USB Jack & Interface

Don't feel like you have to understand this part fully! Skim it for now, and consider it a resource for you when you want to take a deeper dive into understanding the hardware!

The USB Jack and Interface is next up in our tour

There's a few parts here.

USB Jack

As we talked about in the beginning, this is how you connect your Arduino to your computer. You can use any computer with a USB port. You will need a cable to connect! This cable is usually not included.

Make sure your USB cable matches the Arduino. Arduino UNO uses a type B cable, a Metro uses a Micro USB cable


A HUUUUUUGE number of people have problems because they pick a 'charge only' USB cable rather than a "Data/Sync" cable. Make 100% sure you have a good quality syncing cable. Srsly, I can't even express how many times students have nearly given up due to a flakey USB cable!

I can't stress it enough. Make sure you have a good USB cable. Naughty USB cables will really ruin your day, like a stone in your shoe. Just thow out bad cables and replace with a good one - they are designed to be disposable!

USB Inteface Chip

OK so you plug your Arduino into a computer with a USB cable. But you may be surprised to learn, the main processor chip (ATmega328) cannot speak "USB". Instead it can talk an interface language called "Serial". Serial is a much simpler, much older interface. (It's also a lot less expensive to build into a chip) So, how do you connect a chip that does not speak USB to a USB port? Easy! you just need a USB to Serial Interface Translator chip. Much like a human translator, it can understand and speak both languages and can seamlessly translate between the two.

The USB to Serial translator or converter is just a necessary evil to get an Arduino to talk to a computer. Sometimes to save space and money, there is no USB/Serial chip on board. Instead, a USB to Serial cable is used. The cable is more expensive but you can use it over and over. There's a lot of different translator chips, some common part numbers are FTDI FT232, FTDI FT231X, CP2102 or CP2104, PL2303, CH430 and probably a dozen others. They're all nearly identical but some require different operating system drivers.

Powering over USB

 You can power an Arduino using a USB wall adapter - these come with almost every phone and gadget these days. They have a nice clean 5V output. Some have an output up to 5.5V but thats OK. Basically, if it has a USB connection it will power your 'duino just fine!

You can sometimes power an Arduino project off of a portable USB power pack but these packs are often designed to charge a phone and the Arduino uses so little power that it will cause the pack to think that it is "done charging" and auto-shutoff

So, try it out but your mileage may vary.

Last updated on Jul 14, 2016 Published on Jul 14, 2016