#315

Рет қаралды 115,933

4 жыл бұрын

Computers crash if they do not have enough voltage. Li-Ion batteries could explode during charging if they were deeply discharged. How can we prevent such events? We need so-called voltage supervisors. Cheap parts with a big effect, which usually do their job in the dark. Let’s tear them to the light and protect your ESP32 or Arduino from not booting correctly and your Raspberry from a crash. We will use KA75330, KA75450, and TPS3839 for our experiments.
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Пікірлер: 459

@jvgorkum 4 жыл бұрын

Yet another gem, I could use this for my supervisor (when my energy is to low)

@AndreasSpiess 4 жыл бұрын

:-) The question is then how he is wired: On at low level or off at low level...

@jaynottelling5892 4 жыл бұрын

Might need the gas soldering iron!?

@kbxbr 4 жыл бұрын

Mr. Spiess thank you so much for all your well-made incredible videos! Cheers from Brazil!

@AndreasSpiess 4 жыл бұрын

You are welcome!

@joakinsa 4 жыл бұрын

This is exactly the problem I found some days ago with my project and this video just came from nowhere! Already ordered TPS3839 after the end of the video. Thank you!

@AndreasSpiess 4 жыл бұрын

I hope it will help!

@waltsteinchen 4 жыл бұрын

Thank you Andreas for another really very userful video! ... I'm using your videos very often as a "reference" to look up things if needed in my projects.. this is definitiv one I'll remember ;-)

@AndreasSpiess 4 жыл бұрын

Sometimes, I use them as a reference, too ;-)

@TheLinuxBust 4 жыл бұрын

Excellent video, thank you for sharing! I hadn't heard of voltage supervisors before, but now that I do, it feels almost too obvious that there are parts that do this specific task!

@AndreasSpiess 4 жыл бұрын

You are welcoome!

@craiglarson2346 Жыл бұрын

One small thing I learned from exploring the voltage supervisors: a voltage supervisor is not a battery supervisor. When these devices turn off (Output goes to zero volts) the VCC/GND supply current increases substantially. The KIA7029’s I’ve been testing consume very little amperage when output is high. As a dropping supply voltage approaches the 2.9V trigger the device current use is about 16 uA. Once output goes to zero the device current rises to over 500 uA. Andreas solves this problem too with the N-channel FET idea at 12:30 in the video - it just took me a while to understand it. Hope this helps other viewers of this great channel.

@AndreasSpiess Жыл бұрын

I have to admit: I did not focus on the powr supply of these parts. So I learned something. Thanks!

@Hackvlog 4 жыл бұрын

Thanks for informational video, answering questions "What? Why? and How?". For simple microcontrollers, like ATMegas, brown-out detection could do the job. It holds the core in reset-state, when voltage is below the threshold. There is limited amount of threshold values (ATMega328p for example has programmable thresholds of 1.8V, 2.7V or 4.3V). But even for these simpler micros, external supervisor has benefits of wider range of thresholds, start-up delays and other specs. Just thought to add this tidbit, even though this might not be as applicable to ESP and Raspberry Pi.

@juanmontes8905 4 жыл бұрын

I know I heared about that internal undervoltage protection module before

@BerndFelsche 4 жыл бұрын

BOD seems effective for loss of power but not so much for slow recovery.

@McTroyd 4 жыл бұрын

I've seen in other places that, at least on AVR microcontrollers, the brown-out detection can cause an increase in idle current draw on the order of milliamps. That could still present an over-discharge problem in a battery-operated circuit. The FET-based switching solution Andreas presents here, using one of these supervisors, could still be useful in that case.

@donpalmera 4 жыл бұрын

@@BerndFelsche >BOD seems effective for loss of power but not so much for slow recovery. That would be part of the Power-On-Reset block.

@AndreasSpiess 4 жыл бұрын

You can fool the Arduino, too, if you want ( kzfaq.info/get/bejne/bLaWZtOKmK3ccoE.html )

@tonysfun 4 жыл бұрын

Very practical! This should prevent a lots of problems! Thanks again Andreas!!! Have a great week!

@AndreasSpiess 4 жыл бұрын

Thanks. You too!

@piebebakker2447 4 жыл бұрын

Thank you Andreas. Exactly what I needed for my solar powered ESP32 Lora nodes, who stop when the sun light has been insufficient during winter and never come back again as result of the ‘limbo’ state.

@AndreasSpiess 4 жыл бұрын

I think this is a very good application.

@puriap250 3 жыл бұрын

This was so absolutely informative! I had never thought about this. I always put large capacitors on my ESP boards because they are sensitive to power but it never occurred to me that the power-up could also cause bugs. Maybe I've been lucky so far. I will definitely use the capacitor+resistor on reset pin trick next time I'm designing a board. Also I had no idea these voltage supervisor chips exist. They are so useful! Unfortunately they don't seem to be available where I live but it's still good to know that they exist. Maybe I can find similar parts. Thanks a lot for this video.

@AndreasSpiess 3 жыл бұрын

You find many suppliers for such parts. They are widely used.

@DimitrisPaterakis1 4 жыл бұрын

Thank you for the video. I am using the MAX809S (2.93V) for this purpose because it costs nothing ($1.51 50pcs). It has push-pull output (no need for pull-up resistor).

@AndreasSpiess 4 жыл бұрын

Good choice. Thanks!

@easynow6599 4 жыл бұрын

thanks for the advice, but i have a question: according to datasheet: "The MAX803/MAX809 have an active-low RESET output", but esp32 is activated when reset pin is high..so how it can be used for esp32 activation?

@spehropefhany 4 жыл бұрын

Easy Now MAX810 has the inverted output. Needless to say you need to be very careful to pick the correct voltage range including tolerances.

@DimitrisPaterakis1 4 жыл бұрын

@@easynow6599 According to the datasheet of MAX809: "RESET output remains low while VCC is below the reset voltage threshold, and for a reset timeout period after VCC rises above reset threshold". We talk about ENABLE pin of MCU and not reset. Don't be confused.

@AndreasSpiess 4 жыл бұрын

I mentioned it in the video that the "reset" pin on the ESP32 is called "enable" pin.

@mrx.2233 3 жыл бұрын

Always enjoy watching your videos. Thanks for the good work.

@AndreasSpiess 3 жыл бұрын

Glad you like them!

@sarahjanegray 3 жыл бұрын

Thanks for this video, Andreas. As well as explaining how votage supervisors work and how to use them, through some of your demos and charts in this video, you have helped me cement some understanding about power issues that I had been struggling with understanding what was happening some times in my own circuits using MCUs. Now I need to go and buy some of these so I can use them in my circuits! Thank you. Stay safe.

@AndreasSpiess 3 жыл бұрын

You are welcome. Fortunately they are not too expensive ;-)

@sarahjanegray 3 жыл бұрын

@@AndreasSpiess Indeed. Apart from the KA75330 (which I have purchased from AliExpress), I seem to be having problems sourcing them. I need through-hole versions rather than PCB friendly versions and would like to have a selection of them. Just wonder if you could recomemmend a good place to source the KA75XXX or equivalents)? Thanks.

@AndreasSpiess 3 жыл бұрын

I bought a few MAX809 and a TL7702 also from AliExpress. But I never used them so far.

@sarahjanegray 3 жыл бұрын

@@AndreasSpiess Thanks Andreas. I'll take a look.

@blaketurner9389 Жыл бұрын

Thank you. So much useful and practical information in all your videos 😊

@AndreasSpiess Жыл бұрын

Glad you think so!

@pt4ve8cw3l 4 жыл бұрын

Thank you! That's a very interesting chip. So useful! You are a great teacher.

@AndreasSpiess 4 жыл бұрын

You are welcome!

@BerndFelsche 4 жыл бұрын

Thanks for introducing the device type. Perhaps a follow-up video comparing them to brown-out detection built into microcontrollers?

@AndreasSpiess 4 жыл бұрын

Maybe in hte future. I looked at the brownout detector of the ESP32, but it was not well documented. Especially not with the Arduino IDE. It seems that the Arduino also can be fooled ( kzfaq.info/get/bejne/bLaWZtOKmK3ccoE.html )

@KDM-Reloaded 4 жыл бұрын

This is what i have been waiting for a long time. Thanks👍

@AndreasSpiess 4 жыл бұрын

You are welcome!

@craiglarson2346 4 жыл бұрын

Andreas, @ 8:50 you give a gift. The RC circuit solves my problem and stability returns! (R=68K, C=10uF)

@AndreasSpiess 4 жыл бұрын

Good to know it helped!

@pierrefpv 4 жыл бұрын

Perfect timing! I just ran into a similar issue this weekend setting up a ESP32-cam as a doorbel. When the bel is pressed the voltage drops and resets the board, but leaves the camera in a weird state and needs a hard reset. Sometimes this also happens when flashing OTA.

@AndreasSpiess 4 жыл бұрын

I hope such a part will help!

@nirmalkumarvermabachchan632 4 жыл бұрын

A great informational video. Thanks a lot. I was searching for the same.

@AndreasSpiess 4 жыл бұрын

You are welcome!

@duncanx99 4 жыл бұрын

Excellent advice and very informative. Thanks Andreas...

@AndreasSpiess 4 жыл бұрын

You are welcome!

@Excalibur32 4 жыл бұрын

This sounds like exactly what I need. Thank you very much!

@AndreasSpiess 4 жыл бұрын

You are welcome!

@tonybell1597 4 жыл бұрын

Useful little devices, thanks Andreas

@AndreasSpiess 4 жыл бұрын

True! You are welcome.

@marinehm 4 жыл бұрын

This was awesome. I think it explains what happened to my Raspberry Pi when the mains cut off during a bad storm.

@AndreasSpiess 4 жыл бұрын

The Raspberry has a different problem because it has an operating system and has to be shutdown, not only switched off. At the end of the video I showed how it has to be done for a Pi.

@frogeye22 4 жыл бұрын

Thanks, a very interesting and well presented lesson.

@AndreasSpiess 4 жыл бұрын

You are welcome!

@ristomatti 4 жыл бұрын

These seem very useful but simple to use at the same time. Off to shopping, thanks!

@AndreasSpiess 4 жыл бұрын

:-) Not an expensive buy, fortunately...

@Really2950 4 жыл бұрын

This was super useful information. Many thanks

@AndreasSpiess 4 жыл бұрын

You are welcome!

@mordinkainen1844 4 жыл бұрын

very useful, as always! Thank you Andreas.

@AndreasSpiess 4 жыл бұрын

You are welcome!

@reinholdu9909 4 жыл бұрын

Andreas .. YESSS! 15min listening to KZfaqs most tech savy "swiss accent" and the day is gonna be "GUAT"!

@AndreasSpiess 4 жыл бұрын

:-) Today, I had to do a little more. I had to give a "Indoor Cycling" class with my daughter...

@recomoto 4 жыл бұрын

@@AndreasSpiess having quality velo time :D

@AndreasSpiess 4 жыл бұрын

So you must be Swiss ;-) (Velo)

@PilotPlater 4 жыл бұрын

Thanks Andreas, this is really helpful

@AndreasSpiess 4 жыл бұрын

You are welcome!

@adityapandya8098 2 жыл бұрын

This video is so amazing for me keep it up sir and keep make us knowledgeable. Thanks

@AndreasSpiess 2 жыл бұрын

Glad you liked it! Thank you.

@ivandidomenico3281 4 жыл бұрын

Very very good Andreas! Good video as always 😉

@AndreasSpiess 4 жыл бұрын

Thank you!

@nogrend 4 жыл бұрын

Thank you for the nice-to-know-stuff!

@AndreasSpiess 4 жыл бұрын

:-)

@JoelvdLoo 4 жыл бұрын

Very interesting, thanks Adreas!

@AndreasSpiess 4 жыл бұрын

You are welcome!

@georgegeorgiou5229 4 жыл бұрын

Very nice video, useful and informative!

@AndreasSpiess 4 жыл бұрын

Thank you!

@wileecoyoti 4 жыл бұрын

This is great, thanks! I use these and a few others that are latching and/or keep the voltage divider outside of the main chip so as to be able to tune the cutoff points. I have a few components that become unstable at weird points like 3.85v, and others that need to be effectively removed from the circuit until the battery has had a chance to get back up to a decent level.

@AndreasSpiess 4 жыл бұрын

Maybe a list of your parts would be interesting for other viewers?

@wileecoyoti 4 жыл бұрын

@@AndreasSpiess oops! Thought I had mentioned it, but the MAX8354/835 series is my go-to for latching. Here's a little more information to make up for not mentioning that r in the first message :) The internal reference is only 1.2v giving it a very broad range. It's extremely low power consumption (I usually see 1-3uA), so perfect for battery devices. A bit more expensive and SMD, so as always depends on your application. 834 if an open drain, and 835 is push/pull. Either can use separate VCC and monitored voltage on case you're working with things outside of its native VCC range.

@AndreasSpiess 4 жыл бұрын

Sorry for missing the connection to another message. I get a lot and I am already quite old ;-)

@javiercuellar73 4 жыл бұрын

Excelente information Andreas!! Thank you very much!!!!

@AndreasSpiess 4 жыл бұрын

You are welcome!

@timmyfingaz100 Жыл бұрын

RGH (reset glitch hack) on the xbox 360s was fun. The original Jtag hack used a few resistors and small diodes, not much cost at all! Thanks for the great info, I am looking into circuit protection atm!!

@AndreasSpiess Жыл бұрын

You are welcome!

@devluz 4 жыл бұрын

Great video. That was exactly what my solar temperature sensor was missing!

@AndreasSpiess 4 жыл бұрын

Fortunately, not complicated to add ;-)

@g3i0r 4 жыл бұрын

I had this startup problem with an ESP8266 design. Now I finally know what the problem is! 😎

@AndreasSpiess 4 жыл бұрын

And not difficult to solve...

@webslinger2011 4 жыл бұрын

Very informative. I knew my esp32cam resets due to low power on my arduino toy mobot but didn't know how to prevent it. Had to power it separately. Thanks for sharing this.

@AndreasSpiess 4 жыл бұрын

It is always better to use a stable power supply...

@chaughten 4 жыл бұрын

Your videos are the best, I learn lots thx!

@AndreasSpiess 4 жыл бұрын

Glad you like them!

@lmamakos 4 жыл бұрын

Thank you for bringing this topic to our attention! I knew these things were out there, but never thought about their application in my hobby projects. Now I have yet another thing to put on my long list of stuff to think about! (Also, I think your battery schematic symbol is backwards?)

@AndreasSpiess 4 жыл бұрын

You are right. A few viewers "complained" about the battery symbol. I was too lazy to look it up because I felt it was not so important (for me)

@usmanasghar2567 4 жыл бұрын

Beautifully explained

@AndreasSpiess 4 жыл бұрын

Thank you!

@certified-forklifter 4 жыл бұрын

thank you for another awesome video!

@AndreasSpiess 4 жыл бұрын

You are welcome!

@chuxxsss 4 жыл бұрын

Enjoy this one Andreas, very claming. Need to do a vlog tomorrow on my old spot welder. Have a great week. And as we say in Australia, don't forget the toilet roll. Lol

@AndreasSpiess 4 жыл бұрын

I can imagine, in a large country like yours, this detail is even more important than around here ;-)

@RickB3n 4 жыл бұрын

Very useful! Thank you, greetings from Italy.

@AndreasSpiess 4 жыл бұрын

:-) I hope you are still healthy!

@RickB3n 4 жыл бұрын

@@AndreasSpiess Thanks, fortunately I live far from the red zone. However, we must be careful.

@sevenacregreen 4 жыл бұрын

This solution is good for the esp as it can reset everything even if you use third party code like tasmota. I have found that bod on chip can be troublesome in some applications and is different for each cpu this gives the same solution for all and you can debug it with a scope. One point on the input resistor divider for the comparator in the devices. The voltage reference will need some headroom to operate so needs to be below the threshold voltage. A good explanation of their operation, thanks Andreas.

@AndreasSpiess 4 жыл бұрын

I also did not find out how to use the BOD signal in code. And BOD only works if the MPU still works, so above 2.3 volts.

@sausagehider 4 жыл бұрын

Very useful to know. I did not know these things existed. I had the problem with powering ESP8266 and solar power. While I'm away at work, if the voltage drops the ESP locks up and sometimes I have to wait for over a month before I can get to it just to press the reset button. Thanks, another great video.

@AndreasSpiess 4 жыл бұрын

I think such a part could solve your problem.

@brainfornothing 4 жыл бұрын

Thanks for sharing and stay safe !

@AndreasSpiess 4 жыл бұрын

I try!

@buzhug35 4 жыл бұрын

Very usefull as usual. Thanks a lot and best regards.

@AndreasSpiess 4 жыл бұрын

You are welcome!

@electronic7979 4 жыл бұрын

Helpful video 👍

@AndreasSpiess 4 жыл бұрын

Thank you!

@TheEmbeddedHobbyist 4 жыл бұрын

This is OK for simple embedded uP, but if there is any storage requirements in the system then it does not fully remove the problem. The Raspberry PI would still crash and not recover if you just hit the reset, if it's writing to the memory card at that point game over. re-install of memory card might be required. So if there is a memory storage of important information required we need to add a little bit extra. Capacitors to hold up the supply and a diode to stop the falling incoming power discharging the caps. the voltage detector instead of hitting the reset should be connected to a non-maskable interrupt, So the controller has time to do a bit of house keeping, save data to non-volatile memory, etc, and go into a safe state ready for power down. Quite a few uP have the reset driven from the clock oscillator, the clock has to run for a number of cycles before the reset is released, making sure that there is a stable clock running before your code is let lose. When you have to design of power glitch's there are other issues involved, Hot or COLD starts. do you want to load defaults in to system (cold start) or do you want to reload the settings last set while running (HOT start), so the need to save settings as power is lost, because if power is only removed for 100ms or so , you don't want the usre to have reset all the controls back to where they had set them. Still a great video if you read all the way down to here. :)

@AndreasSpiess 4 жыл бұрын

Concerning the protection of the RPI: I showed how it can be done at the end of the video (GPIO3, Super Caps)

@bobbonham4823 4 жыл бұрын

Thanks. Once again, something I can use.

@AndreasSpiess 4 жыл бұрын

You are welcome!

@richard_wenner 4 жыл бұрын

Comprehensive description and demonstration.

@AndreasSpiess 4 жыл бұрын

Thank you! I am still watching your (epic) video.. My wife easily can watch a whole Netflix series during he same time ;-) It seems you had a great time.

@richard_wenner 4 жыл бұрын

@@AndreasSpiess HA! Yes it was a good 21st birthday for her. I hated the ice hotel but the Northern Lights made up for everything.

@simfungreek 4 жыл бұрын

Great educative video.

@AndreasSpiess 4 жыл бұрын

Thank you!

@langrock74 4 жыл бұрын

Another awesome video. Danke!

@AndreasSpiess 4 жыл бұрын

Bitte, gern geschehen!

@CristiIstrate 4 жыл бұрын

Exactly what I needed!

@AndreasSpiess 4 жыл бұрын

:-)

@user6193 3 жыл бұрын

Very helpful video for me as it help me to get the idea to solve the problem in flight controller for a mini quad powered with 1s 3.7volt lipo where it got discharged below 3volt if I continue to fly the quad for some more time after low battery indication (a small camera connected with battery will keep on consume current even after landing the drone)... by using this small component i can protect my lipo by cutting the supply if Vbat < 3volt. Thanks for this informative video as always :)

@albygnigni 4 жыл бұрын

thanks andreas for this video! very informative as always! As many other viewers have suggested, most modern MCUs, even smallest ones (e.g. ATTiny), have brownout detection capabilities. In another way, also the raspberry pi has undervoltage detection capabilities (the "yellow lightning bolt") and you can write a script that powers it off. As for new designed boards, I suggest to use single PMICs that have all those function built-in. Otherwise, selecting a LDO or a Battery IC with a V_OK pin could be another solution.

@AndreasSpiess 4 жыл бұрын

What PMIC would you use for a 3.3 volts project? And what LDO? This couls be interesting for other viewers, too.

@albygnigni 4 жыл бұрын

@@AndreasSpiess From Texas Instruments: - TPS3702 Supervisor IC has capability for UV and OV monitoring - TPS778 LDO has a power-good output - As for integrated solutions, the BQ25570 you showed in video #278 has all those capabilities but is not so cheap By the way, TI, Analog, ST and many more companies are making these kinds of ICs, but they are using really small and often BGA packages, so it is difficult for a maker to use them in prototyping. Those ICs are also application-specific and not general purpose, so I suggest to take a look at the catalogs.

@AndreasSpiess 4 жыл бұрын

Thanks for the part numbers. The ones I saw were also for smaller voltages...

@BorisDessimond 4 жыл бұрын

@@albygnigni Unfortunately not found on aliexpress for 2-3$ 10-20pcs like other parts :( Thanks for the tips !

@albygnigni 4 жыл бұрын

@@BorisDessimond You can try to look at LCSC, I have found the TPS3705-33 that is similar to the TPS3702 and it is 0.45€/piece , while the LDO can be found in the adj version (TPS77801D) for 3.82€/piece

@Olavotemrazaodenovo 4 жыл бұрын

Congratulations from Brazil.

@saugatsigdel7381 4 жыл бұрын

Hello sir, I love to learn from your channel and I haven't missed a single video from you. You have addressed the really critical issue for professional product development. As a beginner, I want to know all the essential kinds of stuff like this (the critical one that most of the hobbyist miss). Please suggest me some books or any resources that teach me these kinds of stuff.

@AndreasSpiess 4 жыл бұрын

There are not a lot of books for this modern stuff. I showed my only books I have in other videos.

@saugatsigdel7381 4 жыл бұрын

@@AndreasSpiess it would be a great help for me if you can please post the link for the video describing books or post the name of the book in comment.. Sir..

@ep_dimi 4 жыл бұрын

thanks once again for the info!

@AndreasSpiess 4 жыл бұрын

Any time!

@prathambumb5593 4 жыл бұрын

Really Helpful 👍 Thanks

@AndreasSpiess 4 жыл бұрын

You are welcome!

@adamdms 4 жыл бұрын

Great episode! I didn't know.

@AndreasSpiess 4 жыл бұрын

Thank you!

@mvadu 4 жыл бұрын

RapsberryPi uses an internal power management chip (PMIC, MxL7704 in Pi 3&4) has some of these power management built in. BMC Chip actually works at ~1V range, and it does boot up and it has a section during bootup where it detects if the voltage is enough to continue boot process. During the operation is you draw too much power, and supply voltage dipped below 4.63V is tags is and you can examine it using vcgencmd get_throttled command.

@AndreasSpiess 4 жыл бұрын

I think I mentioned it. But still you need to shut it properly down

@bobpaydar 4 жыл бұрын

you are wonderful, thanks

@jamess1787 4 жыл бұрын

Love this video. Thanks Mr.SwissGuy =) [aka Andreas!]

@AndreasSpiess 4 жыл бұрын

Thank you!

@Graham_Wideman 4 жыл бұрын

Andreas: Nice video on a useful and perhaps lesser-known part. A minor point -- in your schematics the battery symbol is upside down. The long bar represents positive in the standard symbol.

@AndreasSpiess 4 жыл бұрын

You are right.

@wilyfreddie 4 жыл бұрын

Thank you very much for this video! Will immediately add this to our solar power system. Can I use any resistor for the KA75330 circuit?

@AndreasSpiess 4 жыл бұрын

More or less. I uses 22k

@Firejaps 4 жыл бұрын

Thanks, dear Andreas 🇧🇷

@AndreasSpiess 4 жыл бұрын

You are welcome!

@minepro1206 4 жыл бұрын

Wow, I couldn't have imagined that a capacitor in Vcc was the culprit to one of my projects. 👍

@AndreasSpiess 4 жыл бұрын

:-)

@ugetridofit 4 жыл бұрын

Just as a FYI. The ESP32 has a setting in menuconfig where you can select its reset detect level. Arduino people don't know this because Arduino does not allow access to the many, many options in the ESP32 menconfig system.

@AndreasSpiess 4 жыл бұрын

I tried it in the Arduino IDE, but I was not able to chage the brounout level. And it works only, if theMCU runs, as I showed in the video :-(

@si98justme1 4 жыл бұрын

I went into this video thinking he was referring to Voltage Regulators, but due to a language/interpretation issue was calling them Supervisors, and that I wasn't going to learn much if anything... Whoops my bad, and I learned two things to add insult to my hubris: I'm not as smart as I thought I was, and learned about a part, that even as a professional (many years ago), I didn't know about.

@abhijitborah 4 жыл бұрын

This Swiss' videos are always perfectly researched. And satisfying to learn from.

@whitefields5595 4 жыл бұрын

@@abhijitborah He's Swiss .....

@abhijitborah 4 жыл бұрын

@@whitefields5595 Seeking a thousand pardons. My bad. Thanks, edited it out.

@Kevin192291 4 жыл бұрын

Thank you so much, you are the man.

@AndreasSpiess 4 жыл бұрын

:-)

@ManishMoorjmalani 2 жыл бұрын

thank you so much

@AndreasSpiess 2 жыл бұрын

You are welcome!

@marcrives279 4 жыл бұрын

You should definitely make a part 2, digging further on Power on Reset (POR) and Brown Out Detection (BOD). The whole point of a MCU is to have all those components integrated *and* to make use of them. Using an external supervisor is only for very specific cases.

@AndreasSpiess 4 жыл бұрын

I looked into the brownout detector of the ESP32. It works if you reduce the voltage from 3.3 volts. But I did not find a way to reset the MCU down after this message. The brownout message did not shut the CPU down. And it is not very well documented...

@ashishsunny1916 3 жыл бұрын

Thanks a lot

@AndreasSpiess 3 жыл бұрын

You are welcome!

@uvatham 4 жыл бұрын

Useful component

@AndreasSpiess 4 жыл бұрын

:-)

@mrmarkom 4 жыл бұрын

Hi Andreas, Njce video. I guess this is handling levels below what can be done with Brown out detection, which is present in many MCUs. I did some work with ATmega and configured BOD to be able to be stable on quite a low voltages.

@AndreasSpiess 4 жыл бұрын

The ESP32 also has a BOD. Biut it only worked if hte processor still worked. So no protection if you come from below the threshold. And it seems yo ucan fool the Atmega 328, too (kzfaq.info/get/bejne/bLaWZtOKmK3ccoE.html )

@jawolllinger 4 жыл бұрын

Hi Andreas, thanks for the awesome video. As I'm still quite new to making my individual electronics projects so your videos help me quite a lot. I have a question regarding the supercapacitors for using with the KA75450 as a safe shutdown system for the raspberry Pi: In your video #133 you suggested 15-20 F supercaps to have enough time for the Pi to safely shut down. That video was before the Pi4 and I was wondering whether the 15-20F recommendation still applies with the Pi4's power consumption? Thanks in advance.

@AndreasSpiess 4 жыл бұрын

You have to try. I do not know. I assume the Pi for will also shutdown faster.

@PhG1961 4 жыл бұрын

Excellent Sunday morning entertainment.

@AndreasSpiess 4 жыл бұрын

Thank you!

@zyroxiot9417 Жыл бұрын

thanks by the infos.

@AndreasSpiess Жыл бұрын

You are welcome!

@nigeljohnson9820 4 жыл бұрын

The first voltage supervisor I used was the TL7705, this had a problem that it released the reset when its own supply voltage is low. When my company switched from the NMOS to the CMOS 8085, the processor continued to operate below the supply voltage at which the reset circuit stopped working. The result was that the processor would restart (leave reset) during the time it was being switched off. It is worth checking that the reset signal is maintained until the processor is safely off. Ideally the reset signal should be maintained all the way down to zero supply volts, One solution to this problem is make the reset a passive resistor pull down signal and "NOT in reset" active high.

@AndreasSpiess 4 жыл бұрын

You are right. I showed that the three switch on again at around 0.7 volts. Which should be ok for a 3.3 volt MCU.

@pulesjet 4 жыл бұрын

I have a number of LiIon battery projects these would be handy for. Preventing Over charge and or Over Discharge situations. Been using the LM393 and resistor divider. This would be much easier I think. 3.3v version is just about ideal for the task on LiIon cells and with a added resistor would work for the LeFePo4 type. Just ordered 10 to mess with. Thank You. China is having some rather serious issues with the virus thing . Orders are taking quite a bit longer then the normal long times in the past. Guessing this one will take two months to show up.

@AndreasSpiess 4 жыл бұрын

Overvoltage protection is often built-in into the charging chips.

@PanosKontogiannis 4 жыл бұрын

Thanks, Great video. What about the TL7702 series. I use it on sensitive applications but never tested if they actually perform. I took the word of Texas instruments for granted

@AndreasSpiess 4 жыл бұрын

They seem to be a little more sophisicated chips. But with a similar purpose.

@kwazar6725 4 жыл бұрын

You need a batt ups with pi as they corrupt fat sdcards easily. This is a cool/geil way to monitor voltages and shutdown and on safely. Thanks andreas!👍

@AndreasSpiess 4 жыл бұрын

This is particularly true if you add a few super caps or a small battery as shown at the end of the video.

@fullpower8382 2 жыл бұрын

Oh man wie konnte mir der coole Kanal so lange Zeit verborgen bleiben?!?! Saubere Arbeit! Gleich abonniert weil geiler shit!!

@AndreasSpiess 2 жыл бұрын

Willkommen and Bord! Du hast ja noch etwas aufzuholen wenn du willst ;-)

@fullpower8382 2 жыл бұрын

@@AndreasSpiess Hi Andreas, vielen Dank, ich bin schon fleissig dabei deine Videos zu schauen, da werde ich definitiv eine Weile beschaftigt sein, aber der Wille ist ungebrochen! ;-) Wäre schön Leute aus der gleichen Gegend zu treffen die ebefalls an dem Thema interessiert sind. Hast du da vielleicht ne Idee?

@AndreasSpiess 2 жыл бұрын

@@fullpower8382 Es gibt in verschiedenen Städten Gruppen rund um TTN.. Die sollten auf der TTN Homepage gelistet sein.

@ralfhesterberg3346 4 жыл бұрын

For the Esp32 you need to configure your brownout detection voltage: docs.espressif.com/projects/esp-idf/en/latest/api-reference/kconfig.html#config-esp32-brownout-detox then you not need any external voltage supervisors.

@davefiddes 4 жыл бұрын

The brownout detector is useful but doesn't cover all possible failure scenarios as Andreas shows in the video. This is why Espressif have the additional recommendation to include an external supervisor.

@AndreasSpiess 4 жыл бұрын

@Ralf: I tried to change the BOD threashold voltage as well as the alarm in Arduino IDE. I only was capable to switch BOD off, but not more :-( I would be glad if you have more info. And BOD only worked if the CPU still worked. So no protection against "gibbersh" and Flash error.

@browaruspierogus2182 4 жыл бұрын

Exactly. For such low currents and voltages no need for some supervisor complicating the project. Even decent Zener diode will do here Besides you can power your esp with small power bank that has all the protections you need

@NikolaiVarankine 2 жыл бұрын

@@browaruspierogus2182 I tend to think ESP and others are targeted to button cell power primarily as they all fight for the less consumed power as possible.

@andrewtitcombe8378 Жыл бұрын

Good explanation . So i am using the KA75330 with an esp32 Epaper to wake when the battery gets to low. to display a low battery warning and then putting the esp to sleep only to be wake when the KA75330 signal goes high to clear the low voltage warning. As one of the big issues with epaper is if the battery goes flat.Iit just sits there displaying the last thing displayed, and the user has no idea that it is not functioning or updating. It would be useful for esp32 e-paper such as LILYGO® TTGO T5 V2.3.1_2.13 Inch E-Paper added a battery monitor chip to the board as standard.

@AndreasSpiess Жыл бұрын

Good point! And a good implementation of a solution.

@meteor8076 4 жыл бұрын

very interesting

@AndreasSpiess 4 жыл бұрын

:-)

@RobinGerritsen1995 3 жыл бұрын

Thanks for the heads-up! Got some nasty problems with undervoltage. I can't find a voltage detector for >4v threshold with to-92 footprint on AliExpress. I am currently working with the wemos development boards and had some problems with undervoltage. Now I want to keep the reset pulled to GND untill the 5V supply voltage is above 4V.

@AndreasSpiess 3 жыл бұрын

I use the ka75450 for 4.5 volts. It does not come in a TO-92. This is a very old case.

@ammarsyaf3035 4 жыл бұрын

this video has reveal the mystery I faced when working with power hungry gsm module

@AndreasSpiess 4 жыл бұрын

Then maybe a large capacitor is a better idea to prevent such situations ;-)

@shakerileiwat4341 4 жыл бұрын

Amazing ♥♥♥

@AndreasSpiess 4 жыл бұрын

Thank you!

@fingerprint8479 4 жыл бұрын

Interesting and useful. It is a perfect addition to my battery powered project. One question: on 12:30 minutes on your video you show a diagram of a circuit to shut down not only the ESP32 but also all peripherals when the battery is under 3.3v but show no values for the resistors. How can I calculate the resistors for the circuit? Thanks again.

@AndreasSpiess 4 жыл бұрын

You do not need to do any calculations. Just pick two (If I remember I used 22k). But they do not matter too much.

@jamest.5001 4 жыл бұрын

Interesting!

@AndreasSpiess 4 жыл бұрын

:-)

@christopherguy1217 4 жыл бұрын

Why doesn't the Raspberry Pi have this as part of its board? Would save many a SD card from getting corrupted. Great video, I'll need to get some of these parts and start incorporating them with my boards.

@AndreasSpiess 4 жыл бұрын

Ihe Pi4 seems to have one. But because the Raspberries have an operationg system you have to shut them down, not just switch them off. This is the reason for my proposal at the end of the video.

@roidroid 4 жыл бұрын

IIRC you can power 3.3V MCUs like the ESPs by simply using a LiFePO4 cell (w' it's protection-&-charging circuitry) *without any voltage regulator.* You may have even already had a video about this, i forget. The cell won't get charged above 3.6V, and the protection circuit will probably kick-in and cut off the battery when it gets down to around --2.5V. So you'll never get outof the ESP's voltage range.-- _Edit: LiFePO4 protection circuits cut it off at 2.1V, so it may still be a problem on the low end._

@AndreasSpiess 4 жыл бұрын

Changing the battery technology is not a solution.But if your battery has a low voltage protection, you do not need this part.