I've just received my first Arduino Duemilanove and it works like a charm. But it's been a VERY long time since I have worked on a project like this and so I have several very simple questions:
The Arduino has 16 digital pins (2x8) and 12 (2x6) analog/power pins. What connector can be used to plug into these pins? The Radio Shack guy suggested AWG 24 solid copper telephone wire. This works, but it's loose and I would prefer something better. What's the standard connector called, and where can I buy it online (or at Radio Shack if they have it)?
There are three mounting holes in the Arduino board, each of which is about 1/8 inch in diameter. What's the best way to attach the Arduino board to a container? Nylon screws (Radio Shack didn't have any)? Metal screws with nylon washers (I tried this but the Radio Shack washers were too thick when I got them home to try them out)? Metal screws alone (but what about the danger of shorting out the board)? There is very little clearance between the holes and adjacent board components.
What's the best container or box to put the Arduino Duemilanove in, hopefully with a hole for the USB port? I”m hoping that some vendor sells a clear box designed specifically for the Arduino. Is there one somewhere?
Related to the above, how much heat does an Arduino generate? Can the Ardiuno be put in a closed container/box, or does the container need ventilation holes?
The connectors are called header connectors. Check Digikey and Mouser for
single row headers. I would use stranded wire rather than solid. It is more flexible.
A good place for small screws and standoffs is MSC Direct and McMaster Carr.
If the holes are not plated then either a metal standoff with a nylon washer or a
nylon standoff should be fine. Use phillips screws (if possible) and hex standoffs.
See this for some flexible jumper wires: they're stranded in the middle, but they attach some solid core tips at the perfect post size for a good connection without damaging the header holes of your Arduino.
The holes are 3mm, just right for M3 nylon bolts, or nylon spacers. Not sure where you are, and not sure if M3 metric bolts are available in the USA.
The Arduino is a very low power device, comapared to a PC or similar machine. It'll be fine in a closed box, although the 5V regulator may get a little warm if you feed it from a power supply that's close to the maximum.
Thanks for your suggestions and sorry to be so uninformed, but I'm still confused about the best male connector to use to connect to the Arduino board. The flexible jumper wires from Fungizmos.com suggested by halley will be great for prototyping and experimentation.
But what should I use for a more permanent connection? I am thinking perhaps of a ribbon cable with a male connector that will plug into the female analog and digital connectors mounted on the Arduino board (if there's a better or more typical way to connect a cable or wire to the Arduino board, please let me know. What do other people do? )
JLuciani suggested checking Digikey and Mouser for “single row headers” but Digikey lists 380 items under that heading, and I don't really know which to choose. Mouser is similar. Can anyone recommend a specific source for a six or eight conductor ribbon cable with a male connector on one end that will insert into the female analog and digital connectors mounted on the Arduino Duemilanove? Or do I have to make such a cable myself? And if so, how would I connect “single row headers” to the ribbon cable (or anything else)?
If there is a tutorial about this admittedly basic and simple process, please direct me to it. Nobody else that I know is using these boards, so I have no other local source of information.
"Single row headers" are a row of square metal pins, 0.1 inches apart. You'll have to solder them to your ribbon cable manually. Use a bit of heatshrink sleeving to insulate the joints and make a bit of strain relief.
It's actually a bit of a limitation of the Arduino that there isn't a better way to make a permanent connection. The header pins are not fixed onto the Arduino at all, and will pull out under vibration or if the cable is pulled. If you want a really "industrial strength" permanent connection, you'd have to solder wires on, or make a shield that simply connects wires to header pins. Shields can be fixed down with small bolts, making the connection really stay put.
Sorry I can't specify part numbers for you, but I don't use Mouser, and I'd rather not recommend something I haven't used myself.
Thanks, Anachrocomputer, for your response. I am surprised that there is apparently NOT a better or standard way to connect to the Arduino board. It has so many interesting features that I would have thought that there would have been a variety of readymade connection options. If not, then I guess I'll have to improvise and try to find out what others have done.
Finally, what is a "shield"? Do you have a picture or example of a "shield" showing the associated screws or bolts used to attach it?
The friction of the pins provide the only mechanical connection that is usually needed.
I used to work on sonar systems, and they were regularly shipped around the world, by air freight. One system was returned to us after having a fork-lift truck drive through it, forks first. So I'm probably a little more aware than most of the ways in which a connector can come undone!
(I'd better not go into all the times we got salt water into the 300V DC power supply!)
Yes, friction is fine to hold an Arduino connector in place in nearly all situations. But there are cases when we need to have a positive retention mechanism for a connector. Places where there's high vibration, for example, or where the Arduino is mounted upside-down. In that case, the shield (daughterboard) needs to be held on with screws or bolts. Or maybe a cable tie all the way around both main board and shield.
Do you have a picture of how the daughterboard is attached to the Arduino, including the screws, washers, and nuts that you use? I have some online sources (previously suggested) to check, but since there is such little clearance between the screw holes and adjacent components, I'm still a little uncertain which ones will work.
I don't have a purpose-made shield, but I did find a bit of Veroboard, a few header pins and a couple of nylon M3 spacers. The photos are on Flickr, here:
The short M3 nylon spacer (M3 is the size of the metric thread, to fit through a 3mm hole) is 8.25mm long over the hexagonal part, and the longer one (female thread both ends) is 12.5mm long. The short one is a bit too short, and the long one is a bit too long! A better length, if you can find it, would be 10mm.
Hope that helps! BTW, does anyone know how to make an image on the forum, that is also clickable as a link?
I'd say if you wanted to permanently mount a second PCB next to the Arduino (for a flatter, wider footprint) ribbon cables with IDC headers would be good: google "single row IDC header" shows http://www.avx.com/docs/Catalogs/8284.pdf - better than trying to solder to headers, but finding small pin count IDC to pin headers is tough. This is permanent and sturdy enough that it is common in DVD players, car stereos, industrial equipment, computers, etc.
If you want to mount the second PCB above (like a sheild) you can use breakaway pin headers (these solder to the PCB you make and plug into the female headers on the Arduino) - which would most likely be a secure enough mechanical coupling in and of itsself, but you can really secure them together if you use standoffs/spacers to bolt the boards together.
These are both standard methods used in any number of designs in all of our homes, jobs, and wherever we go in our daily lives!
The common component, though, are the pin headers (whether IDC for ribbon cable or breakaway for direct PCB soldering) - these are 0.100" (2.54mm) and you can get them at a local electronics shop or electronic component distributor if you're lucky enough to have a thorough one around! If not, to give another link out to SparkFun: Break Away Headers - Straight - PRT-00116 - SparkFun Electronics
The "break away" means that you just cut them to the number of pins you want.