Resistor 220 ohm

Good morning,
I am trying to do the first project of the book but I can't find the resistor of 220 ohm !!

Is it my fault ? cause I am beginner in this field.

Thanks you all,

Which book ?
Which project ?
Where do you expect to find the resistor ?

Can you find any resistors? Do you know what a 220 Ohm resistor looks like?


Look up “Resistors” on page 8, then follow the link to the color table.

If all you're doing is lighting an LED, you can use any resistor from 220 ohms all the way up to 10k ohms, if the LED is bright (efficient) enough.

Did you look in the back of the drawer?

It sounds like you have a book and a kit of parts.

There are dozens - probably hundreds - of book + board + parts sets available; all it takes to make such a kit is a supply of boards, parts, and books. What they include, and what the exact projects are, vary - so you should always specify which one you are using - ideally, link to it. Also, even knowing the title of the book, with so many books, you're unlikely to find someone here with the same book - so I'd say a photo of the connection diagram that you're using would also be a great thing to include when asking about a project in a book.

Note regarding books, too: The book is presumably a "getting started" type book; the experienced people - you know, the kind of person who you want answering your questions - even if that's how they got started, and even if they happened to use the same book you had back then, there's a good chance that they wouldn't have it anymore. The people with the same book are probably not as well placed to answer questions as people like, say, me. I gave away a 2-inch thick basic-intermediate level book on Arduino (OReily arduino cookbook) because by the time I got it, I felt like I already knew what was in it.

I also have a sneaking suspicion that most of the masters here did not learn via an intro book. I knew basic electronics (but not microcontrollers) since elementary school courtesy of my father, who was an electrical engineer, and like 5 years ago got an Espruino board on kickstarter because these microcontroller things sounded like they would make doing complex things with electronics practical - Espruino made it really easy to get the hang of microcontrollers, by virtue of having a real-time console to type commands into and see the result (you pay the price though in needing a much more expensive board, yet having performance that is in some cases worse than an arduino with a much less capable chip that sells for $3 for a clone). Once I was more comfortable with microcontrollers, I moved most of my work to Arduino and became a deep expert on that, because I like making lots of small cheap projects, and then went "all in" on attiny's because I saw an opportunity to contribute by making board packages to support all the less-loved ones on arduino and become the expert on those parts. I am strongly driven to master systems and become the expert in a specific area - I like building frameworks and making tools way more than I like making actual projects :stuck_out_tongue: The only books I got that I liked were ones specific to embedded C (my C knowledge was pretty weak when I started) - most of my learning was online (but like I said, I definitely had an intuitive understanding of how electronic circuits worked - I think getting this is by far the most valuable background skill - though I can't say I can recommend anything to teach it). A bunch of other books I got, didn't like, and gave away.

I also have a sneaking suspicion that most of the masters here did not learn via an intro book.

And I would concur. :grinning:

Most of us who are in a position to authoritatively answer questions have a much longer history in microcomputer and microcontroller operations.

After my introduction to the PDP-8 at school, I started with my own build of the SC/MP with 768 bytes static RAM, the Challenger-1P, a university project 6809 Exorciser with a complete we-write of FLEX-09, the CoCo 2, MiCoCo, PC clones and on including FORTH, thence the PIC and then Arduino, starting with a Pro Mini clone.

My instructional "books" are datasheets collected over more than 40 years.

When I criticise the misuse of interrupts as I often do here, it is because I know disk driver code. :roll_eyes:

I started with my own build of the SC/MP with 768 bytes static RAM

That took me down memory lane.

Writing opcodes in a column on coding sheets of my own design, converting them into machine code in another column including calculating jumps manually, entering the code into the board (a Sinclair MK14 in my case) one by one and tentatively running the program. For a couple of months I did not have a way of saving or loading programs until I added a cassette player interface.

Happy days

OT: My boss at first job had an SC/MP kit, and that got me hooked. (c.1976)
I bought a Signetics 2650:ev board (big mistake!), but had to learn more than I needed.
Also did the PDP-8 / PDP-11 route, and onwards.

The thing I notice that surprises me is people choosing a platform that is unsuitable for their project.
OK, it may have been available, but will never be efficient or cost-effective at the role, and may last 6-12 months before it comes crashing down.

One thing I love about working with micros is the need to ‘understand’ the problem, and most ways of solving it - BEFORE choosing hardware and writing code.

You get to explore and study so many aspects of everything.

That took me down memory lane.

Hi, I’m guessing you have the Arduino starter kit? Me too - eventually I figured out the 220 Ohm resistors don’t look like the pictures in the book. They are the blue ones like this pic. Hope this helps someone out!!


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