#363

[@WacKEDmaN]

another great, informative, and useful video.. thanks Andreas :) ...what about PSRAM pins..dont they use a few aswell?

[@AndreasSpiess]

I never used WROVER modules. But now I checked: GPIO16 and 17 are connected to the PSRAM. So they are not useable (and also not available on the outside). Two pins less :-( I will update my Excel accordingly

[@WacKEDmaN]

@@AndreasSpiess i have a few boards that use external psram..(eg esp32-cam)..and the pins are exposed as you can turn the PSRAM on and off

[@michaelbishton9439]

I really appreciate your effort to count down which pins can be used for what purpose. Then, near the end, you list the services that can use any pin. Watching this as a newbee, did i misunderstand something? Did you mean any of the actually usable ones or "any pin?"

[@AndreasSpiess]

Of course only with restrictions, for example an input only pin cannot be used as an output.

[@gusercarra]

@@AndreasSpiess Please, I can´t find the excel archive... I´m trying to use an ESP32S3WROOM1 in a nodemcu

[@orparga140]

Maybe the most useful video about ESP-32. You have saved a lot of hours of our lives... 10 hours saved * 1500 vievers( at this moment) = 1'7 years of work

[@orparga140]

5,13 years of work if we calculate 8hours/day

[@AndreasSpiess]

In the end i expect manybe 50'000 viewers ;-)

[@muflah]

I learned this the hard way. It took me about 2/3 days to test all of these and verify my findings with the datasheet and other sources.

[@TD-er]

@@AndreasSpiess Yeah, but as the numbers increase, you may reach users that would never have thought of working with the ESP32 and now they will... So not sure if that still counts as "hours saved" :)

[@ksenyxths]

@@AndreasSpiess 88,223 viewers. I'm a returning viewer, and watch all the video as I'm working on an ESP32 project and I didn't wrote down the pins at the first time. More time saved, as always, well done! :)

[@G6EJD]

Also you can’t use GPIO-12 if an external pull-up is connected to it, say for a sensor, as it prevents the ESP32 from booting and causes a flash error.

[@AndreasSpiess]

You are right! I already corrected the spreadsheet. You have an excellent channel, BTW. I am a longtime subscriber.

[@aviatorbja]

The two best esp microcontroller resources on the planet right here!

[@mazirius11]

I literally ran into some of the problems mentioned in this video last weekend. I couldn't find any useful write ups on which pins to use safely if you only need a few. Again you show the awesome ability to find out topics that need better documentation and provide very useful and condensed information. Thank you very much!

[@AndreasSpiess]

Glad the video was useful for you!

[@LarryKapp1]

Thanks again for taking a confusing subject and making it understandable for all those of us who aren't so tech savvy . Transferring the data sheet info to your own spreadsheet was well worth the time it took too .

[@AndreasSpiess]

You are welcome. I try my best...

[@SebaOPL]

This is extremely helpful to a ESP32 newcomer. Thanks for sharing Excel document❤

[@AndreasSpiess]

You are welcome!

[@robertobrenes5283]

Tomorrow I planned to mill a PCB for a esp32 project, this video came just in time for me to check if I didn't mess things up! Thank you! Your channel is awesome :)

[@AndreasSpiess]

Very good! As said: It might save you some time to redu things...

[@robertobrenes5283]

@@AndreasSpiess RTFD has always been my motto as an electronics student so i love that you always do that!! cheers from Costa Rica!

[@deivissergio2378]

Very good, explanatory video of all I/O functions at once. Many people look for something like this. I own a Company in Germany, and we use the ESP32 in one of our products (IoT devices)... and we use the Internal Hall sensor, as a tricky "Factory Reset" feature. When we finish with all the tests, before send to a customer, we select a "special" condition in the device, and we left the device in such as a "Magnetic bed" for a while... and this performs the "Factory Reset"... so the device is tested and ready for shipment to the customer. (I think this Hall effect sensor, is not very important, but sometimes we can have a good idea to use it... 🤔)

[@AndreasSpiess]

This is really a very good idea! I once used a reed switch with an ESP8266 for a similar purpose but forgot about it. Now I remembered.

[@paulmooij]

A great idea can you share some info? also is ESP32 good for a b2c product?

[@diydsolar]

Please share your experience, thabks.

[@deivissergio2378]

@@paulmooij Hi Paul, in my opinion, this microprocessor is a good solution, with a lot of functions... but it is necessary a lot of "checkings" "workarounds" etc.. if you are working with Arduino IDE for example... (using the tools from Espressif, is much better) Sometimes, without a reason, the processor stops, or perform self reset, etc... (of course it can be something also wrong in the code, or the libraries converted to Arduino IDE). Let's say that the predecessor (ESP8266), has better in performance and stability (and also longer in the market)... But I am happy with this new one... (I use Watchdogs to check if something goes wrong to bring the software again "on track"). Of course, we are still learning with this new processor, and I can recommend it... 👍 (in our company, we started with the ESP32 since 3 months, and already more than 50 devices installed... and no big issues up to now !!)

[@fenixjose17]

Dear Andreas, you are an excellent teacher. Thank you.

[@AndreasSpiess]

Glad you think so!

[@SimjetAU]

Fantastic information..just what I needed. You explain this stuff in the right way as well. one of my favourite videos of yours

[@AndreasSpiess]

Glad you enjoyed it!

[@zolar7a]

Thank you, lots of good information in a 12 minute video. I'm going to print out the spreadsheet and take notes.

[@AndreasSpiess]

Glad you enjoyed it!

[@AragonDubs]

Since I discovered your channel, I am more of a maker than ever, you make it very simple, I love it, and the translations help a lot for a spanish like me. Many thanks Andreas!

[@AndreasSpiess]

Thank you. Yes, I think, Luciana, the translator does a great job!

[@markstafford5586]

Thanks for the info. A group of us are working on a WROVER esp32 board were we are using everything. We have used 70% and are looking at maybe using esp32 variants with even more attached memory. Great video

[@AndreasSpiess]

I never hear that somebody changed the PSRAM chip. I just changed the Flash chip of the early ESP8266-01 boards...

[@pd8559]

My friend with the Swiss accent another nice video. Capacitive switches (touch) are more flexible for our friends in the manufacturing space, think new appliances, than to makers although makers can make use of them too. There are pros and cons to older mechanical switches and the more recent capacitive switches but there is no holy grail or perfect choice. Capacitive switches can be made in a numerous variety of shapes as needed for a particular application and leads to less items needed on the manufacturing BOM but on the cons your need for minimum current to drive them to he back a sense of state change is higher than old mechanical switches as they need to sense a voltage / capacitive drop across the switch surface which means mechanical switch is better if that is your primary design driver is being able to run the switches on lowest possible currents through the switch to sense a state change. Capacitive cons is you have to deal with handing more false positive scenarios than mechanical switches where you simply wait for a signal to come through and just handle debounces. If operating in a wet environment the capacitive switch might be better if your mechanical switch would take permanent damage if the switch got wet as the capacitive switch is more resistant to permanent damage from being wet. Each has plus and minus so our job is to juggle and choose for a specific application but it is nice to know if we need it that it already comes inside the box of tools ESP32 gives us.

[@AndreasSpiess]

I agree, capacitive touch buttons are very flexible for many use cases.

[@danielscheibe8694]

This was actually VERY useful. Thanks for the video!

[@AndreasSpiess]

Glad it was helpful!

[@matthiasthiele]

"and after hours, you think, you are stupid" - been there, suffered too. Great video, thank you very much. I did use a touch port for an alarm clock without any visible buttons. Just touch the clock on the top to switch off the alarm. The user interface for setting the alarm time is via a web page on the smartphone.

[@AndreasSpiess]

Nice idea! Thank you.

[@lukeszy287]

Really good video ! Was great timing as I spent ages yesterday trying to workout why serial1 was crashing the esp32. Thanks again

[@AndreasSpiess]

You are welcome! You are probably not the only ;-)

[@TheDefpom]

@Andreas Spiess I checked into the way I modified the ESP32 Dev Kit V1.0 for the programming failure issue, add a 2.2uF electrolytic capacitor between EN and GND, it programmes fine every time like that without having to press any buttons.

[@AndreasSpiess]

In the meantime I also did the same and it works :-)

[@JohnBaxendale]

Thank you, this is *so* useful! I was just about to pick up an old ESP32 project and start to work out which pins to use, this will save me lots of time :)

[@AndreasSpiess]

Glad you like it!

[@foxtrotbravo1744]

I found the spreadsheet useful, thanks. Frank

[@AndreasSpiess]

Glad it was helpful!

[@jeandilissen4197]

very useful, thanks, saved me a lot of work

[@AndreasSpiess]

Glad it helped

[@rklauco]

Cool project with touch pins? My daughter has a KiwiCo box with RGB led. It was possible to turn on or off the specific colors, so you could create few colors by combination. I sneaked in the ESP32 inside, used the "switches" (removed the contact between them) and modified them to 6 touch switches. By that she can set any color she'd like - the pairs of touch buttons act as color+ and color- for specific channels :) Works quite well :D She likes it a lot. Now she has a night light with variable color.

[@AndreasSpiess]

I can imagine that a combination of colored LEDs an touch is nice for your daughter. And she can tell her friends that she has a cool father who can make such things.

[@GlennHamblin]

Thanks for a great explanation of the ESP 32 I/O! It is appreciated.

[@AndreasSpiess]

Glad it was helpful!

[@Jishan007]

I was waiting when Andreas says 0 pin left .😂

[@TD-er]

It is getting very close to that amount if you start using Ethernet on ESP32. Also nice to see in this table is that the analog pins of ADC2 (those pins that cannot be used with WiFi active) nicely match the pins needed for ethernet. So even if you are not using WiFi as you're using Ethernet, you still cannot use those ADC2 pins for ADC. By the way, I strongly advice you to have a look at the Ethernet options of ESP32 as it really makes for a very swift replying node. In ESPEasy you immediately notice how swift the ESP32 can respond when connected to ethernet. On WiFi it feels quite snappy, but on Ethernet it is really a completely different story.

[@0dium.]

1 pin left .. for the led blink project :)

[@AndreasSpiess]

@Gijs: Which library do you use? I just got Ethernet boards...

[@TD-er]

@@AndreasSpiess See here: github.com/letscontrolit/ESPEasy/blob/mega/src/src/ESPEasyCore/ESPEasyNetwork.cpp I simply use the "ETH.h" from the espressif/arduino-esp32 github.com/espressif/arduino-esp32/blob/master/libraries/WiFi/src/ETH.h

[@TomBelpasso]

Great video. I use the Hall effect as a magnetic switch. I have some TTGO Lora32 boards with display and uSD card interface all of which I want to use. Plus a third UART so I don't have many pins to spare. The board has no physical input switch, only a power switch and reset. The nice thing about using the magnetic sensor is that I don't have to put a hole in the 3D printed case. I am running Micropython because much of my code is portable between PC, RPi and ESP32 and I hate working in C. The Hall sensor value varies a lot between boards and other factors which I haven't researched, so on startup I take multiple readings and average them to calculate an zero offset. This assumes no magnet is around. The magnets I am using are large rectangular ceramic one I got from Harbor Freight. The poles on the large faces. If I hold with one side up, I get a positive value, flipping it over I get a negative value. Putting the small side of magnet against the screen give me one value and the large side gives me a much larger value. So in effect I have multiple switch selections. I plan on having the display turn off after a timeout and only turn it back on when a magnet is detected. My Python code implements a value map function which is just like the C Arduino map function. I map the range to several levels. Right now I use it as 4 switches, Small side plus and minus and large side plus and minus. If you are interested I will upload the Micropython code to Github. Keep up the great work, sometimes it is like you read my mind.

[@AndreasSpiess]

To use the sensor as an input is a good idea. Also another viewer uses it to reset the chip. I remember I used a reed switch to avoid a hole for a switch. If the ESP chip is close to a wall this is a good idea.

[@bbogdanmircea]

OMG this is amazing. I learned this the hard way. I would add that depending on the board, some other pins will be blocked or have limitations during boot, so checking the schematic of the board really helps. Is the xls available somewhere?

[@AndreasSpiess]

kzbin.info/www/bejne/goqQYnd-id2Fd80 ;-)

[@wjn777]

Great video, I could have saved many hours of debugging by either RTFM or watching this video

[@AndreasSpiess]

:-) Thank you!

[@Iceteavanill]

Thank you for making this Video. Just in time for me to choose which GPIO Im gonna use in my project.

[@AndreasSpiess]

So the video was timely...

[@batica81]

Thank you very much for this useful video! I tried porting a project (morserino 32) to a different version of esp32 board and it was very tedious (and unsuccessful) because of all the pin differences. It also uses those capacitive touch pins which adds to complexity. Maybe I will try again now :)

[@AndreasSpiess]

Interesting project. Maybe I will also build one.. Currently I build an K3NG Arduino CW Keyer because my IC-7300 only supports Iambic Mode B and I am used to mode A :-(

[@lmarloe]

Espressif introduced ESP32-C3 based on RISC-V. Waiting for review when the board comes out 👍

[@AndreasSpiess]

And the supporting software. HW without SW is not very interesting for me...

[@tonybell1597]

Perfect guide Andreas.... thanks....

[@AndreasSpiess]

Glad you liked it!

[@rklauco]

The part about GPIO0 and 2 is something I needed 3 months ago when I was doing my LCD clock project :( Thanks - better late than never :)

[@AndreasSpiess]

Maybe you need other tricks later on. I use this excel quite a lot.

[@Designments]

Your channel is an absolute gem. No nonsense, concise, well researched videos are rare, and you consistently deliver. Thank you!

[@AndreasSpiess]

Glad you like my content!

[@anonymoususer6448]

Can ADC2 pins be used as GPIO when using WIFI? As usual, a pure-gold video by Andreas Spiess. A real engineer in everything he does. It was not clear to me if we can freely use the ADC2 pins as GPIO when using WIFI (6:26 into the recording) Maybe you can elaborate? thanks again for the great podcasts

[@AndreasSpiess]

Wi-Fi only uses the ADC function. All other functions are ok.

[@merlin_V2]

I was going mad, not finding this limitation anywhere else. Thanks for the clarification! I really needed those I/Os

[@sharpbends]

I used touch pins connected to case screws as rudimentary input device for up down back enter commands etc on GPS alarm clock :-)

[@AndreasSpiess]

Very good idea!. Hidden and no additional parts needed.

[@jackansi]

Thank you!

[@AndreasSpiess]

You're welcome!

[@aviatorbja]

So good. No ads till the end. This channel is too good to be true. Very interesting and informative.

[@AndreasSpiess]

Glad you value my decision for the ads...

[@johnerrington9371]

The DACs appear to be a very high impedance output. I have found it essential to use an external amplifier, and not just any amplifier but one with a very low leakage current back to the DAC - a non inverting configuration rather than an inverting buffer.

[@AndreasSpiess]

Good Info. I did not check it. Just with the oscilloscope.

[@sunshinelabz]

Very useful video... Looking forward for more cool tech videos

[@AndreasSpiess]

Should come. It is what I can ;-)

[@boieperez3768]

what a great video thanks for sharing

[@AndreasSpiess]

You are welcome!

[@ayrtonestrella]

This video y extremely useful! I'm so grateful, Andreas! I have been researching for weeks in an attempt to learn how to choose the pins and which pins I should not use. Your video is the most explicit and easy-to-understand resource I have ever seen for the ESP32. I actually decided to update my ESP32-WROOM schematic symbol to distribute the pins accordingly, for easier PCB designs. I really appreciate the work and effort that you put in, and I'm looking forward on becoming your supporter on Patreon. Thank you, thank you very much.

[@AndreasSpiess]

You are welcome. And thank you for your feedback!

[@vex9596]

Amazing work, as always! :D

[@AndreasSpiess]

Thank you!

[@karelholl2568]

Thank you for the excel sheet.

[@AndreasSpiess]

You are welcome!

[@royballantine6788]

Thanks!

[@AndreasSpiess]

Thank you for your support!

[@butterfly_free]

THANKS

[@AndreasSpiess]

You are welcome!

[@fschirott]

Thanks for sharing, this video will definetely save me a lot of time.

[@AndreasSpiess]

Glad it helps!

[@RWB123]

Excellent video 📹

[@AndreasSpiess]

Thank you!

[@Hossein_Ash]

Thank you

[@AndreasSpiess]

You're welcome!

[@kcmichaelm]

Excellent as always, thanks Andreas!

[@AndreasSpiess]

Thank you!

[@sichel94sam]

This video should be called "Ultimate ESP32 Pin Guide"

[@AndreasSpiess]

Thank you. Maybe I will change the title...

[@middelbh]

What about the GPIOs that are not in the DEVkit bat are available on the bare ESP32 WROOM? I think there are some more IO's?

[@AndreasSpiess]

You can check with the Excel which ones are not connected on your dev board.

[@nickhubbard3671]

Very useful! Thanks.

[@AndreasSpiess]

You're welcome!

[@EmmanuelLieurain]

A very useful wrap-up, thanks

[@AndreasSpiess]

You are welcome!

[@muflah]

About the touch pins, they're most certainly not worth trying in a commercial project. The sensitivity is low (try putting the conductor just behind a 4mm acrylic sheet) and there is a lot of noise.

[@AndreasSpiess]

Thank you for sharing your experience!

[@s.husain6125]

Nice sir please make tutorial on how to calibrate analog pins in esp32 becacuse this is main problem in esp32 which effects the analog sensor accuracy in simple words how to solve non linear analog signal in esp32 and improve sensor accuracy

[@AndreasSpiess]

This is not a topic for this channel. Too easy, and probably not very useful in most cases.

[@vincentstragier6628]

4:41 the I²S is framed instead of the I²C.

[@AndreasSpiess]

You are right. Thank you.

[@alanesq1]

May be worth doing a similar video regarding pin usage on the ESP32Cam module? I have found that if using the sd card it is a real pain as it takes control of the onboard flash as a data pin (flashing it when accessing the sd card) and leaves no free gpio pins but it turns out you can use "1 bit mode" for sd card access which only uses 1 of the 4 data pins and so whilst access is slower it means you can still use the onboard flash and pins 12 and 13 are then free for gpio use. Note: to enable 1 bit mode use the command "SD_MMC.begin("/sdcard", true)". Note: you may need to re-assign the io pins as input or output that you wish to use after the sd-card is initialised as it can re-assign them.

[@AndreasSpiess]

You should see the SD card pins in the Excel. I never used SD cards with the ESP32

[@WistrelChianti]

Darn... I had 34 and 35 mapped as outputs in my plan... back to the drawing board...

[@WistrelChianti]

and had in mind "something" (wasn't sure what - possibly some sort of secret "switch") with the Hall sensor, but already got those pins mapped as inputs so there goes that idea (indeed it wasn't particularly responsive/reliable in tests for me either).

[@peter.stimpel]

when I purchased my very first esp32, I was quite in Arduino nano before. The first steps with esp32 were so confusing. Often you stick with an idea, but cannot get it work because of a secondary use of the selected pin. I wish I had such an excel at that time...instead I have a few more gray hair from it. For inputs, I started using I2C connected expanders. Many pins, and no hassle with double function ...

[@AndreasSpiess]

If you stick to the „save“ pins it should work. I never needed port extenders as far because I always had enough pins. But you never know...

[@PanosKontogiannis]

great video! Thanks a lot!

[@AndreasSpiess]

You are welcome!

[@williamdenbeste9703]

Perhaps one more column: the state of the pin after reset - look it up and you'll see that some pins initialize low and some initialize high. Ouch! Could be a problem for some circuits when the ESP32 GPIO pin goes high at reset.

[@AndreasSpiess]

You are right. So far I never had problems with that, but something bad can hapen. Maybe somebody adds the column.

[@WooShell]

".. and who doesn't use WiFi on their ESP?!" - oh, only those weird Swiss engineers with their Ethernet connected ESPs... ;-) Regarding the Hall sensor - what exactly are you expecting to see on your oscilloscope? The Hall function is multiplexed on those pins and can not be read from outside, but simply piping the output from a hallRead(); to the serial output should show a significant change when you put the magnet near the shielding can.

[@AndreasSpiess]

You are right. It shows a change, but only if you are very close to the chip. This is where I see the limitation.

[@bradstewart2024]

I think most of the pins are available as GPIO's with the new ESP32-S3. And more are available.

[@AndreasSpiess]

Maybe we will need a similar chart for the S3 (and other newer ESP chips)

[@bradstewart2024]

@@AndreasSpiess Yes, may be a good idea. It seems to be more of a standard. All GPIOs are input and output. And there are more pins ("we want more").

[@PedroLamas]

Excellent video, really useful stuff!! Any chance of doing one of these for the ESP8266 D1 Mini?

[@AndreasSpiess]

I think you should find the info using Google. It is much simpler...

[@davebareham1075]

Great video - where do the mounting boards (see beginning of video) come from - Ali Expeess ?

[@AndreasSpiess]

Usually, you find links in the video description.

[@PeteDubler]

Another great video. Do you have a similar spreadsheet for the ESP32-S3?

[@AndreasSpiess]

No. But it should be easy to adapt using the S3 datasheet

[@PeteDubler]

@@AndreasSpiess it should be but as you know, our friends at ExpressIf have renamed many of the pins and their manuals have become more difficult to read compared to the manuals for S2 chips, which were so much better than the early manuals. That in itself is worth a video 🤔 And, oh yes, ExpressIf has two different pin-out diagrams avail from their website for the ESP32-S3-DEVKIT-C1 One with the RGB LED on GPIO 38 and one that is correct with it on GPIO 48. (Lots of time wasted on that...)🥺

[@thomascziesla3768]

Useful=true

[@AndreasSpiess]

Thank you!

[@klassichd10]

Thank you very much. This table is extremely helpful! The pin assignment of ESPs is anything between confusing and a nightmare. Do you have experience with the dediceted pulse counter inputs?

[@AndreasSpiess]

No, I never used them so far.

[@PHamster]

I2S was highlighted at 4:43! It’s the I2Spiess interface :)

[@AndreasSpiess]

You are right. My mistake.

[@PHamster]

@@AndreasSpiess We're only human... we generate erratas as well

[@RandomPerson494-12c]

Does Bluetooth/BLE occupy any pins like in case of Wi-Fi ?

[@AndreasSpiess]

Wi-Fi and BLE use the same radio.

[@vu2bhf]

Thanks a lot

[@AndreasSpiess]

Happy to help

[@nicolasoliveras4601]

very good

[@AndreasSpiess]

Thank you!

[@derisis13]

What about I2S? I know that in the STM32F405 it can be mapped to pins where SPI can be mapped, but what about the ESP32? It is a really handy high-speed shift register and by the way a common audio protocol...

[@AndreasSpiess]

I never used I2S, so I do not know.

[@cicicok]

You forget to include CAN bus controller in your table. So sad that this feature of ESP32 is highly overlooked. GPIO5 will act as CAN_Tx. GPIO4 will act as CAN_Rx

[@AndreasSpiess]

So far I never used CAN bus. Where do you use it?

[@АндрейНик-р3к]

Спасибо тебе, добрый человек! Очень полезная информация. Ты очень сильно мне помог!!!

[@AndreasSpiess]

Не за что

[@JohnSmith-iu8cj]

Wait all ADC2 pins can not be used when using WLAN? Really?

[@JulianGrammer]

Yet another highly informative video. Thank you. I couldn't stop laughing at so few pins available for general programming when comparing with your video #159 at 1:40. Amazing what one can learn in three years.

[@AndreasSpiess]

Not general purpose does not mean not useable. It just means: Pay attention!

[@frank20a]

Thank you for the video! Are these all applicable to the ESP32-S3?

[@AndreasSpiess]

No. Watch my newest video…

[@mizarorion]

He estado buscando por internet y no había encontrado nada, solo el datasheet pero la verdad que no sabía como interpretarlo, este video me explica lo que estaba buscando a la perfección y seguro que me has evitado muchas horas de sufrimiento, lo he guardado como oro en pacho. MUCHAS GRACIAS

[@AndreasSpiess]

Glad the content was helpful!

[@warperone]

extremely helpful sumay - i am a patreon btw and well worth it - i recommend others buying a virtual coffee for Andreas each week as well ;-)

[@AndreasSpiess]

Thank you for your support! Glad my videos are helpful.

[@hoodafukisalice]

This is gold for developers using ESP32. Thank you for sharing the Excel sheet Andreas.

[@AndreasSpiess]

Glad it was helpful!

[@academicpachyderm5155]

Holy cow. Thank you so much! I almost ordered my own esp32 breakout boards yesterday, but after watching this I'm definitely adding some asterisks to my silkscreen pin numbers. I'm also trying to start experimenting with the esp32-s2, so I'll be on the lookout for "gotchas" there, too.

[@AndreasSpiess]

The S2 is too new for me...

[@wilfredosandovaldelgado3690]

I have use GPIO 0 and there is no problem, thanks for the secrets.

[@AndreasSpiess]

If it stays high during boot there is no problem...

[@wilfredosandovaldelgado3690]

@@AndreasSpiess sorry Andreas, maybe I was not rigth, I wanted yo say, that in My proyect, I am ussing the GPIO 0 to activate a triac whit a low signal and there is no problem. Till the moment, by the way thanks for the tutorial with structs for RTOS programing, I have to say, that Open My mind to do some more elegant, I'm not programer, just a dreamer. Don't speak English, but try to, jejej. I'm from Colombia and thanks to You and others i'm breaking the wall of knowledge, thank you for so much.

[@francoisgervais1]

Not sure if it would be considered as a cool project but I use the touch sensor for leak detection: github.com/fgervais/leak-detector

[@bennguyen1313]

Seems different flavors of the ESP32 chip (i.e. Risc-V vs LX6) may have different options available... Will the compiler flag an error if one tries to enable pull-up on a pin that only has a pull-down option? ex. button = Pin (22, Pin.IN, Pin.PULL_UP) BTW, do you generally use micropython or c for most of your esp32 applications?

[@AndreasSpiess]

The Arduino IDE cares about the different architectures. And you have to know the function of the pins. No help from the compiler. I use C++

[@keen2461]

Andreas does everything I wish I had the time to do. I'm also an EE but don't have time to investigate and experiment as Andreas, so I live vicariously thru his videos.

[@AndreasSpiess]

Maybe if you become as old as I am you will have time...

[@marinehm]

What are you using to program your ESP32? I’ve had 2 chips that were knock-offs and didn’t work. Now I’m getting another from Espressifs LOLIN store on AliExpress.

[@AndreasSpiess]

I use the Arduino IDE. And so far I never saw knock-offs.

[@fabiancastano6233]

thank you very much, so interesting information, I have a question about the use of GPIO2, in some development boards I saw that they connect a LED to this pin and it allows to program the ESP32 correctly, maybe is it not problem to connect this pin as output in the projects?, I have a project where I'm using all the pins and need to connect a buzzer, do you think I can to use GPIO2 pin? and, I need to record sound to analyse some data through I2S protocole, can I use the flash that is incormporate in WROOM to save some of these data? Thank you again

[@AndreasSpiess]

GPIO2 has to be floating or low for flashing. And I would hope you can use the PSRAM to save some data. I never used it.

[@electronic7979]

Helpful video. I liked it

[@AndreasSpiess]

Thanks for liking

[@edward17829991]

Is the built-in hall effect sensor capable of sensing current usage or as input interface when sealed in a water tight box?

[@AndreasSpiess]

I do not think so.

[@slacky00]

Can you make one for the old Esp8266 too?

[@TD-er]

The ESP8266 is well described in a number of blog posts. See the links mentioned here: espeasy.readthedocs.io/en/latest/Reference/GPIO.html#best-pins-to-use-on-esp8266 What makes it even harder on the ESP8266 is that some pins also toggle at boot, which makes them unusable for switching things (e.g. a relais) unless you add some filter over them to filter out the very short pulses.

[@Rob_III]

@@TD-er Thanks for the link! Though a video by Andreas on the topic would be appreciated anyway!

[@rodstartube]

As always very usefull. I will print a T-shirt with that excel file so i have it handy.

[@AndreasSpiess]

:-))

[@paulvint]

This is great - good video, and more importantly, thanks for sharing the spreadsheet. I've been meaning to export that from the datasheet for ages, and it's a great help!

[@AndreasSpiess]

Glad it was helpful!

[@JessGade]

Another exotic observation: Keeping pins high during deepsleep doesn't seem to work for all GPIO pins. For instance using pin 17 doesen't work -but using eg. pins 25 or 26 do! ( using "gpio_hold_en((gpio_num_t)OUTPUT_PIN);" )

[@AndreasSpiess]

Thank you for the addition. I never used this feature.

[@MrBobman49]

I know MTDI or GPIO12 isn't in your Priority List, but this pin can be a real "GOTCHA". I was using this with an Optocoupler and a 10K pullup resistor and thought I had "Bricked" the Dev Board. Upon further examination, if you tie a pullup to GPIO12 during boot, it tells the CPU to run at 1.8V which doesn't let it talk to the Onboard Flash running at 3.3V. Now, with any design I stay off the Strapping Pins!

[@AndreasSpiess]

You are right. Now I included it in the Excel sheet.

[@jenniferw8963]

GPIO6 - GPIO11 -- External Flash. I ordered the ESP32 S3.. so are these pins tied up or free? I didn't realize we get so few pins.. seemed like a lot at first lol. My project needs a lot of pins.. 13 pins for push buttons and rotary encoders.. a dozen pins for PWM writes to LED for DIY Vactrols. And 2 pins for I2C to MCP23017 to drive a dozeen 10ma reed relays.

[@AndreasSpiess]

Maybe you search for "port extenders"? You find the pin assignment of the S3 in its data sheet. So far, I have no excel sheet.

[@electronicstv5884]

Super!👍😅

[@AndreasSpiess]

Thanks! 😃

[@anthonyjahman9704]

Hey, nice video, i need help to connect a nokia 5110 display to esp32 lolin weos, can you make a video about esp32 lolin wemos and NOKIA 5110 DISPLAY?

[@yadalapurapuapparao9645]

Great explanation, I have one question. Can we use DAC(GPIO25,26) along with the WiFi driver..? please let me know if any issues. Thanks.

[@AndreasSpiess]

I never used the DAC, so I do not know.

[@jeanyluisa8483]

One more thing that has cost me some time is that the "GPI" Pins (34 - 39) have no internal pullup and pulldown function. So e.g. pinMode(34, INPUT_PULLUP) does not cause an errormessage, but also not pull the pin up..

[@AndreasSpiess]

Good point. Thank you. I will update the Excel.

[@HVICTORI1]

Thankyou Mr. Andreas. Can you help us with something like "#3XX How to use an SFP interface with ESP32 o STM32" or something else.

[@AndreasSpiess]

I do not know anything about SFP. But I found this: www.reddit.com/r/esp32/comments/hdxugi/esp32_sfp/