Though the Arduino is a great device, I would like to see these improvements in the next generation of Arduinos:
Mini-USB port: Though the classic Type A USB is used for printers so people generally have them, they are bulky and generally do not have wall socks to power them unless a wall powered USB adapter is used. The Mini-USB is much more common being used with mobile phones and small devices. With this port we can use our mobile phone chargers to power our Arduinos and have a smaller less bulky port.
20 MHz Clock: Fast clock means faster calculations. Though it may use more power, it would be nice to still have an option to have then to be stuck with just a 16 MHz clock.
Crystal instead of Ceramic: Crystals are more expensive and require external capacitors, some of us like to have precision with our designs. >:(
I've gotta disagree with this one. Yeah, it's smaller, but in my experience much much less reliable, especially in situations where I'm hacking with lots of wires and board and parts jumbled together, i.e. a typical arduino session.
I will admit a prejudice for crystals vs. ceramic resonators and a desire for 20MHz operation.
I assume you're talking about the Uno in relation to crystals, every version of the Arduino up to the Uno had crystal oscillators. I've no problem with ceramics on small/cheap clones but the real thing should have a crystal. Changing the clock speed is going to kill a good proportion of third party libraries and cause general mayhem with compatibility with all earlier models, I doubt the average arduino user whose sketches are full of delay() is likely to notice the improvement. So leave it where it is. Another vote for the standard A-B USB lead here.....
Another vote for the standard A-B USB lead here.....
There are only a couple of reasons that I can see the justification for the mini-USB connector:
Availability of power adaptors/wall warts with a mini-USB plug output.
No worries about a shield "shorting out" with the mini-USB jack.
Now, number 2 can be eliminated fairly easily with good board design and/or a piece of electrical tape; kinda hackish, but it works.
Number 1 does have a bit of merit, though. Maybe instead of changing out the connector, a source of wall warts could be found that have a Type-A jack? I know they exist (or existed in the past), because my USB Cybiko had such a setup (although I think its total current output was only 200mA?). So - maybe if we can find a source of such jack (with a larger current output - say 500mA), then we can have the best of both worlds, so to speak.
Maybe tonight I'll try out that Cybiko wall wart and see how well it can power my Arduino (It'll probably work OK, as long as the current needs are low)...
Mini-USB is the main reason I buy Seeeduinos (other than a low profile, cleaner layout, side-accessible reset button, reliable manual power source switch, standard header spacing option). I have maybe three USB-B cables, but countless Mini-USB-B cables and power adapters.
Maybe instead of changing out the connector, a source of wall warts could be found that have a Type-A jack?
Like those that come with the iPhone and iPod Touch? I here there are a few of those around...
dealextreme has them, rated at 1000mA even, for around US$3.
Type B seems to me to have a "more positive" (less negative?) attachment than the mini connectors.
I've had enough problems with friction-fit cables that I want a positive latch on every connection - screws (ala DB9) or some other latch (like the RJ series tabs).
Maybe tonight I'll try out that Cybiko wall wart and see how well it can power my Arduino (It'll probably work OK, as long as the current needs are low)...
Mine charges my bluetooth mouse just fine, It should have an output current at least as good as a PC usb port (500mA officially).
Micro OTG B would be best if looking to converge onto a connector type. This connector is the becoming standard for mobiles. The main difference between the micro and mini is for lowest profile, i.e. as needed in mobiles.
Regarding the comment about reliability, its my experience that the SMT connectors are unreliable where they solder to the PCB.
This is especially the case with USB seeing as they are unplugged and plugged in again, and again, and again!
So, my top pick would be a Through hole Micro (less preferably Mini) OTG B connector.
its my experience that the SMT connectors are unreliable where they solder to the PCB.
It's my experience that they are unreliable where the plug meets the socket long before any solder joints fail. Very small dimensions coupled with mass-production tolerances and low cost manufacturing do not combine to give a reliable connection.
could always put on one of each... or possibly put down the second SMT footprint but don't populate in production - only there for those who really want it
truth be told, where I work we are sticking with the standard B connector because it truly is a robust connector in all aspects...
@ZNahum: "precision" is not an absolute term but a relative thing. How much precision do you really need? A resonator, a crystal, an OXCO, a frequency normal, a GPS locked frequency normal? More precision usually means higher price and often higher power consumption.
Most "precision" requirements for the Arduino can probably be handled most appropriate with an external high precision RTC.
I also like MiniUSB-B.
I have another board, Arduino USB and not MiniUSB-B was replaced with the basics.
Universal Japan board has a 1.27mm pitch
Able mounting the connectors are relatively easy to use staggered diagonally.
I can see a picture of shaking.
I have several Mini USB cables laying around, but I have to unplug my Printer whenever I use the Arduino with the Large USB - B cable.
(I refuse to buy one as THE ONLY DEVICE I use besides my laser printer that needs the cable is my ARDUINO)
Not to mention i have countless wall warts (Cell phone chargers) that use that plug, not to mention car chargers, that make in vehicle operation very easy.
The micro plug would be nice as well, but I'm not sure it has enough market share (beyond cell phones) to warrant it. (Despite being higher quality, smaller, and more durable)
If that helps a bit with the debate between Mini vs. Micro USB, here's a quick tally I did by thinking of devices I own.
Inventory of Large USB type B devices:
1 laser printer
If I'd do a random inventory of items that use Mini USB I'd come up with:
4 Cameras
1 Radar detector
3 portable navigation devices (Garmin Nuvi, TomTom, Mio)
2 external hard drives
2 Blackberries
2 Ipod chargers
1 mini speaker system
__
15 devices that I can think of of the top of my head.
Micro USB
1 Droid cell phone
1 external hard drive
_
2 devices that I can think of.
In the end, maybe an online vote might help sway the designers of Arduinos. Please understand that having a large plug is not a dealbreaker, but it is an inconvenience.
I'd prefer micro USB, but I'm willing to settle for mini USB. It's the one detail on the Arduino that bothers me enough to consider clones. (I like the Freetronics clone design.)
I'm a complete hardware newbie, so I can't even imagine constructing my own cable to interface with the USB port.
I'd be interested in having RTC onboard, along with networking.
