Show Posts
|
|
Pages: 1 2 [3] 4 5 ... 14
|
|
32
|
Forum 2005-2010 (read only) / Development / Re: LCD shield and/or LCD serial backpack
|
on: March 20, 2008, 12:34:41 am
|
|
Copper finishing nails and a block of wood make an ideal test bed. I find the easiest method is to place the PCB over the block of wood and drill _tiny_ holes through any vias/holes in the board and through the wood (use a drill press). From this I can usually bang copper nails in nice and straight.
How you wire the test bed is an exercise for the reader. Perhaps an Arduino pumping data into the board and also emulating an HD44780 comparing input to expected output?
|
|
|
|
|
36
|
Forum 2005-2010 (read only) / Development / Re: Arduino serial with MAX232 or equivalent?
|
on: March 10, 2008, 11:02:39 pm
|
The version number should be V2.0 or superior, as the changes from V1.0 justifies the new version number I think you're right, 2.x makes sense. what PCB design software do you use to make those nice looking 3D images of the board I use Eagle. The 3D mock-ups come from the Eagle3D ulp and POVRay. It can take some futzing to generate exactly what you're after, but it works. I find it most useful to uncheck "parts" in the Eagle3D dialogue and use it to generate PCB only renderings like these. I know there's a Protel/Altium tool to do the same. I think I will also add the 3.3V regulator I used a 78L33, simply because I have them in inventory. Sadly there doesn't seem to be a standard for 3.3V regulators, the 78L33 is only made by ST. Other manufacturers make other regulators, and you may find a better choice for you; I found most to be pricier and require larger stabilizing caps. A different regulator may have a low enough drop out to run from the 5V rail though instead of Vin.
|
|
|
|
|
37
|
Forum 2005-2010 (read only) / Development / Re: Arduino serial with MAX232 or equivalent?
|
on: March 10, 2008, 04:22:01 pm
|
 After finalizing the BOM, these are just waiting to join a panel. (Now I need to do real work so I have something justifying a panel  ) The only strange component left is the 3.3V regulator (78L33) and the short caps. Expect boards whenever they come back from the fab-house, and kits whenever the parts come in. Actually, is there anyone who'd prefer I didn't use "Freeduino Serial"? There could be confusion with the existing (transistor or otherwise) Freeduino Serial boards.
|
|
|
|
|
41
|
Forum 2005-2010 (read only) / Development / Re: Small arduino "standalone"
|
on: March 23, 2009, 02:18:39 am
|
You can play with it later, but almost all MAX232-like chips will work with 0.1uF caps for the charge-pump and storage caps (C1, C2, C4, and C8 in your schematic), if the smaller caps mean a change from electrolytic to ceramic you may actually see better performance out of the MAX232 due to the much lower ESR. Really though, modern MAX232 chips are pretty resilient, as long as you get the caps in there, they'll usually work. The reset part would be a very welcome feature... Take a look at the MaxSerial schematic for an idea of how this could be implemented.
|
|
|
|
|
43
|
Forum 2005-2010 (read only) / Development / Re: A StickDuino shield Adapter
|
on: March 24, 2009, 02:13:55 pm
|
I honestly didn't know how much demand there'd be for a stickduino sheild. I didn't expect the "small USB stick sized" crowd and the "shield prototyping" crowd to overlap much. A few quick ideas though: - Cross talk shouldn't bee too much a concern at the speeds the Arduino switches at. Outputs are also usually driven against less than 10K of output impedance.
- The 3 VCC pins are only present on original stickduinos, recent stickduinos have "VCC, RESET, and GND" in the top left instead.
- With all the board space available, you could add a prototype area or a small boost converter.
- The Stickduino has 17 pins/side. Unfortunately, 17 pin female headers are basically non-existent. You might consider using two 16-pin headers and just ignoring the extra ground on the lower right and the extra VCC on the upper left.
Feel free to hit me up for some collaboration.
|
|
|
|
|
44
|
Forum 2005-2010 (read only) / Development / Re: Standalone Arduino Problems
|
on: March 23, 2009, 12:02:19 pm
|
|
Both the RTS and DTR lines are asserted by the IDE to cause a reset. The DTR line is asserted (pulled low by the FT232) when opening the terminal by any application (unless you take great pains not to). I honestly can't remember how or why RTS is set, but it is. I recall some trickery with Windows to set RTS on close.
The FTDI cables that are ever-present only provide the RTS line.
|
|
|
|
|