking lightweight servers like minihttp and shizaru, mid-level lighttpd , or big-ass Apache and nginx?

We're talking lighter than minihttp and shizaru - instead of a separate process on an OS, you'd use library that allows your firmware to respond to http requests, but that still allows you to run all the relatively complex UI/UX code on the user's computer or phone, with the microcontroller only handling the physical functionality; and reduces the need to have and manage more physical buttons/lights/screens/etc on the device itself; but you can do that without writing a separate app to generate some custom command&control messages - as in the grandparent post example of encoding RGB light control in an UDP packet, it would probably need three times the amount of code both on sending and receiving side compared to a http-based rgb control, which can probably be done in ten or so lines of your own code.

Re: Unveiling secrets of the ESP32: creating an open-source MAC layer

#35

Post by ibizaman »

PeterisP wrote: post #28
jof wrote: post #26

Earlier quoted context omitted.

Make an LED blink. Then, connect an RGB LED and experiment with PWM signal generation. Then, experiment with network programming, accepting a UDP packet to the ESP32 that sets the color of the RGB LED.

Alternatively, you can go high-level immediately - instead of accepting a UDP packet to set the color, run a webserver on it with functionality to change the RGB LED color that you can access from any browser. Modern microcontrollers have enough resources to just spend them like that.

Just install ESPHome on it :)

Re: Unveiling secrets of the ESP32: creating an open-source MAC layer

#36

Post by rgovostes »

droptablemain wrote: post #25

I picked up an ESP32 devboard recently. I've always been intrigued by embedded but don't have a background in it at all. I have no idea what my first project should be. Any ideas?

The barrier to entry has never been lower. Last night I prototyped some code in Python on my Mac to talk to a Bluetooth peripheral, and then had ChatGPT translate it to Arduino C++ code for a $5 ESP32, and it mostly worked on the first go.

You can even run Python on microcontrollers these days. See Adafruit's https://circuitpython.org for which they publish modules for many (almost all?) of the sensors they sell. The modern microcontroller frameworks hide much of the complexity of Wi-Fi, Bluetooth, filesystems, etc. so you can do complicated things with minimal effort. You can really cobble something together in an afternoon.

The "hello world" of microcontrollers is making an LED blink. Then figuring out how to print a message out over serial (print debugging is invaluable). Then maybe figure out how to make a Wi-Fi connection and an HTTP request. Then go on a shopping spree on Adafruit or SparkFun for $9 sensors that spark your imagination and figure out how to talk to them; Adafruit publishes zillions of tutorials you can copy from: https://learn.adafruit.com

Re: Unveiling secrets of the ESP32: creating an open-source MAC layer

#37

Post by adolph »

jareklupinski wrote: post #21
Max-q wrote: post #3

The article claims that the ESP32 costs $5. The reality is around half of that for the MCU, and around $3 for pre certified modules including crystal, PCB antenna or UF-L connector. So it's really affordable. Espressif has also launched a new ESP32C3 based on RISC-V, with modules priced at around $2.

that second core is worth its weight in gold cant wait until they can make a dual-core risc-v but p.happy on the -s3

Dual core RISC-V? Presenting ESP32-C6:

It consists of a high-performance (HP) 32-bit RISC-V processor, which can be clocked up to 160 MHz, and a low-power (LP) 32-bit RISC-V processor, which can be clocked up to 20 MHz. It has a 320KB ROM, a 512KB SRAM, and works with external flash. It comes with 30 (QFN40) or 22 (QFN32) programmable GPIOs, with support for SPI, UART, I2C, I2S, RMT, TWAI, PWM, SDIO, Motor Control PWM. It also packs a 12-bit ADC and a temperature sensor.

https://www.espressif.com/en/products/socs/esp32-c6

[The High Performance] CPU . . . has 4-stage, in-order, scalar pipeline optimized for area, power and performance. CPU core complex has a debug module (DM), interrupt-controller (INTC), core local interrupts (CLINT) and system bus (SYS BUS) interfaces for memory and peripheral access.

The ESP32-C6 Low-Power CPU (LP CPU) . . . features ultra-low power consumption and has a 2 stage, in-order, and scalar pipeline. [It has same features but lacks core local interrupts (CLINT)].

https://www.espressif.com/sites/default/files/documentation/...

Re: Unveiling secrets of the ESP32: creating an open-source MAC layer

#39

Post by BertoldVdb »

mschuster91 wrote: post #29
zamadatix wrote: post #15

Earlier quoted context omitted.

If the product doesn't list some form of dB loss (at at least 1 frequency) I assume it's more or less just a standard box. Sometimes that'll be right, sometimes it won't. Some of it comes down to how you use the box as well. If you're feeding un-isolated power in via a big hole in the back then it doesn't really matter how perfect the front is at blocking signals. I'm surprised their paint can only gave them a 10 dB…

At least for microwave ovens, with domestic models reaching 1 kW and commercial (e.g. in food) 2 kW, the shielding on these needs to be pretty darn good to make sure that someone standing right next to it doesn't get their body fried. The maximum allowed leakage power density is 5-10 mW/cm² [1], according to a 2004 study even then most ovens barely get up to 1% of the legally allowed emissions limits [2, page 7]. Out…

Don't underestimate the dynamic range of a modern wifi transceiver. It is transmitting at ~20dBm and will receive down to at least -80dBm. You need to achieve >100dB attenuation, well beyond what a microwave oven provides.

Even a solid metal box with a few small holes will struggle.

Re: Unveiling secrets of the ESP32: creating an open-source MAC layer

#40

Post by Sprite_tm »

madushan1000 wrote: post #22

I think bl602 shares the wifi rf/mac layer with esp32. There is a monitor mode implementation here https://github.com/stschake/bl60x-wifimon/

No, it doesn't. I know with 100% certainty ESP WiFi hardware is developed in-house and not shared. I think BL602 uses CEVA IP, not sure about that, but it certainly is not shared with ESP chips.
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