Learning arduino stuff?

[julianf]

Elegoo seems fine.

Im just trying to work out between esp32 and the uno. Seems 3.3 vs 5v inputs is the only "issue"?

(i mean esp32 is "larger" but its not like you have to use all the extra stuff)

For some reason, the esp32 elgoo kit is cheaper than the uno, for the same compliment of "stuff"

 

[Misterg]

Elegoo seems fine.

Im just trying to work out between esp32 and the uno. Seems 3.3 vs 5v inputs is the only "issue"?

(i mean esp32 is "larger" but its not like you have to use all the extra stuff)

For some reason, the esp32 elgoo kit is cheaper than the uno, for the same compliment of "stuff"

I'd honestly stick to the Uno for your first steps. It's more expensive, because genuine Arduino Unos are about £25.

Get the hang of programming: flash a few LEDs, make some noises, get 'Hello World' to show on an LCD, spin a motor, etc. Then use a different board if it suits your needs better.

The 3.3V logic level of the ESP32 (and many other boards) isn't a serious handicap, however it differs from the age-old 5V logic used by the Uno.

Add-on boards (like sensors, stepper drivers, displays, etc.) for "Arduino" always used to be 5V, and many beginner / tutorial circuits assume this to be the case. Some of them will work with 3.3V logic, some won't. Some are dual voltage, some aren't. Some require 'level shifters' to be able to interface 5V devices to a 3.3V board. It's all do-able, but (if I'm guessing your current knowledge somewhat accurately) it's a complication that could catch you out and lead to frustration.

I2C devices (often used for Arduino add-ons) will work on either 5V or 3.3V, but both ends of the bus must be the same (or you need a level shifter).

Examples included in the starter kit:
The 1602 LCD display requires 5V logic;
The ULN2003A stepper driver* requires 5V logic.
etc. etc.

Processor speed and memory are complete non-issues for some time to come.


(*The ULN2003 IC is limited to 0.5A per phase and gets quite hot at less than this. It will work a stepper driver for low speed / low torque applications, but it's quite likely that you'd want a dedicated stepper driver for anything other than the lowest load / slowest applications.

ETA: Example of a dedicated stepper driver:

TB6600 Stepper Motor Driver with Arduino Tutorial

In this tutorial you will learn how to control a stepper motor with TB6600, AccelStepper and Arduino. Many example codes included!

www.makerguides.com

The programming for this is slightly different, as you just need to supply step and direction pulses, rather than control each motor phase separately with the ULN2003, but build the ULN2003 circuit, learn about steppers and move on if you need to.)

(Oh, and the TB6600 expects 5V, too...)

Sorry to keep harping on!

 

[Dev]

Finished the IR receiver I mentioned.

Well I say finished<it’s working just needs a case - but the 3d printer is busy.

 

[skotl]

Elegoo seems fine.

Im just trying to work out between esp32 and the uno. Seems 3.3 vs 5v inputs is the only "issue"?

(i mean esp32 is "larger" but its not like you have to use all the extra stuff)

For some reason, the esp32 elgoo kit is cheaper than the uno, for the same compliment of "stuff"

There's no wrong answer but, FWIW, I started with Arduino and quickly migrated (upgraded?) to ESP. The main reasons were built in wifi, ESPNow (very low power / cheap / easy board to board comms) and processing power relative to (most) Arduinos.

I've never had a problem with it being 3.3V - quite the opposite as the battery options, especially LIPO or cells, are easier to handle with ESP. Also, I think (but could be wrong) that deep sleep on the ESP can mean many years on a single battery.

As far as the fewer number of pins on the ESP are concerned, there's two easy ways to overcome this:
1. I2C where multiple sensors can be on the same two pins together
2. Just use a different ESP for each task

I tend to do #2 and they talk ESPNow (over a distance of up to 200m) to a single ESP32 that converts their messages to MQTT and then transmits over wifi to my Home Assistant install.

BTW, totally get that a lot of that may sound like gibberish so, in summary, neither the 3.3V or fewer pins is a particular barrier to utilising ESP boards.

...and Arduinos are good, too

 

[Dapph2]

So what sort of things do thse Arduino's do or make work .

Telling me /us roughly in a single sentence answer for each question part would be very helpful .

 

[minimutly]

So what sort of things do thse Arduino's do or make work .

Telling me /us roughly in a single sentence answer for each question part would be very helpful .

Anything that you want to control with bits, outputs etc or for communication point to point, or to display values ( ie from your car), or timing - eg firing the ignition on an engine, or pulsing injectors. Measure, decide, doo.
Damn, too many sentences...

 

[skotl]

So what sort of things do thse Arduino's do or make work .

Telling me /us roughly in a single sentence answer for each question part would be very helpful .

You can use them to control a single thing, or to simply act as inputs and outputs to another system that manages/orchestrates them.

Example of the first kind: an Arduino or ESP32 with a couple of push button sensors and an output that goes to a DC/DC converter can be used with a powered sit/stand desk: one button for up, one for down, and an output to a servo that drives the motor. Extra kudos for wiring in limit sensors.
That's a standalone "microcontroller".

The other side is more complex, requires more software, but arguably has more power: use them as discrete sensors and switches with something like Home Assistant to create a smart home.
In my house, for example, I have:

Multiple proximity sensors that trigger a "movement in room" message to Home Assistant ("HA").
HA knows what time of the day it is so if it's between dusk and dawn then it turns the light on in that room.
When there's been no movement in that room for 20 minutes, HA turns the light off.

Another sensor measures the light in my office window and sends that to HA. HA controls the blinds on the window when it gets too sunny.

Multiple sensors on the doors transmit open/close messages to HA. HA knows whether we're home or not based on where our mobile phones are, and pings me a message if a door opens while we're all out.

A sensor in the garage measures the temperature and pings HA if it drops below 2C. HA then sends a message to another ESP with a relay to shut off the dehumidifier.

A sensor simply listens to four buttons on my extending microphone stand and sends bluetooth HID (keyboard) shortcuts to my PC to increase/decrease volume, mute my mic and mute my camera so I can manage Teams calls while (literally) leaning back in my chair.

Food for thought

 

[Misterg]

So what sort of things do thse Arduino's do or make work .

They're just another microcontroller: They look at inputs, make some calculations and set some outputs.

I think they owe their popularity to a few things:

Flexible I/O - pins can be inputs or outputs; digital or analogue, etc.

Standardised board formats;

The Arduino IDE programming environment. It's a simplified version of C++ that completely abstracts the programmer from the complexities of microcontroller architecture (so the same program will run on an Uno, a Nano, an ESP32, or whatever has an appropriate library in the IDE).

The documentation, tutorials and support that Arduino created for their original boards, and their adoption as an educational tool.

And because of the above, the sheer number of ready to use peripherals and supporting software libraries that are available at very low cost - It's the computer equivalent of Lego.


I was a late adopter - I considered a full blown microcontroller to be overkill for most of the applications I needed. A couple of logic chips and some analogue electronics would do the job with far less fuss.... If I needed a microcontroller a £5 PIC16F84 would cover a lot of ground... Until you figure out the time taken to design the circuit; prototype it to prove it out, design a PCB and get it made, and then assemble the board. Even at £25 an Arduino board would be far, far cheaper - an off-the-shelf board and a couple of software iterrations = job done. Assembly level programming of a 16F84 could take hours to get all the bugs out (and yes, there was an undocumented problem with lookup tables crossing page boundaries that took me *days* and a lot of hair to figure out!).

Shortest answer: Computer Lego

 

[skotl]

So what sort of things do thse Arduino's do or make work .

Telling me /us roughly in a single sentence answer for each question part would be very helpful .

Oh - just thought of another specialised solution that I posted on here a while back.

Post in thread 'Stuff your 3D printer has made today...'

Nov 14, 2023

Today I made (well, technically, "today I finally finished after five weeks of toil...")... a surface mount solder hot plate!

Fusion 360 with a mighty 15 components:

An ESP8266 (actually a wemos d1 mini), thermistor, 250C hotplate, couple of fans, buck converter, I2C display, a relay and several hundred lines of C++ code:

Exposed guts:

And the end result!

I used ABS for the hot box and then separated the controller (made of PLA) by some standoffs and conduit. Totally over the top as it turns out, as the innards of the...

• skotl

• 

You can see ESP8266 (the ESP32's younger brother) board in the bottom right of the enclosure picture - it's wired to an OLED display and some buttons on the front.

That's a SMC (Surface Mount Component) solder plate where you paint a circuit board with solder, mount the (tiny!) components and then heat the entire board. The solder reaches a flow temperature, then you cool it and the "reflow" seats the components on the board.
Each type of solder has a specific heat and reflow temperature curve, which I programmed into the ESP. You select the appropriate curve on the display, hit start, then the ESP turns the power on and off on the 230V heating plate to match the desired temperature, based on elapsed seconds and the desired curve. There's a thermocouple on the heating plate to let the controller know what the current temperature is.
I learned a lot in that project, including what "hysteresis" is!

So defo not a single sentence answer but I could never have achieved that without using either an ESP or an Arduino.

Fun fact: three buttons, a 230V relay, a temperature sensor and an OLED display all controlled off the meagre pins on an ESP - who needs an Arduino....?

 

[Misterg]

I've used an Uno for a lithium ion battery capacity tester,a tachometer,a temperature logger, and loads of other stuff that was set up temporarily.

A Leonardo for a force-feedback steering wheel and pedal input for computer racing sims;

And ESP 32 for

CAN bus to analogue display (LCD module with integrated ESP32):

3 axis CNC controller:

(It engraved its own front panel)

And various other bits and bobs.

It all starts with being able to turn an LED on and off and send "Hello World" to a display.

 

[MattF]

"Hello World"

If it were I, I just know that's not the message I'd use.

 

[RichardM]

So now im going to have to delve into this world of magic and spank even more

Interesting.

3.3v supply, ATX desktop power supplies have a 3.3v rail, maybe useful as a development power supply.

 

[Misterg]

Interesting.

3.3v supply, ATX desktop power supplies have a 3.3v rail, maybe useful as a development power supply.

Supply isn’t an issue - the boards in question have built in voltage regulators.

The 3.3v thing concerns the logic levels used to communicate. It’s a very minor / none issue once you know what you’re doing, just something that might trip up someone without any electronic knowledge trying to work through a tutorial / copy a circuit design.

 

[jmp49]

Yep with arduino its all about the ide, tools for the pc to program it, the tutorials etc. Arduino is actually copyright to some company that used to have a non profit vibe, but is now owned by qualcom. They've pulled a few tricks making the ide not work with clones at times, so I'm in two minds about their benevolent dictator position, and screw it, I want to use clone boards everywhere after that.

ESP32, later to the party and piggybacks onto the arduino ide amongst other methods, but it just does more, better, less consumption, more capable and is physically smaller but you have to use the right tutorial and design when your starting out because arduino got lots of people interested in and playing with small embedded boards first.

Start with the one that matches the tutorial you want to follow for your stepper, later on buy the other type and play with it too & decide for yourself which is the better option, theyre both less than a pizza to buy if you count clones.

 

[jmp49]

Also if you just want to flash someone elses design, instead of getting into the whole ide and seeing the code etc, you can just flash one right from your browser (chrome etc, but not firefox sorry).

ESPBoards ESP32 Program Uploader Tool - Web-Based Utility

Upload firmware and programs to ESP32 and microcontrollers using the ESPBoards Program Uploader Tool, a web-based utility accessible directly from your browser.

www.espboards.dev

Home assistant has espdevice builder as a add on that does the same thing, plug in a esp32 device, and pick one of the predone device designs or edit your own and just flash it right in your home automation system

 

[jmp49]

Sensor simply listens to four buttons on my extending microphone stand and sends bluetooth HID (keyboard) shortcuts to my PC to increase/decrease volume, mute my mic and mute my camera so I can manage Teams calls while (literally) leaning back in my chair.

Thats exactly what a shelly i4 does (well it can do bluetooth, wifi or zwave...) , and its just a esp inside, except it comes in a fancy plastic snap together case and has passed electrical certification, so if it burns down your house, you dont get arrested and the insurance cant wriggle out of paying out because of "homemade electronics"

Shelly Wave i4 US LR | Z-Wave Long Range 4 Digital Input Control for Advanced Control | Home Automation | High Compatibility | Easy Installation | Shelly Smart Control iOS Android App | Multi-Click : Amazon.co.uk: Business, Industry & Science

Shelly Wave i4 US LR | Z-Wave Long Range 4 Digital Input Control for Advanced Control | Home Automation | High Compatibility | Easy Installation | Shelly Smart Control iOS Android App | Multi-Click : Amazon.co.uk: Business, Industry & Science

www.amazon.co.uk

 

[jmp49]

2016, a uno and some sainsmart relays in 3d printed case.

Local control via wired in buttons into inputs and appearing on the ethernet network too with its own little embedded web server. it could be sent instructions to remote switch via a homemade api too of course but not by mqtt or anything yet as this was 10 years ago and I hadnt fell down the whole home-assistant rabbit hole and was still writing all my home automation stuff myself. I wrote this arduino code from scratch...


Things spiral... Lets make it do 8 relays, breadboarding connectors, run off poe ethernet power, and wouldnt it be nice with a tft display that only lit when you touched the touch sensitive screen (which was a display designed for a smartfone...), and a move to the mega in place of uno for the extra io/memory. I had a firmware on there that let me remote flash them too, so I didnt have to get up a ladder to change the config or code...


Later on I migrated that same sketch to use a epaper display to save power but no photo of that.
Currently I'm making a esp32 act as a serial port bridge using esp home builder in home assistant, because my vintage consoles use a kramer RCA video switcher thats serial or IR only, and I want home assistant to be able to select which console is displayed, once its turned on the psu for only that console, and turned on the projector to the right input, and selected the correct channel on the audio amp. Obsession... But anyone has the tools available to do anything now at a bargain price to entry.

 

[ajlelectronics]

So what sort of things do thse Arduino's do or make work .

The question really needs to be phrased differently. What would YOU like it to do, within reason?

I have made all sorts of custom devices that suited my requirements at the time. Test equipment; one example being a test box to determine the control codes used by car radios to overcome the manufacturers refusal to supply them. It just sits there and "brute force" blasts all the options at the radio until it gets a response, then narrows it down to a smaller range before single stepping.

My BMW iBus radio converter is the recipient of that data, which allows owners to sling the original radio in the K1200LT and replace it with a modern type, without losing the remote controls and dash display.

Pardon our interruption...

 

[ajlelectronics]

Another interesting project was to enable my garage doors to know "which way is up". That allowed me to interface them to voice control and so open the doors from the car when near to home, just by telling Alexa to do so.

I needed a way of knowing where my aerial rotator was pointing and didn't want to use the conventional synchro or potentiometer methods. In this case, I incorporated a "compass chip", an Arduino Nano and a Bluetooth transmitter into a tube on the mast. It was powered by a cable, but I could have used a 5V solar panel.
The compass passed its position to the shack controller and have me a digital readout of position and options of driving to a specific or common position. That worked well.

Amateur radio applications are manifold too. I have a number of communication controllers and interfaces. Two or three RTTY decoders and encoders have been built and used. I also use the (comparatively expensive) Teensy board for RTTY terminal units, which are fully working but currently being refined. These use 5" or 7" colour TFT displays.

 

[jmp49]

Nice, there's a esp32 project on github that lets you bridge between the peugeot 207 phase1 steering column stalk controls and the canbus & control and reset the dash clock and do other deep functions via a little embedded webserver/hotspot combo once you've fitted a android head unit, since peugeot put all that hardware inside the original radio too. My daughters been pestering me to make it for her, but I've been a bit busy with my cnc and also making the wife's SPA controller appear on and be controllerable from homeassistant (its a balboa gs controller, and the hardware sits between the button panel display and the controller, and intercepts it, and injects fake keystrokes to set mode/temp etc )