If frequency vs vcc curve is linear, that means if I run my arduino on rectified mains it will have 3ghz and I can use it as a cpu instead of the Intel I have now
1:52 I had to look up the term munging. Intuitively I felt it was an electronic form of mashing. According to Wikipedia: Mung or munge is computer jargon for a series of potentially destructive or irrevocable changes to a piece of data or a file. It is sometimes used for vague data transformation steps that are not yet clear to the speaker. Common munging operations include removing punctuation or html tags, data parsing, filtering, and transformation. The term was coined in 1958 in the Tech Model Railroad Club at the Massachusetts Institute of Technology. In 1960 the backronym "Mash Until No Good" was created to describe Mung, and a while after it was revised to "Mung Until No Good", making it one of the first recursive acronyms. It lived on as a recursive command in the editing language TECO. Usages of the term appear in munged password (a strong, secure password created through character substitution), data munging (cleaning data from one "raw" form into a structured, purged one) and address munging (disguising an e-mail address). Munging may also describe the constructive operation of tying together systems and interfaces that were not specifically designed to interoperate. Munging can also describe the processing or filtering of raw data into another form. As the "no good" part of the acronym implies, munging often involves irrevocable destruction of data. Hence in the early text-adventure game Zork, also known as Dungeon, the user could mung an object and thereby destroy it, making it impossible to finish the game if the object was an important item.
There are two kinds or regulators for 3.3 and 5v. One are 150mA delivery draw. The others are 500mA. So chose wizely, but what makes the difference is that those 150mA regulators have Low quiescent current. means if you want to put arduino to sleep it will draw very little current. unlike the 500mA regulator which even if you put arduino to sleep it will draw atleast 10mA in some occasions. chose wisely depending on your application.
KB33 - 150mA max output but low current draw. KB50 or KBAA (adjustable) are also 150mA. It helps when your making a battery electronic. or even car accessory that will always be connected.
there's yet another 328p in a board that is slightly larger, with with VCC and GND slots next to each digital and analog pin. For example, when you want to connect a potentiometer to an analog pin, the VCC and Gnd are just next to it. From a personal perspective, i really like the aesthetics of these boards, I feel like turning the soldering iron ON and put something together every time I see one.
Yeah, I think it's this one: Atmega328 Board 5V 14 Pins Pincompatible For Arduino Pro Mini New #UnbrandedGeneric www.ebay.com/itm/Atmega328-Board-5V-14-Pins-Pincompatible-For-Arduino-Pro-Mini-New-/401171901022
I purchased several versions of the Arduino Promini 3.3v to create a low power Arduino piece. But outside could not distinguish whether this is 3.3v or 5v. I found information on the Internet that I can see the letters and numbers written on the generator. By watching your video, I was able to better understand the utility value of 3.3v. Thank you.
Julian, why are you using pencil as a pointer? It seems too risky as you may eventually create shortcut by touching contact with carbon tip, which is conductor.
I have some and the serial pins are reversed. It looks like the one you show at around 5:35 is like that? I have been chasing a problem with a clock that I made with rtc. Nothing has changed and now it is not working for other clocks I have made? Driving me nuts : )
I had a strange incident I bought Pro Mini - ATMega328, 5v-16 Mhz version. I just realized that the project I was working on was using a TTL 3.3v device (for example: ESP8266). In simple terms, I had to use a level shifter to change the TTL 5v Pro Mini to 3.3v, but I didn't want to because it wasted energy, money and space. Then I was fun, changing the power supply voltage of the VCC Pro Mini from 5v to 3.3v. And surprise! no problems at all when running the program! The TTL on my Pro Mini automatically changes to 3.3volt, so I don't need to use a level shifter. Conclusion: There are several Pro Mini versions of 5volt 16Mhz that are flexible, can be changed to a 3.3volt 8Mhz version simply by changing the VCC Voltage
LostName I just find the Digispark convenient because it has all the regulators, caps and protection diodes integrated on a board already. Plus it does some simple USB stuff and can be programmed without an ISP. But yes of course rolling your own bare system is optimal.
Brilliant video, I have been using 5v pro minis with the voltage regulator removed, with an 18650 cell. My question is , if I set the pro mini to 8mhz but it still has a 16mhz resonator will it work at 3v?
hi, i've just started using arduino too and would like to miniaturise my projects. Would love it if you could document your whole process of assembling the mini version
I have a 5v Pro Mini from my local Micro Center (an American electronics store), and the resonator appears to say A.x as well! I wonder why they are marked the same, or if the resonators are from the same manufacturer.
Alice has a whole bunch of Pro Minis listed (including one with a Crystal) - www.ebay.com/sch/m.html?_odkw=&_ssn=alice1101983&_osacat=0&_from=R40&_trksid=p2046732.m570.l1313.TR12.TRC2.A0.H0.Xpro+mini.TRS0&_nkw=pro+mini&_sacat=0
It may be running at less than 3.3V (although the Si7021 is happy down to 1.9V) and since communication is digital (I2C) the sensor readings won't be affected.
Oh yes, they don't hide much :D The resonators on mine seems to be crystal, not a ceramic one. It takes up more space on the tiny board than the microcontroller itself.. Just a guess, but by the size it's more than likely (it's also the only through-hole component on the entire board, not taking the pinouts into account).
Hi Julian Would the low voltage to the hygrometer chip because of 2 regulators in series have caused the difference in humidity between the other 2 meters you had in the previous video. You had been quite surprised by the difference.
Most of my Arduinos are from Robotdyn and they come in a Strip(when you buy more than 1) with labels on it and on the back is a list and every Arduino is marked with a pen.
There doesn't appear to be a limit on how quickly you can read the sensor. There is data on how quickly the sensor will respond to changes in RH assuming a 1m/s airflow rate.
Julian Ilett, There are 2 parameters of timing to take into consideration: 1. The conversion time of both temp and humidity dependent on resolution. 2. Response time. A delay between readings would be beneficial.
Hi Julian, When I want to identify a component and I can't read the markings, sometimes viewing them at an angle, let's say 40 degrees, makes it so much easier to read them :)
If clock frequency doesn't have to be exact or temperature critical, you can use the internal PLL and the factory calibrated RC clock. I do it all the time. Then you can set the frequency to whatever you want. I've run 1MHz plus sleep for low power and 20 MHz for time critical applications.
Sounds odd but I've never used the IDE. Old school. I struggled with coming up with a working Make file and that is where the fuses get set but it may be possible to set clock speed on the fly. I have set some aspect of clock speed on the fly in init code and looped until clock status is stable to exit and continue.
See, that's why I always program AVRs via ISP, be it from the Arduino IDE or in any other way. I often get annoyed, how slow the Arduino abstraction makes everything and end up writing all the registers myself instead of using Arduino functions. As far as I know you can only change the fuses via ISP, so you need an ISP programmer anyway (usbasp for 3$ or so).
Ah, I forgot about the Arduino's boot loader. I usually end up trashing it. You can either make your own ISP or buy one off of Ebay for cheap. I found it fun to program the ATtiny and by default they are set to 1MHz so it would be common to change the fuse settings when more speed is needed. Amazing what you can do with a buck and some change and the open source cross compiler. Everyone familiar with AVRDUDE?
20 MHz is within safe operating area, so I'd say not. Only if you go higher than that, which I've heard some people do. Standard Arduino library doesn't support 20 MHz, your delay()s, milli()s, and micro()s will be off. In most cases you'd better optimize your code instead, or switch to a faster micro. A Chinese company makes an ATmega328P-compatible MCU called LGT8F328P, that runs at up to 32 MHz. There are cheap boards available. I've heard both good and bad things about them.
All the Arduino Pro mini that I've bought in the last 3 years are all red reset button = 3.3V, black or silver = 5V. Wonder why, I'm talking about at least 60 pieces from about 5 different suppliers.
Yeah. For projects that are actually just programmed and not monitored by a computer using serial this isn't necessary. I recently made a device that measures voltage of a LiPo with a voltage divider + 0.26v since this isn't that accurate and it's about the ratio. I am using an OLED i2c to display it. It also shows the uptime using millis() and battery percentage if full means 4.2 v. Love the channel btw.
I hope you will be identifying your USB/serial converter for us, with pinouts etc. I bought a handful of these Pro Minis but got the wrong converter/programmer. In the back of my head you have a video where you present a few of these, but I couldn't find it.
Julian Ilett yes it's smaller but what about when you add headers. It makes it a tad awkward in size. Do you remove them or have some sort of pogo pin setup.
***** Why? Nanos work very well. I especially like the screw terminal breakout for them, it makes it great for putting them into control environments. Plus the Nano is about $3. What does the micro do that the Nano doesn't?
It would probably oscillate OK, but timings for delay() and millis() would be inaccurate. As far as I know, Arduino only understands 8MHz and 16MHz clock sources, so you may have problems getting these timings right, even after altering the 'boards' file.
I saw weird Arduinos on ebay today, variously being called pro micro and pro mini but theyre not like Arduinos Ive seen before. they have the atmega32u4 but idk if theyre china versions of actual Arduino boards I wasnt familiar with or parts bin knock ups or what. item 291547273695 looks like a pro mini with all the small components shoved down one end, and items 191928750938 and 191981130271 might be the same thing with a slightly different layout, but one of them claims to be 5V 8MHz which is kind of odd. and the other has leonardo in the listing title but I thought the small form factor version of the leonardo was the micro which looks like a nano but longer and that isnt one of them. its very confusing but theyre dirt cheap so maybe I'll get a couple to have a look at
The first one is a pro mini but has two rows of pins at one end - not certain about this, but I think this provides access to the ICSP pins so you can re-burn the bootloader. The other two are pro micros (not Arduino micro) which have the ATmega32U4 chip (with integral USB hardware) and a USB socket on board.
The "pro mini" with the ISP pins on the end are the ones I prefer. I essentially buy them because they are an AVR+crystal+regulator+easy to access pins, not because the are an Arduino. I always get rid of the Arduino bootloader anyway and program them via ISP. In most projects the serial-to-USB of a nano isn't needed once done, so it would be a waste of space. Since I solder in (onto another PCB) the whole pro mini board in some projects, it's useful to have easy access to the programming pins and not have to lay them out yourself.
You need to determine what voltage your version operates on. The lower voltage (3.3v is 8 Mhz) the lower the clock speed (CPU). You can still do much with the lower clock speed. The same code would run on both units... So you can make the l.e.d. blink any rate you want all in the code. Julian has a great video in which he examines the "Arduino" speeds compared to native Atmels (programmed w/ ASM or C?) with AVR I think.. Very Interesting indeed! Best Regards. -Leap
Yea the same code runs on both but it won't run at the correct speed if the right speed isn't selected in the IDE. Voltage doesn't matter unless something is hooked up. On a 3.3V board when the serial converter is connected you can input 5V on the VCC pin and it bypasses the regulator, it only uses the regulator when you connected power to the RAW pin.
Recently got an arduino to play around with, but while trying to find some resources to learn about programming I was absolutely overwhelmed with information about robots and other stuff I'm not immediately interested in. Does anyone have any suggestions as to good(!) resources for starting with arduino in projects like Julian does? There's just so much information on the web that I can't see the trees for the forest...
The best thing about the internet is all the free stuff and the worst thing about the internet is all the free stuff! I recommend Exploring Arduino by Jeremy Blum which is an excellent book full of electronic circuits and code examples that are fully explained. Also look for any titles by Simon Monk. There are loads of good websites with free information on them but there is a lot of dross also. The books I mention are well written and reliably accurate.
yeah there are some pro minis that fit those huge hc-49 crystals on them: de.aliexpress.com/item/ProMini-ATmega328P-5V-Compatible-for-Arduino-Pro-Mini/32525859745.html
I'm amazed that none of your pro minis have a crystal. Mine does and it says YC16000M. With a tiny regulator LO5 (or LG5?). And the pins are from every side of the board, yours are mostly from three sides only. Interesting how they're inovating even those devices. Some Pro Minis out there have the tiny chip and massive crystal, some have tiny resonator and large (comparatively) chip. It's just all a bit funny.
Hi Julien, All my 9 ProMinis have either the KB50 or the L05 as 5V regulator. 4 of them came with ceramics marked AT and AQ (just like yours) and the other 5 actually have a full size crystal on board marked 16.000. apparently I don't have any 3V3 ones. Cheers! That's my collection: imgur.com/ghoVNcH
The extra module also provides level-shifting on the I2C pins, not just a 3.3V step-down on the power! It wasn't needed as those level-shifting components were present on the sensor board but it would be necessary if you were to interface a 3.3v sensor board that doesn't contain level-shifting to a standard 5V arduino uno, nano or pro mini.
You wouldn't need a level shifter for the signal even when hooking up a 5V Arduino to a 3.3V sensor. Just make sure you don't put out 5V on the I2C pins and use external pullups to 3.3V (you would need the external pullups anyway). An AVR running at 5V "understands" 3.3V as logic high.
it would have been much better if you had spent 10 minutes beforehand making some notes so that it sounded like you knew what you were talking about instead of rambling about.
If frequency vs vcc curve is linear, that means if I run my arduino on rectified mains it will have 3ghz and I can use it as a cpu instead of the Intel I have now
Try it :)
It will very rapidly do something, I suspect it won't be rapidly processing any data though ;)
Try it! But, keep it in hand.
A three-year-old joke and it's still funny Haha
Always like your channel ,I learn new stuff without realizing I`m being educated
Thanks for making it fun and painless
Put 9 volts on Raw and measure VCC. 3.3v = 8 Mhz 5v = 16 Mhz. That should work.
Neat trick :)
Haha that's exactly what I was thinking! 😂😂😂
smart!
Be careful, some of the 3.3v LDO regulators can only handle 6v in.
Thank you I just made sure that mine are 3.3V using your method!
At 7:00, the smd resistors are from the E96 series. The number is assigned to a standard value, the letter is representing a multiplier.
And I thought 4-band resistors were trouble enough!
I hope to see more of the arduino videos. I need to learn all I can. as of now I'm clueless when it comes to programming. I really enjoy your videos.
Thanks James :)
Well done Julian , you have educated me on Pro Mini and Power regulator, good Video Mate.
1:52 I had to look up the term munging.
Intuitively I felt it was an electronic form of mashing.
According to Wikipedia:
Mung or munge is computer jargon for a series of potentially destructive or irrevocable changes to a piece of data or a file. It is sometimes used for vague data transformation steps that are not yet clear to the speaker. Common munging operations include removing punctuation or html tags, data parsing, filtering, and transformation.
The term was coined in 1958 in the Tech Model Railroad Club at the Massachusetts Institute of Technology. In 1960 the backronym "Mash Until No Good" was created to describe Mung, and a while after it was revised to "Mung Until No Good", making it one of the first recursive acronyms. It lived on as a recursive command in the editing language TECO.
Usages of the term appear in munged password (a strong, secure password created through character substitution), data munging (cleaning data from one "raw" form into a structured, purged one) and address munging (disguising an e-mail address).
Munging may also describe the constructive operation of tying together systems and interfaces that were not specifically designed to interoperate. Munging can also describe the processing or filtering of raw data into another form.
As the "no good" part of the acronym implies, munging often involves irrevocable destruction of data. Hence in the early text-adventure game Zork, also known as Dungeon, the user could mung an object and thereby destroy it, making it impossible to finish the game if the object was an important item.
Yeah, I looked that up a couple of days ago - not much mention of hardware munging - but I guess it applies in much the same way.
I was just looking for SMD codes tonight and came across this. thought it might help great video
caxapa.ru/thumbs/588912/smd-codes.pdf
forgot to paste the link sorry
There are two kinds or regulators for 3.3 and 5v. One are 150mA delivery draw. The others are 500mA. So chose wizely, but what makes the difference is that those 150mA regulators have Low quiescent current. means if you want to put arduino to sleep it will draw very little current. unlike the 500mA regulator which even if you put arduino to sleep it will draw atleast 10mA in some occasions. chose wisely depending on your application.
Thanks for that - wise words. An even better reason to properly identify the on-board regulator.
KB33 - 150mA max output but low current draw. KB50 or KBAA (adjustable) are also 150mA. It helps when your making a battery electronic. or even car accessory that will always be connected.
Thank you for that Info, just bought some 150mA , Cool
Cant you just put 7V on the Vin Pin and measure the voltage comming out of the regulator?
Of course that's the other way to identify the 3.3V ones!
The good ones will liberate their magic smoke!
Not really, they all have a Voltage regulator on the board ;)
Depending on the LDO, you may not want to put more than 5V on a 3.3V regulator that size ;)
Great video. Love watching your videos all the way from New Zealand! Chur bro
9B27. Just for fun. How many 9s go into 27 and how many of the answer go into 9? Great video my good friend.
Thanks Raymond :)
Your very welcome my friend.
there's yet another 328p in a board that is slightly larger, with with VCC and GND slots next to each digital and analog pin. For example, when you want to connect a potentiometer to an analog pin, the VCC and Gnd are just next to it. From a personal perspective, i really like the aesthetics of these boards, I feel like turning the soldering iron ON and put something together every time I see one.
Yeah, I think it's this one: Atmega328 Board 5V 14 Pins Pincompatible For Arduino Pro Mini New #UnbrandedGeneric www.ebay.com/itm/Atmega328-Board-5V-14-Pins-Pincompatible-For-Arduino-Pro-Mini-New-/401171901022
Julian Ilett Yes, that's the one i was referring too. Thank you, I didnt know how to search for this particular board setup.
My resonator appears to say "AC".
Perhaps it uses bipolar alternating watts?
That sounds familiar.. Is it something bigclive said?
Dennis W What? It's an entire concept in electronics....
+Dennis W
Big Clive would say "I'm not really sure". And everyone gets a bit drunker.
Ur joking, right?
***** No, google it. You're so uneducated about electronics.
Hi Julian,
the two versions of the Mini Pro that I have are for 5V. The regulators are marked KB50 and the resonators are AT.
Regards, Udo, dk3bi
Cheers - they fit the same pattern :)
I purchased several versions of the Arduino Promini 3.3v to create a low power Arduino piece. But outside could not distinguish whether this is 3.3v or 5v. I found information on the Internet that I can see the letters and numbers written on the generator. By watching your video, I was able to better understand the utility value of 3.3v. Thank you.
Julian, why are you using pencil as a pointer? It seems too risky as you may eventually create shortcut by touching contact with carbon tip, which is conductor.
I have some and the serial pins are reversed. It looks like the one you show at around 5:35 is like that? I have been chasing a problem with a clock that I made with rtc. Nothing has changed and now it is not working for other clocks I have made? Driving me nuts : )
I had a strange incident
I bought Pro Mini - ATMega328, 5v-16 Mhz version.
I just realized that the project I was working on was using a TTL 3.3v device (for example: ESP8266).
In simple terms, I had to use a level shifter to change the TTL 5v Pro Mini to 3.3v, but I didn't want to because it wasted energy, money and space.
Then I was fun, changing the power supply voltage of the VCC Pro Mini from 5v to 3.3v. And surprise! no problems at all when running the program!
The TTL on my Pro Mini automatically changes to 3.3volt, so I don't need to use a level shifter.
Conclusion: There are several Pro Mini versions of 5volt 16Mhz that are flexible, can be changed to a 3.3volt 8Mhz version simply by changing the VCC Voltage
I have a nice box of mixed minis and nanos, and UNOs and megas.
If you really want to go small, consider the Digispark which is absolutely tiny. It has an ATTiny85 and I believe it does hardware I2C.
kfishy or just go with a normal attiny - that way you are not locked in by the digispark bootloader and it's weird clock rates for USB
LostName I just find the Digispark convenient because it has all the regulators, caps and protection diodes integrated on a board already. Plus it does some simple USB stuff and can be programmed without an ISP. But yes of course rolling your own bare system is optimal.
kfishy its 5v only tho
The other advantage of the digispark boards, is that you can buy Chinese clones for £0.82 from Aliexpress...which is practically free.
Did you ever find out if your sensor was accurate?
Good stuff. Worth watching .
Brilliant video, I have been using 5v pro minis with the voltage regulator removed, with an 18650 cell.
My question is , if I set the pro mini to 8mhz but it still has a 16mhz resonator will it work at 3v?
hi, i've just started using arduino too and would like to miniaturise my projects. Would love it if you could document your whole process of assembling the mini version
Helpful, as always. Thank You
I have a 5v Pro Mini from my local Micro Center (an American electronics store), and the resonator appears to say A.x as well! I wonder why they are marked the same, or if the resonators are from the same manufacturer.
Would be good if you could supply links to suppliers of the various boards you featured.
That's pretty much impossible - they were all bought some time ago.
Maybe some suggestions of you favourite suppliers - I assume they are mostly from Ebay?
Alice has a whole bunch of Pro Minis listed (including one with a Crystal) - www.ebay.com/sch/m.html?_odkw=&_ssn=alice1101983&_osacat=0&_from=R40&_trksid=p2046732.m570.l1313.TR12.TRC2.A0.H0.Xpro+mini.TRS0&_nkw=pro+mini&_sacat=0
Quite a few of them have crystals too!
That's great - thank you.
So have you been under powering the humidity sensor with the extra board?
It may be running at less than 3.3V (although the Si7021 is happy down to 1.9V) and since communication is digital (I2C) the sensor readings won't be affected.
Very informative & useful, thanks!
Is 3.3 8mhz is better than that 5v 16mhz ? Which one cost higher 3v3 or 5 v ????? , Plz tell about performance difference between both of these !!
I have 2 Pro Minis, they both have resonators marked JY16.000M1E and regulators marked L05.
Both are of course 16 MHz/5V ones.
Cool, thanks. They're easy to identify :)
Oh yes, they don't hide much :D
The resonators on mine seems to be crystal, not a ceramic one. It takes up more space on the tiny board than the microcontroller itself.. Just a guess, but by the size it's more than likely (it's also the only through-hole component on the entire board, not taking the pinouts into account).
Yeah, the HC-49S crystal is small enough to fit on the Pro Mini particularly when the smaller ATmega328P chip package is used.
Hi Julian
Would the low voltage to the hygrometer chip because of 2 regulators in series have caused the difference in humidity between the other 2 meters you had in the previous video. You had been quite surprised by the difference.
Most of my Arduinos are from Robotdyn and they come in a Strip(when you buy more than 1) with labels on it and on the back is a list and every Arduino is marked with a pen.
when is the next post bag ?
Next video - or next but one - probably.
Julian Ilett hope so :)
Those crystal oscillators look nothing like ceramic resonators, but they do the same job!
munging an arduino and a display... is there a D-duino involved?
No. The best munge will be the humidity sensor PCB onto the front of the OLED board. Fitting the OLED onto the Pro Mini will be a tad more tricky.
@julian,
Are you reading the hydro sensor to rapidly? What is the recommended time between readings in the datasheet?
There doesn't appear to be a limit on how quickly you can read the sensor. There is data on how quickly the sensor will respond to changes in RH assuming a 1m/s airflow rate.
Julian Ilett,
There are 2 parameters of timing to take into consideration:
1. The conversion time of both temp and humidity dependent on resolution.
2. Response time.
A delay between readings would be beneficial.
Can an arduino be powered by a 4.2 v battery ?
Just checked one of my unidentified Pro Mini modules, and found that it had an 8Mhz ceramic resonator and a voltage regulator labeled DE=A1D.
I have the same "DE=A1D" for 3.3v 8MHz, my 5v 16MHz have "S80D" with a symbol like a wave before !
Hi Julian,
When I want to identify a component and I can't read the markings, sometimes viewing them at an angle, let's say 40 degrees, makes it so much easier to read them :)
You also can set fuse to activate Clock output on PORTB0 (Pin 8) and then simply measure it ;)
If clock frequency doesn't have to be exact or temperature critical, you can use the internal PLL and the factory calibrated RC clock. I do it all the time. Then you can set the frequency to whatever you want. I've run 1MHz plus sleep for low power and 20 MHz for time critical applications.
I just wish there was easier access to the fuse settings via the Arduino IDE
Sounds odd but I've never used the IDE. Old school. I struggled with coming up with a working Make file and that is where the fuses get set but it may be possible to set clock speed on the fly. I have set some aspect of clock speed on the fly in init code and looped until clock status is stable to exit and continue.
See, that's why I always program AVRs via ISP, be it from the Arduino IDE or in any other way. I often get annoyed, how slow the Arduino abstraction makes everything and end up writing all the registers myself instead of using Arduino functions. As far as I know you can only change the fuses via ISP, so you need an ISP programmer anyway (usbasp for 3$ or so).
Ah, I forgot about the Arduino's boot loader. I usually end up trashing it. You can either make your own ISP or buy one off of Ebay for cheap. I found it fun to program the ATtiny and by default they are set to 1MHz so it would be common to change the fuse settings when more speed is needed. Amazing what you can do with a buck and some change and the open source cross compiler. Everyone familiar with AVRDUDE?
I you replace the 16mhz resonator with a 20mhz resonator are you considered an arduino overclocker?
20 MHz is within safe operating area, so I'd say not. Only if you go higher than that, which I've heard some people do. Standard Arduino library doesn't support 20 MHz, your delay()s, milli()s, and micro()s will be off. In most cases you'd better optimize your code instead, or switch to a faster micro. A Chinese company makes an ATmega328P-compatible MCU called LGT8F328P, that runs at up to 32 MHz. There are cheap boards available. I've heard both good and bad things about them.
My Pro Mini appears to have the resonator labeled "Ar" and the regulator labeled "S80D"
All the Arduino Pro mini that I've bought in the last 3 years are all red reset button = 3.3V, black or silver = 5V.
Wonder why, I'm talking about at least 60 pieces from about 5 different suppliers.
That's certainly not universal since I purchased some 5V 16Mhz Pro Minis a while back and they all have red reset buttons.
what is the 4BMD voltage reg.?
I have a 5V 16Mhz Pro Mini and the resonator says A4.
How does the Si7021 compare to the BME/BMP280? Same protocol? Cheaper?
I'll be looking into that - I've just bought the BME280. And the SHT30 and the HTU21D.
Please a board with regular marked S8PK regulator
i have got one with s8pl voltage regulator with a crytal marked as AC
Easy way is off course just measure the voltage: RAW something over 5V gives VCC = 3.3 or 5V.
Both pro minis I have have A something marking on the crystal... both are 5V 16MHz...
why not a Nano?
It's slightly bigger - and the USB/serial converter isn't needed once the microcontroller is programmed.
Yeah. For projects that are actually just programmed and not monitored by a computer using serial this isn't necessary. I recently made a device that measures voltage of a LiPo with a voltage divider + 0.26v since this isn't that accurate and it's about the ratio. I am using an OLED i2c to display it. It also shows the uptime using millis() and battery percentage if full means 4.2 v. Love the channel btw.
Well I have lost and found my ftdi too many times. I like Nanos.
I hope you will be identifying your USB/serial converter for us, with pinouts etc. I bought a handful of these Pro Minis but got the wrong converter/programmer.
In the back of my head you have a video where you present a few of these, but I couldn't find it.
Julian Ilett yes it's smaller but what about when you add headers. It makes it a tad awkward in size. Do you remove them or have some sort of pogo pin setup.
why did you call them ceramic resonators, they are quarts resonators, aren't they?
The tiny metal cans are ceramic resonators - 3 terminal devices with integral load capacitors.
thank you
I prefer Arduino Nanos. No mucking about with serial to USB converters, it's built in.
John Ridley then use a micro
***** Why? Nanos work very well. I especially like the screw terminal breakout for them, it makes it great for putting them into control environments. Plus the Nano is about $3. What does the micro do that the Nano doesn't?
USB Keyboard / Mouse / Joystick "emulation"
***** Sure, if I ever need that. I have only needed that once, and I used a Digispark ($1.20 Tiny85 based).
How about battery consumption, do they consume the same, considering a Nano and a 3.3V 8MHz Pro Mini ?
the 2 5V arduinos I got have a 16.000 mark on the resonator, Im confused xD
would it be ok to change the 16mhz crystal to a 20mhz crystal? just wondering
It would probably oscillate OK, but timings for delay() and millis() would be inaccurate. As far as I know, Arduino only understands 8MHz and 16MHz clock sources, so you may have problems getting these timings right, even after altering the 'boards' file.
I think it could be possible, but i am not sure how would it effect the rest of the system.
champstyl Its possible but you have to change the cpu frequency in the boards.txt
thanks, useful info.
I saw weird Arduinos on ebay today, variously being called pro micro and pro mini but theyre not like Arduinos Ive seen before. they have the atmega32u4 but idk if theyre china versions of actual Arduino boards I wasnt familiar with or parts bin knock ups or what. item 291547273695 looks like a pro mini with all the small components shoved down one end, and items 191928750938 and 191981130271 might be the same thing with a slightly different layout, but one of them claims to be 5V 8MHz which is kind of odd. and the other has leonardo in the listing title but I thought the small form factor version of the leonardo was the micro which looks like a nano but longer and that isnt one of them. its very confusing but theyre dirt cheap so maybe I'll get a couple to have a look at
The first one is a pro mini but has two rows of pins at one end - not certain about this, but I think this provides access to the ICSP pins so you can re-burn the bootloader. The other two are pro micros (not Arduino micro) which have the ATmega32U4 chip (with integral USB hardware) and a USB socket on board.
I see, thanks. I was just looking at the Arduino site and there have been way more versions than I thought. I still like Nanos best.
The "pro mini" with the ISP pins on the end are the ones I prefer. I essentially buy them because they are an AVR+crystal+regulator+easy to access pins, not because the are an Arduino. I always get rid of the Arduino bootloader anyway and program them via ISP.
In most projects the serial-to-USB of a nano isn't needed once done, so it would be a waste of space. Since I solder in (onto another PCB) the whole pro mini board in some projects, it's useful to have easy access to the programming pins and not have to lay them out yourself.
What I do is just program them with the blink sketch at 16MHz then if it runs at twice speed I know it's an 8MHz board.
You need to determine what voltage your version operates on. The lower voltage (3.3v is 8 Mhz) the lower the clock speed (CPU). You can still do much with the lower clock speed. The same code would run on both units... So you can make the l.e.d. blink any rate you want all in the code. Julian has a great video in which he examines the "Arduino" speeds compared to native Atmels (programmed w/ ASM or C?) with AVR I think.. Very Interesting indeed!
Best Regards.
-Leap
Yea the same code runs on both but it won't run at the correct speed if the right speed isn't selected in the IDE. Voltage doesn't matter unless something is hooked up. On a 3.3V board when the serial converter is connected you can input 5V on the VCC pin and it bypasses the regulator, it only uses the regulator when you connected power to the RAW pin.
I guess you are waiting for a new oled with a more convenient pin arrangement.
Exactly :)
And because not everyone reads the comments, I'm waiting for one with the same pin arrangement as the Si7021 humidity sensor board.
Think we can hazard a guess as to why you want them in the same order. ;-)
PCB sandwich - it's gonna look awesome!
Yes, that is exactly what I guessed. I recall you doing something similar with your 'wearable' project a while back.
Recently got an arduino to play around with, but while trying to find some resources to learn about programming I was absolutely overwhelmed with information about robots and other stuff I'm not immediately interested in. Does anyone have any suggestions as to good(!) resources for starting with arduino in projects like Julian does? There's just so much information on the web that I can't see the trees for the forest...
check out the arduino playground over at www.arduino.cc
The best thing about the internet is all the free stuff and the worst thing about the internet is all the free stuff!
I recommend Exploring Arduino by Jeremy Blum which is an excellent book full of electronic circuits and code examples that are fully explained. Also look for any titles by Simon Monk.
There are loads of good websites with free information on them but there is a lot of dross also. The books I mention are well written and reliably accurate.
Got 3 of them, 2 different sources, all 5v. All three have A on the crystal
Thanks, that's consistent at least :)
Serial output will corrupt if programmed wrong frequency of selected Arduino Part. Upload serial print sketch .
My 5v clones are all AZ on the crystal
Thanks for that :)
thanks
good video
All my 5v 16mhz say 16.000 on the crystal
And the Regulator says L05
Are those Pro Minis? Not many Pro Minis have crystals due to lack of space.
yeah there are some pro minis that fit those huge hc-49 crystals on them: de.aliexpress.com/item/ProMini-ATmega328P-5V-Compatible-for-Arduino-Pro-Mini/32525859745.html
They do exist - useful if you need a very precise timing source in your project.
Julian Ilett Yes, Pro Mini, the cheapest I can find in Germany, somewhat like the One Strawberrymaker suggested
Looks like you need a
stereomicroscope
I'm amazed that none of your pro minis have a crystal. Mine does and it says YC16000M. With a tiny regulator LO5 (or LG5?). And the pins are from every side of the board, yours are mostly from three sides only. Interesting how they're inovating even those devices. Some Pro Minis out there have the tiny chip and massive crystal, some have tiny resonator and large (comparatively) chip. It's just all a bit funny.
I think the A Stands for hex 16 or 0x0A
Nice idea, but hexadecimal A is decimal 10 - it doesn't really work - which is a shame ;)
Julian Ilett jep, my fault^^
Why don't you just hook em up to a low supply voltage (5 volt to start with) and look for a 3.3 volt output ? Save a lot of pissin' around.
Hi Julien,
All my 9 ProMinis have either the KB50 or the L05 as 5V regulator. 4 of them came with ceramics marked AT and AQ (just like yours) and the other 5 actually have a full size crystal on board marked 16.000. apparently I don't have any 3V3 ones.
Cheers!
That's my collection:
imgur.com/ghoVNcH
OK, thanks for that :)
👍
You also have a 3.3v output on the arduino so the extra module was really not needed. Great work otherwise. :)
The extra module also provides level-shifting on the I2C pins, not just a 3.3V step-down on the power! It wasn't needed as those level-shifting components were present on the sensor board but it would be necessary if you were to interface a 3.3v sensor board that doesn't contain level-shifting to a standard 5V arduino uno, nano or pro mini.
Nick B oh you're right, forgot about the signal voltage! Slipped in the thoughts! 😂
You wouldn't need a level shifter for the signal even when hooking up a 5V Arduino to a 3.3V sensor. Just make sure you don't put out 5V on the I2C pins and use external pullups to 3.3V (you would need the external pullups anyway). An AVR running at 5V "understands" 3.3V as logic high.
get a white text marker :)
resonator = AT REG=BALF
first!!
dammit!
third
it would have been much better if you had spent 10 minutes beforehand making some notes so that it sounded like you knew what you were talking about instead of rambling about.