Arduino - where to start?

[RFburns]

Wasn’t sure where to post this really    . But I find the need to use an Arduino for a project (why this particular micro? well I have found some code that almost does what I need ) so anyone got some advice as to where to start ( otherwise I guess it’ll be get a module load the code and spend some time mucking with it). Should I get a starter kit ?(than what one UNO/Mega/Nano). Any help appreciated. RF

[frackers]

Depending on how many I/O pins you require for your application, I've found than Arduino nano clones from the usual Chinese retailers at $2 each (free postage) do the job nicely. I usually buy then in 10's so I have spares if I get carried away with a meter probe or stray piece of wire

If I want something with a bit more CPU power, then one of the many stm32f103c8t6 clones( i.e. 32 bit ARM rather than 8 bit AVR), which are now supported by the Arduino IDE (or the ST Micro very good STM32CubeMX startup wizard). They work out even cheaper but they can be tricky to interface as they are 3.3v I/O pins.

[oztules]

So far found the nano to be able to do anything I have needed.... less then at a few  bucks a piece it is hard to beat, there are lots of IO pins to play with, so you will have serious project to use them all up I suspect  ( I did with the salt water RO machine).

I did use mega's for 30 dollars but have not needed that much io power... so then use nano exclusively now... two or three if necessary.

Get a handful of them , load the code, and change it to what you need... or post the code and someone will help.

Make sure you get the ones with the usb port... makes things very simple for folks like me to play with..

..........oztules

[RFburns]

Great Thanks I will  give the Nano's a go 

[Pete]

Hi RF Burns, I am just getting into the beginnings of wanting to use Arduino's as well. I am not up to speed with the programming language yet but there is a simple graphical program called ArduBlock that makes the programming bit easier. May be worth a look.
good luck
Pete

[RFburns]

O.k Pete I will check that out thanks. I have orderd some units to play with so will be about a month before much happens. RF

[noneyabussiness]

Hi all, also just wanted to add, on the nano clones if you are using a lcd or led output and are running out of pins, try using a shift register or I2C , very cheap (100 SN74HC595N is about 10 bucks) and plenty of librarys pre written to support them. A strong suggestion to is start with pre written libraries and have a look at how they work, you can learn so much

[TaraByers]

Hi..i am a new user here. As per my knowledge depending on how many I/O pins you require for your application, I've found than Arduino nano clones from the usual Chinese retailers do the job nicely. I usually buy then in 10's so I have spares if I get carried away with a meter probe or stray piece of wire.If you want something with a bit more CPU power, then one of the many stm32f103c8t6 clones.

[Pete]

I have been working on my first Arduino project. I am making a Solar Hot Water controller with a nano and a 1.8" screen.
I know that I really don't need the screen to show the temperatures but still, it is my first try so it is still fun.
I am using LM335 sensors, and have a changeable differential in the program. At the moment the pump will turn on when the panels are 6 degrees C hotter than the Tank. Then when the difference falls to 3 degrees the pump will turn off.
I have found that I can get the screen to show the readings of Tank temperature, Panel Temperature and Pump status. BUT, there is a problem with running the controller off my USB port at the moment. The voltage is way down, maybe it is that the screen draws too much current for the Nano power supply or the USB but I am not getting accurate readings on the temperatures or digital states.
My LED, that is a stand in for the relay that will come later, is only glowing dull with less than 2 volts as a digital high output from my nano.
Is this normal, or do I need to supply the LED, and Screen from a separate supply?
Pete

[noneyabussiness]

Pete... for sure its current requirment.. the humble usb port can only really supply about 500ma, and personally i wouldn't put too much stock on it providing that continuously. . So maybe a external power supply would be a good idea, also make sure you have plenty of bypassing (10-100 uf caps) on everything. .. the amout of times i have personally had dramas on circuits to be fixed with a extra cap on the input/output

[Pete]

Thanks for that noneyabusiness,  I have a couple of powered boards for experimenting on the way so will see it that solves my anamolies.
What purpose are the bypass capacitors serving?

Cheers
Pete

[noneyabussiness]

Just an example. . I was implementing a networked of sorts nrf24l01 and it would work on my bench intermittently, sometimes fine, but a lot of dropped packets... they were sitting inches apart, that should not happen  .. 13ma max current draw at 2Mbps , my bench power supply is modified server psu's so handle 50 odd amp... no problem. .... well after hours of WTF is going on here etc. I read in a forum about bypassing this chip with a .1uf cap as close to the chip as possible. .. so i have a drawer of 6.3v caps there so i soldered one on and the bloomin thing never dropped another packet ..  in fact page 62 of the datasheet recommends a 4.7uf cap... even though it had it own power supply etc. The sudden current draw was enough to reak havoc on the chip. The cap would supply the power during that transition. .. so long story short caps provide power when the power supply is catching up... i hope this makes sense

[DJ]

Seems there is so much in this area that can be done with these things I'm going to have to learn them.

Can anyone recommend some good starter kits and or sites/ programs to kick off with?
Also interested in who has the things For $2 ea?  Local electronics retailers charge substantial amounts for the starter kits as well as the boards. Got to love fleabay!

I have been reading the direct panel control thread but it's way over my comprehension atm but it's something that I would like to do as well as an automated control for my oil oil burners. Even something that just shut the fuel and air off after a water tank reached a pre determined temperature would be a big help to start with and I could look at adding  Complic.... automation from there.

[MadScientist267]

I'm on "serious project #3" involving them, have had a taste now of both Uno and Mega... best place to start... hmm... I'll go with "neck deep" lol

Uno is a bit of a squeeze on resources but even at my n00b h4x0r level LOL... still has a surprising bit of bite as you get the hang of things and aren't afraid to think outside the box or at least beat one senseless with a soldering iron haha

Regardless of flavor, there's compiler puke to deal with... If you're unfamiliar with the language like I was (pronounced "still am" lol), find your way to the top of everything it throws at you and correct that issue, and half the time the rest is just the compiler trying to make sense of it's own meltdown haha I wish someone would have given me that little tip from the gitgo... and may have, probably did even... but there's what I've got to add on it. LOL

EDIT - On the displays... If you like challenges that eventually all seem to have solutions but don't mind flying nearly solo at times, the knock off shields work just fine once you find the right magic wand and wave it... At a fraction of the cost of the "real" displays... also hit and miss on description vs what's actually received, and gonna encounter a cracked screen here and there along with bent pins, but again if you're no stranger to a soldering iron and needlenose (especially with Uno), typically the actual displays are ok, good color saturation/vibrance etc and plenty bright... toss a few bucks at half a dozen for the price of just 1 of the "real fruit" ones and so far I've averaged out ahead, just some head on desk action to work out the magic trick that brings them to life.

And what's this about shifting registers? Lol That's what the iron and needlenose are for... bust the pins off that you need to move, and reroute them

That's one benefit of going with the cheap route... hack up the magic on one, apply it to the masses. Personally, I would have still run across the need to reroute pins, but it's a lot less stressful to approach a $5 display than a $35 (or more, ack lol) with your weapon of choice... None of this pin register shift thingy stuff hehehe They don't come with clutches anyway

To wit... LOL:



When you're finished rearranging an uno, it's like napalm in the morning... smells like... victory haha Draw you up a board or whatever to make the changes you want for "production runs" or whatever suits your fancy, and roll 

I of course jest a bit, and I'm far from guru on them but so far seems that however you go about them, they're fun to play with, even when WTF factor goes so far off scale that you forgot you were subconsciously monitoring it

Steve

[eidolon]

One thing to remember when making temperature reading with voltage based sensors. The usual reference is the 5V supply.  That supply voltage can change when you plug in the USB port vs external board supply.  The higher voltage will prevail.  I use a USB cable with the power wire cut and replaced with a diode.  that prevents supply differences of less than the voltage drop influencing the calibration.  You can use the internal reference, but that is only 1.1V and doesn't match up with many sensors.  It also puts you down in the noise.