Shield's Standard and who have the best one?
tonyp12
Posts: 1,950
Propeller Quickstart have a pretty bad shield, the RadioShacks only review stated that it's not compatible with anything.
Arduino is of course pretty common standard but probably have flaws and could be improved?
MSP Lauchpad is pretty good.
If creating a new standard:
It needs to use the new dual entry smd headers, so you use male pins to select what signal goes up or down to next shield making shield conflicts less problematic.
Allow half-shields, so you can mix and match 2 smaller shields without stacking, so Vcc and Gnd is repeated once in pinout at the middle
5V pin should be included.
pinout compatible with SPI OLED screens, so just pop it in without wires
I like this one best as Vcc before gnd, as many others is opposite but all i2c versions Vcc is before gnd.
http://www.ebay.com/itm/White1-3-SPI-Serial-128X64-OLED-LCD-LED-Display-Module-for-Arduino-UNO-R3-/281687207054?hash=item4195ddac8e
Going metric with 2mm headers is little bit to bold move, but could be made as an option and let the market slowly move to it.
Any thoughts?
Arduino is of course pretty common standard but probably have flaws and could be improved?
MSP Lauchpad is pretty good.
If creating a new standard:
It needs to use the new dual entry smd headers, so you use male pins to select what signal goes up or down to next shield making shield conflicts less problematic.
Allow half-shields, so you can mix and match 2 smaller shields without stacking, so Vcc and Gnd is repeated once in pinout at the middle
5V pin should be included.
pinout compatible with SPI OLED screens, so just pop it in without wires
I like this one best as Vcc before gnd, as many others is opposite but all i2c versions Vcc is before gnd.
http://www.ebay.com/itm/White1-3-SPI-Serial-128X64-OLED-LCD-LED-Display-Module-for-Arduino-UNO-R3-/281687207054?hash=item4195ddac8e
Going metric with 2mm headers is little bit to bold move, but could be made as an option and let the market slowly move to it.
Any thoughts?
Comments
Agree that the Quickstart header isn't the best. To me, the pinout is not intuitive at all.
Arduino's layout has become a standard simply by the sheer volume of "shields" produced using the flawed design. The design error was never given the chance to be addressed because add-ons were already created. Hence, fixing the design flaw, meant impacting third party designs that were driving sales.
Launchpad is acceptable, but not a total win. Proof in point is the Propeller Platform that never made it big although looks very similar. It was clean and usable, but for some reason was slow to be accepted. Parallax pushing the Quickstart platform may have helped it's demise as well (cost)
I agree with most of your "new standard" ideas. There have been a few 10 pin concepts that were well thought out. 8 for I/O, and 2 for VCC/GND. Repeated in a 20 pin gives you 16 IO and a standard ribbon cable can be used as well. Do you recall SpinStudio? It was a 20 pin per bank design that left some unused pins, but gave 8 I/O, 5v, 3.3v, and GND at each block.
http://forums.parallax.com/discussion/96843/the-spinstudio-development-system-is-available-now
Be careful following add on hardware pinouts. As you mention, there are lots of variations. Plus, following an eBay/China standard is scary in itself. If your product is designed to be used with super cheap eBay add-ons, then your product better be cheap as well (in many eyes).
Stay away from 2mm. A dev board needs to be a dev board. In other words, compatible with prototyping hardware that nearly everyone has such as perf boards, breadboards, ribbon cable style jumpers, etc.
http://forums.parallax.com/discussion/comment/1203199/#Comment_1203199
What happened with the Arduino simply appears to have been in the right place at the right time to take advantage of a glut of chips that had been superseded by better product for actual industry use. (It is quite absurd if you at how many different Arduino processors there are now for a so-called educational mission. Too much retailing and too many variations to allow teachers to keep students focused.)
Volume and the availability of chips in large quantity at clearance prices ended up with all the Arduino shields that are out there. And Chinese hopeful of overtaking the whole hobby electronics by investing in huge runs.
But are these the kind of boards that really can be deployed in use 24/7 for reliable service? I think not. The majority just introduce some novelty and aren't going to do much else. And the majority don't even have documentation.
+++++++++++++
For a long time now, I have stepped away from the whole stackable board scheme as too restrictive. Cables and wires bridging from board to board are capable of making what seems incompatible construction, work quite well and reliably.
It may not be as compact or mindless, but it does work -- if all and everything is spaced at 0.1".
So I feel that 0.1" header spacing is far more important that the next great 'de-facto' shield standard.
I really have doubts that anyone made much money off of the Arduino shield form factor, except for a few that were early and precise in what their application was... like 3D printers.
The Propellino (sp?) finally was one of the few to address that deficit. The Propeller 2 is supposed to provide built-in ADC.
There was also Andre LaMothe's C3 board that included ADC with a lot of other features packed into a creadit card size (I disliked the intense packing that creates problems with adding on that are easy to avoid.)
In the meantime, just about any Propeller Board that would provide a basic Propeller functionality, and an 8-bit wide ADC would be welcome to most that just want to explore micro-controllers in general. Other features might be good to, but not as critical to wide acceptance.
I guess what I am saying is that part of the wide-acceptance of the Arduino was NOT the shield design so much as the ADC included within the basic board. I am not even sure adjusting i/o logic from 3.3V to 5.0V is even an issue any more... so much is 3.3V logic with 5VDC compatibility.
There will be half-shield only dev board when space and cost is a factor, that will only use 2 of the headers.
There is a 0.2" gap between the two headers that are on the same side, it also helps with counting pin position.
So 56pin total on a max board: 8pin power + 24pin gpio + 8pin ADC + 10pin QSPI + 4pin I2C + 2pin Reset
But also two 6pin card edge connector (probably shared with spi & i2c)
http://www.mouser.com/ds/2/1/ts2192-47491.pdf
The propeller Activity Board has a 4 channel 12 bit ADC (5 v reference) and a 2 channel DAC (0 - 3.3v). There are tutorials which use these on the Parallax Learn pages.
Tom
It is a good board, very worth owning. No everyone desires an Activity Board. But many have projects that need a few ADC inputs. The Propeller ASC board will do that, and can take a generic Arduino shield to interface with added power bus.