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February 7, 2011
News - Some MariaDB -> Postgr… |
about 4 months ago
I’m glad to see PDO is being used and a good thing. Around here, university students, professors, web develops, etc. mostly have little or no knowledge about PDO, and thus shun it as if it is some kludgey basement hackery not meant for proper development.
Product DEV-12077 |
about 5 months ago
512 Bytes DRAM? Is this missing a prefix, since it can apparently run Ubuntu still?
Product COM-10727 |
about 8 months ago
These are typically meant to hook up to female blade connectors. If you want to solder to them, scuff the metal with sandpaper until it is all copper - solder will now stick easily :)
They’re not copper on the surface because copper is too soft for connectors and will also oxidize, so there’s some sort of harder (and harder-to-solder) metal over the copper.
Product SEN-11574 |
about 10 months ago
The LED will use all the current it can, that’s why LEDs need a current-limiting resistor.
This design has a 470ohm resistor. If I make a very wild guess (knowing it’s a green LED) that the voltage drop through the LED will be about 2.4V, and we know I (current) = V (voltage) / R (resistance), we get I = (5.0V-2.4V)/470ohm = ~5.5mA, which isn’t far off the given current spec.
Generally, the max current spec of an LED is an absolute limit. You can run it anywhere below that :)
Product TOL-08967 |
A bit late on the reply, but common household hot water tanks hold water around 60C (140F). Basically all that is needed hot tap water that isn’t super hard, and a brush wouldn’t hurt. Deposits from hard water could cause problems, but unlikely for hobby use.
Product TOL-00082 |
I didn’t get these from SparkFun, but have what seems to be an identical one from Princess Auto, so keep in mind I’m speaking about potentially different ones. Also keep in mind it is heavily used every day in an open University electronics lab.
It works great, much better than the giant plastic one we had before.
I don’t think the body is metal, just shiny-painted plastic, but it really doesn’t affect the performance. The button lets the spring do its work without getting caught up, the tip doesn’t melt even with the iron cranked to max, and it’s all still looking new after much punishment.
The threads holding it together look questionable, but we’ve never had to take it apart. They don’t get loose by themselves either.
Honestly, it’s a good product if it’s the same as we have. For $4, this is seriously decent. I usually detest cheap tools, but these work well!
Oh, and it doesn’t really clog. Once in a while if you’re just dumping solder into the thing, it can be a push to get everything out, but that’s abusing the tool a bit.
News - SparkFun National Tour Ki… |
about a year ago
If you guys make raise a huge amount extra… stop in Canada too? :)
News - New Product Friday: Cubel… |
about 2 years ago
I have the “normal” (Arduino form-factor) Maple, and can offer a few opinions. Keep in mind I don’t use shields so those aren’t important to me.
The IDE is the same, the language is the same, the library has some small (and very welcome) differences. For example, use of analogWrite() is replaced by pwmWrite() (much more accurate English, plus Maple Native will actually have a DAC on it (so I hear) to possibly use a real analogWrite()). The integer types are different of course, being a 32-bit architecture; keep typedefs or use the ones existing for uint8, int16 etc. to have to avoid porting integer types.
There’s some pin issues with certain shields; a Google search will help you determine shield compatibility, and so will LeafLab’s site/forum.
That said, the ChipKit UNO (SF, please look into carrying?) runs a hair faster clock (80MHz PIC32) that seems to get a huge digital I/O speed boost over the Maple. I assume one does not largely excel in number crunching over the other though.
I’d do a full comparison of benefits between Arduino (Uno), Maple, Arduino Pro Mini/Micro, and Maple Mini, but I only have two of those devices. Maple is a great platform, and it’s nice to see something Arduino-like in hardware/programming concept with more power, and yet breaking away from the restrictive Arduino form factor. Personally, I liked the multi-function pin arrangements so that I could have 14 analog lines easily :)
News - March Caption Contest |
about 2 years ago
“Really Ma, the dog ate my parts and I need more!”
Product COM-11102 |
about 2 years ago
Not quite. The starting torque above is ~0.14oz-in. Compare that to a few motors you may or may not have to get an idea of how much that is.
Also, that’s starting torque induced by stiction (or static friction). If it’s moving, it experiences classic or dyanamic friction, which is always less than stiction. The difference depends a lot of the mating materials. Let’s just say it’s 0.1oz-in, which may be completely off (in either direction).
If you had 5oz-in of torque at near-stall (but still rotating), you’d still be delivering 4.9oz-in to the rest of the system. Of course this may do a little damage to top speed, especially true of brushed DC motors (due to how they operate), but it’s not designed to be used on cheap, weak brushed motors. Think more torque-y big motors and stepper motors.
Also keep in mind the encoder weighs 100g (~3.5oz), so you’re probably not going to be putting two of these on a robot with low-torque motors anyway. In that case you generally do not need this much resolution and can actually make a cheap encoder yourself :) (Google, perhaps? Quadrature Encoder is usually what people are looking for)
No public wish lists :(