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Arduino Uno R4

blog.arduino.cc

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Re: Arduino Uno R4

#81

Post by kayson »

dragontamer wrote: post #15
dale_glass wrote: post #5

A nice improvement, but maybe too little too late? I mean, what's the point? An ESP32 has 320K SRAM, 448K Flash and a 240 MHz dual core CPU. And it costs peanuts. That's the competition to beat, and this doesn't reach it, even though the ESP32 came out in 2016. The Arduino has been resting on its laurels for too long, I'm afraid. There's long been things out there much faster and cheaper, and with wifi out there for…

But an ESP32 can't turn on an 2N7000 MOSFET. 2N7000 is a 5V MOSFET, and is the cheapest one to boot, and one of the easiest to use.

There are bajillions of mosfets; you can certainly find another one that works even if it's a tiny bit more expensive.

Re: Arduino Uno R4

#82

Post by guenthert »

dragontamer wrote: post #15
dale_glass wrote: post #5

A nice improvement, but maybe too little too late? I mean, what's the point? An ESP32 has 320K SRAM, 448K Flash and a 240 MHz dual core CPU. And it costs peanuts. That's the competition to beat, and this doesn't reach it, even though the ESP32 came out in 2016. The Arduino has been resting on its laurels for too long, I'm afraid. There's long been things out there much faster and cheaper, and with wifi out there for…

But an ESP32 can't turn on an 2N7000 MOSFET. 2N7000 is a 5V MOSFET, and is the cheapest one to boot, and one of the easiest to use.

Wut? From the data sheet:

"ON CHARACTERISTICS (Note 1) Gate Threshold Voltage (VDS = VGS, ID = 1.0 mAdc) VGS(th) 0.8 3.0 Vdc"

Re: Arduino Uno R4

#83

Post by kevin_thibedeau »

londons_explore wrote: post #61
kevin_thibedeau wrote: post #52

Earlier quoted context omitted.

5V is the special feature but it only has 20mA sink/source on two pins. That's not particularly friendly for typical Uno applications.

The original ATMEGA328p may have said in the datasheet that it could only do 20mA for 2 pins... But in reality, you can short all the pins to GND and then output high on all of them, and the chip survives indefinitely (although does get rather hot!). It's really rather nice and robust.

The ATmega supports 40mA on any pin. This is about the Renesas part.

Re: Arduino Uno R4

#84

Post by hd95489 »

More power but still no rtc on the baseline. The 12 bit dac is an improvement for pulse width modulation.

Though I’ll be honest I think most people use these for smart switches and power modulation devices so better dac is nice.

Re: Arduino Uno R4

#85

Post by ThrowawayTestr »

Avamander wrote: post #66
dale_glass wrote: post #5

A nice improvement, but maybe too little too late? I mean, what's the point? An ESP32 has 320K SRAM, 448K Flash and a 240 MHz dual core CPU. And it costs peanuts. That's the competition to beat, and this doesn't reach it, even though the ESP32 came out in 2016. The Arduino has been resting on its laurels for too long, I'm afraid. There's long been things out there much faster and cheaper, and with wifi out there for…

The ESP32 and ESP8266 are significantly more complex and come with a bunch of downsides that make an already difficult venture into the "hardware land" even more so. Watchdog timeout or some other exception, you'll get a stacktrace that requires a fragile Java piece of software to decode, and it only does that to some extent. It's seriously not pleasant. In my anecdotal experience the ESPs are also not as robust agai…

The ESP is compatible with the Arduino IDE. I've found it as easy to program as any other microcontroller. (Though I have encountered watchdog issues with unoptimized code)

Re: Arduino Uno R4

#86

Post by ThrowawayTestr »

DeathArrow wrote: post #74
zamadatix wrote: post #49

Earlier quoted context omitted.

Addressing specific markets only works if you do it uniquely or better. The simplified Arduino tooling works on the ESP32, which is also the cheaper and better option.

Good point. Are there ready made ESP32 boards good for education?

Just google ESP on AliExpress. Tons of different dev boards available.

Re: Arduino Uno R4

#87

Post by dragontamer »

guenthert wrote: post #82
dragontamer wrote: post #15

Earlier quoted context omitted.

But an ESP32 can't turn on an 2N7000 MOSFET. 2N7000 is a 5V MOSFET, and is the cheapest one to boot, and one of the easiest to use.

Wut? From the data sheet: "ON CHARACTERISTICS (Note 1) Gate Threshold Voltage (VDS = VGS, ID = 1.0 mAdc) VGS(th) 0.8 3.0 Vdc"

Yeah, Vgs(th) is 3V worst-case. That's the specification for 1mA of current flow Ids, which is near useless (note: the Arduino has traditionally been able to supply 20mA+, so a 1mA Ids current at 3V is completely pointless). "th" is Threshold after all, its not when the MOSFET is usable, its when it "starts to turn on".

https://rocelec.widen.net/view/pdf/orqxwkxkq1/ONSM-S-A000354...

Figure 2 on page 5 gives you an idea of the voltages you're supposed to use. Optimal usage of the 2N7000 requires 10V Vgs (for 1.5A or more), but 5V is sufficient for ~800mA bursts. And I expect 800mA to be enough for most beginner uses.

4V might be usable, but that's well beyond the capabilities of ESP32.

Re: Arduino Uno R4

#88

Post by dragontamer »

kayson wrote: post #81
dragontamer wrote: post #15

Earlier quoted context omitted.

But an ESP32 can't turn on an 2N7000 MOSFET. 2N7000 is a 5V MOSFET, and is the cheapest one to boot, and one of the easiest to use.

There are bajillions of mosfets; you can certainly find another one that works even if it's a tiny bit more expensive.

Sure. So name one, that's cheap, readily available from many manufacturers, through hole, with 100mA+ or so Ids, low enough capacitance to be used with a microcontroller like ESP32.

Most of the good MOSFETs I'm aware of are SMT only, which is not beginner friendly. 2N7000 through hole is extremely available damn near everywhere. All companies have a clone of the venerated, classic MOSFET. EDIT: Its also been used in various beginner circuits for 40 years, so you can pickup an old book from the library and see those 2N7000 around and use those designs today.

----------

Honestly, if you're doing through-hole on ESP32, I suggest using a resistor + 2N2222 BJT instead of the MOSFET. But I think 2N7000 is easier (fewer parts, in particular no resistor needed). But that's a 5V design.

The 2N2222 also requires you to leak a decent amount of current through the Vbe / Ibe (while 2N7000 is like 1uA or less leak Vgs / Igs).

But... 5V and 2N7000 Jellybean + throughole is really easy to use. Its definitely a big advantage to Arduino IMO, and I'm glad that they're keeping the 5V driving capability in this newest version.

Re: Arduino Uno R4

#89

Post by spiritplumber »

For industrial stuff I tend to use the Parallax Propeller. It was ahead of its time when it came out, it still holds its own well (and the propeller 2 is a beast) and it can take a beating electrically.

Re: Arduino Uno R4

#90

Post by the__alchemist »

ChancyChance wrote: post #73
dale_glass wrote: post #5

A nice improvement, but maybe too little too late? I mean, what's the point? An ESP32 has 320K SRAM, 448K Flash and a 240 MHz dual core CPU. And it costs peanuts. That's the competition to beat, and this doesn't reach it, even though the ESP32 came out in 2016. The Arduino has been resting on its laurels for too long, I'm afraid. There's long been things out there much faster and cheaper, and with wifi out there for…

Once I learned how to use STMCubeMX, I never went back to Arduino. Comparing STM boards with Arduino in terms of price, RAM, Flash, GPIO, analog, ... and R4 looks like Steve Buscemi doing the "hello fellow kids" meme. I think the big win for Arduino was the ecosystem and simplicity, but the big embedded players have invested significantly in this space with tons of code examples compatible with the arduino add ins (S…

> Once you start with STM, you can switch to much more advanced boards with ease, ESP doesn't have the range.

And may be forced to. I still can't get H7s. ESP, nRF and others were barely affected by the shortage.

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