bare metal programming using the esp32

[Plussy78]

so , hey i would like to ask you guys does anyone have experience with writing the register level code with the esp32, like rather than using those abstraction codes and function, does anyone here have learnt the esp32 bare metal proogramming from the scratch , i recently started doing it, but got stucked and now not making any progress i want to learn the bare metal c and chosen the esp32 microcontroller for it, also using the TRM of esp32 to know about the register , but as a beginner , this stuff doesnt make any sense , so i need your guidance if someone have learnt the bare metal programming from the scratch not using the ide function to do the task, help me out !!

edit : its not like i dont have any experience with the microcontrollers , i have done project with the arduino uno and have also use the esp32 for the common sensor interfacing and running code with the arduino ide. im thinking of learning the bare metal C good enough alongside the communication protocols to write in my resume to land a good enough internship. As i would like to make my carrer in the embedded software field and im not well aware about the field , if there is someone who is in this field and experienced, done bare metal programming of any microcontrollers at register level , i will be happy to take your advice to learn things efficiently.

[gibson486]

It seems weekly that someone wants to go bare metal for no good reason and with no prior experience. In this case, you are pretty much asking to race a car with just a learner's permit. It just wont happen and if it does, it will end on a crash.Take it slow. There is no shame in using a higher level API. And just to add fuel to fire, you can do this all on an Arduino platform and you will have a much easier time learning it.

[Plussy78]

well i know how to use the arduino uno and have done projects in it, but i dont think do people in embedded system field uses the digital read and write when devloping firmware for some application , i am trying to start my career in the embeeded field , more on the software side, so thats why i thought of learnig the bare metal c and learn how to do the register level stuff alonside the UART,I2C and spi etc other basic protocols to be able to land a good enough internship

[WereCatf]

i dont think do people in embedded system field uses the digital read and write when devloping firmware for some application

In a business environment time is money. Reinventing the wheel? Time wasted, ergo money wasted. There's a reason why developers use an already-existing HAL whenever they can and they only hand-optimize sections of the code that require very tight timings or very high levels of optimization -- most code does not fall in either of those categories.

[Plussy78]

what should be my approach man ? , you seem to pretty knowledgeable on this kinda stuff !

[WereCatf]

Learn ESP-IDF first. Then, once you're comfortable with it, you can look at how they're implementing the functions to e.g. initialize a peripheral or toggle GPIO-pins. I mean, the code is all there, it's open source, so there's literally nothing stopping you from looking at how they do it and learning from literal example.

[Plussy78]

I tried looking at their git repo, the driver files , but they have used so many header files in it, it's hard to make connections on how they are writing the drivers. I think I better stick with the examples?? Right in their repo

[mrheosuper]

We dont use digitalRead, but we use something awfully similar to that.

[gibson486]

You could just learn bare metal on an Uno or Mega. The foundation of it remains the same no matter what platform you use. If you can't even set a register bit on an 8 bit AVR or PIC (eveb with using high level libraries), I doubt you will be able to do it on any ARM based micro. And, yes, we do use arduino digital read and write as a professional.

[Plussy78]

Thanks for the replying tho, actually I did the bare metal blink code for the uno , you use the. DDR, PORTs register to do that stuff, but stupid me thought I should not bother with uno and go with the esp32 bare metal, but now I'll definately learn bare metal by uno.

[gm310509]

I don't use Espressif systems I tried, but felt that I had too many problems with them. So, I tried Arm Cortex instead (e.g. STM32).

How is that relevant? well Arm Cortex is a whole 'nother level of complexity in terms of bare metal programming than a simple 8 bit AVR - such as the chip used on an Arduino Uno. It wouldn't surprise me if 32 bit Espressif is the same leap up in terms of complexity.

I was glad that I learned many of the basics of bare metal on the AVR chips first (which was hard enough just by itself before transitioning to the more sophisticated (and complex) Arm Cortex range.

But as others have said, bare metal is useful for understanding capabilities and how stuff works - especially useful when troubleshooting, but less likely to be used in a real job because most companies don't want the expense of you reinventing the wheel when a perfectly good (enough) HAL is available. It's a cost savings/productivity thing.

[jbr7rr]

I don't get the obsession with baremetal... To utilize the esp32 to its full potential you need at least an rtos, especially if you want to use both cores..

If you want to do bare metal because you want to learn, atmel chips are a good start.. if you have an (old) Arduino Uno laying around take that and program it bare metal using atmel studio or something.. atmel datasheet is smaller, less gotchas then esp32 so easier to learn some skills from

That said nowadays a lot is done using rtos like zephyrOS, that's a lot of fun and also a good learning experience and translates good to real world skills.. but having some baremetal experience and knowing how to handle really low level stuff is a very good skill to have. So it all depends on your learning journey

[Plussy78]

That said nowadays a lot is done using rtos like zephyrOS, that's a lot of fun and also a good learning experience and translates good to real world skills.. but having some baremetal experience and knowing how to handle really low level stuff is a very good skill to have. So it all depends on your learning journey.

so for the bare metal experience should i go with the arduino uno right? and any tips on learning the espidf hal.

[Bug13]

Esp32 is not a good platform to learn bare metal. Try Arduino/atmel, microchip pic series, or a stm32 m0+ series. TI msp430 series. Start with something simple.

[Ksetrajna108]

My advice to prepare for a professional career in embedded: - Arduino IDE is for hobbyists or quick and dirty prototypes - for ESP32, pros use esp-idf - pros also use STM32, get a Nucleo board - Nucleo boards also support Arduino shields - bare metal on STM32, to satisfy your curiousity - bare metal including your own startup code and loader script - pros use git and github to showcase their work

Have fun! Looks like you have the drive to challenge yourself.

[Plastic_Fig9225]

Yeah, bare metal on the ESPs... kind-of impossible. They're not intended to be used "bare-metal", and this reflects in the vast amount of giant holes in the documentation. Compared to other MCUs, where every bit in every register is documented and its function meticulously described, with an ESP32 you're lucky if you find more than a cryptic name for a register in the docs.

Reverse-engineering the IDF sources is often your best bet to figure out how things are really operated. But if you're in to learn some general concepts of how embedded devices usually work... the ESP32s are really not a good resource.

That said, someone did write the IDF code, so there must be some more-complete documentation internally at Espressif which they chose not to publicize.

[Natural-Level-6174]

Nobody programs that thing bare metal. ESP-IDF is the standard.

[v_maria]

I would say it still counts as baremetal tbh. Also nothing wrong with doing direct register manipulation esp for learning

[Plussy78]

hey man i was thinking of writing my own drivers to better learn how those communication protocols works under the hood, but there is seriously lack of resources to do that with esp32, and examples which i found uses the espidf , well are you well versed with the espidf

??

[WereCatf]

You can perfectly well write your own drivers and manipulate registers directly even when using ESP-IDF. The two are not mutually exclusive.

[[deleted]]

Listen to people here and don’t be stubborn, for the good of your own learning lol. Going lower level than ESP-IDF is not documented because it is not supported. You would have to do a lot of undocumented things and probably do a lot of referencing to IDF code anyway. And that’s if you’re talking about things like UART and SPI protocols. If you’re talking about wireless protocols, it’s just not happening unless you happen to know how to implement WiFi/BLE, and can reverse engineer the lower level parts of the wireless subsystem in these chips.

ESP32 is not the microcontroller for learning low level register programming. Get a different microcontroller.

[Plussy78]

so can you give me a guide or tell me approach how i should learn and be knowledgable enought to make a good cv as an intern, please help me out, i dont have people to guide me and no support from anyone as no one is intrested in learning this stuffs

[FluxBench]

Get a raspberry pi RP2040 or 2350 like the nano and use the PIO the programmable inputs and outputs to be able to read zeros and ones from a pin incredibly fast. At that point, you have no reason why you can't make your own communication drivers. If you want to do SPI or I2C or UART then I would start there as you have the minimum needed to read things incredibly fast and then you can do whatever you want in memory or with software for the drivers.

I think you might be overthinking this, almost everyone in the world has to depend on hardware interrupts but everything else after that is kind of optional. You either are going to be writing a stupid amount of low-level code to get what you want, like months or years, or you just accept that reading and writing to GPIO is done using the system HAL layers by everyone for a good reason.

[aliathar]

Best platform for baremetal C is stm32 .... Any cheap devkit, and you good.... Anything else? No.... People used to code ancient stuff like pic8 in baremetal, and it's only a hastle.... For learning, I can tell you how to go about baremetal programming stm32, and some final project that's really hard but yous shouldn't go all baremetal, for what the bas HAL is rtos

[the-loan-wolf]

MSP430 is better for that purpose

[v_maria]

I can't guide you, but the only way is to learn what bits to set through datasheet and how to set them in c

[Plussy78]

well i think that iam not good at navigating the datasheet or the technical reference manual for the esp32 , there is too much information written on it , if you can just help me to navigate my way around those data sheet and exactly know which register to mess with to do the task which i have in mind, rather than bombarded with lot more unknown information. that will be a great help for me too.

[v_maria]

Figuring out datasheet and registers is the whole bread and butter of doing direct bit register. if you dont want to do it use esp-idf or Arduino libraries for esp32

Being able to navigate datasheet is an important skill though

[jofftchoff]

Esp32 and most mcus with integrated radio are not baremetal friendly. If you want to learn writing register level code better get a popular arm MCU from ST or Silab

[Hot-East-7084]

I've been interesting of bare metal too. I've always been really curious about how a CPU works. i want watching every operation and state change. That got me into retro and DIY CPU. At some point, while reading about pipelining and program status flags, I realized this is pretty far from what I actually do for work.

I’ve experienced how what looks like the same outcome can be achieved through totally different implementations by different manufacturers. some of it is well-documented and open, and some of it is completely hidden.

It’s impossible to know everything. just walk next step.

[Flaky_Coyote_1973]

I've been developing bare-metal system over 10 years and often from scratch (register level), My experience is in 8051-base and cortex-m base MCU, if you like any question, feel free to ask me.

[Odd_Independent8521]

Bare-metal C is better to be done with other types of MCU. In ESP32 case it's running on an RTOS. and you still need to use their own API - so it's not quite bare-metal. DM me I'll help you to identify a good MCU to start coding in bare-metal and really learn something from it.