I would use a microcontroller, for instance Atmel ATtiny ( [1]8 pin
version) to replace the relays needed to keep track of 4 states, and an
[2]L293 dual H-bridge motor driver to drive the two motors in forward
and reverse directions. You would need 4 pins to control the two motors
DJ,
while reading your comments about gschem and pcb requesting ALL the
'packets' that match the partial information in order to fill in gaps
reminds me of another minor problem I have with the occasional work _I_
do. I usually start with an Atmel microcontroller and add on parts
I have not been following this closely, so let me make a guess at what
the basics are, and in so doing through my little 2 kopecks worth in.
If there were a combined, heavy library with both circuit element
symbols and footprints contained within a single grouping for a single
For some reason, I can not find the keyboard shortcut to increase the
width of the selected trace/line. I know I _used_ to use that shortcut
a whole lot, but now I have to go through the Select pull-down menu
each time, so I am not tweaking the layout as much as I should I tried
the
I just started up again using gschem after a long break, and was
surprised to see a new feature called magnet net. I general, it was
great, but it also caused problems. I started with probably an
undersized title block, and the page rapidly got stuffed with just a 40
pin ATMega and
The second problem I had was the pins on all objects, dips, connectors
and power symbols alike, were offset from the grid. When I used snap to
grid for net lines, they would never connect without magnetic net,
which was causing its own problems. Any idea how reducing the grid size
Kai-Martin Knaak,
Thank, that cleaned things up a whole lot! I had noticed a 3 stage
toggle, but did not understand the third mode and so avoided it. Now, I
agree that it seems to be the best idea for default. Thanks again for
the help and quick reply!
Mike
--
Burn the
Collin,
with snap to grid not set to R and the lines and pins lining up, I
won't need the magnetic net as much. I agree, it often short cuts to
the point of making routing other lines hard or even making false net
connections. I had not thought of holding down CRTL while zooming
I have fixed up the schematic with the help from above, but when I try
to transfer it to pcb, the element groups have almost nothing in the
open line (which is usually a parentheses rather than square braces)
and the item name, value, etc at at the bottom inside a trailing
I noticed that all the footprints were coming from the m4 processor. I
did a --help, saw that -s suppressed m4 processing, ran it again with
fresh files, and suddenly the whole file loads and disperse all
actually has something to disperse. Sorry about the previous bandwidth
I have excess muratic acid/hydrogen per oxcide etch solution after
making a
board. What is an acceptable way to dispose of it?
The hydrogen peroxide
is easy to neutralize; just put a piece of charcoal in the bottle
and
it should decompose. First pour water
Very nice design. I see you have managed to keep it to a single layer
board. Very tough to do with so many signal pins. Now I need to design
a shield for it that control motor driver H-bridges to control a
practice robot for our FIRST FRC competition!
Mike
I do not know much about fluorescent tube ballasts, but I can give some
general guesses.
1) Wattage is going to relate to total amount of heat dissipation that
the ballast can handle.
2) Tube length (each in parallel or both in series) relates to the
voltage needed to first
as I am now for the Underwater Robotics Competition.
The one in Space and Naval Warfare Systems Center? I watched some of
the
races on youtube. Seems like the task is getting harder over the
years.
No, actually this one is a spin off from that one. One of the local
On May 31, 2010, at 11:30 AM, Mike Bushroe wrote:
2) I found that several IC have no power. I know that John Doty
does
not like to have his schematics cluttered up with surperfluous
Vcc and
Gnd connections.
No, I (and others) tend to use separate power
I have the PCB layout pretty much arranged and was just starting on the
power traces when discovered some more problems.
1) AT some point I must have shorted something out, because several of
the bypass caps now have BOTH pins glowing green for being part of the
Vcc net. I have not
OK, I have the layout. I found that some symbols don't have explicit OR
implicit power connections. Others use VDD and VSS instead of Vcc and
GND. I found where I have moved a component slightly a caused a short
between ground an power. I got all that fixed. But every time I start
It seems that you had really much trouble -- more than me in the
last 3
years since I started using gEDA/PCB. Maybe you can make a summary
of
the most serious problems and someone can put that list in the wiki.
Unintended use of M4 macros seems to be one of your
Are you footprints in the directories you indicate, or
subdirectories
of the directories you indicate?
Are you running gsch2pcb project to use that project file?
You might also have a file name that matches an M4 macro name. I
like
to put a suffix on mine to
John, thanks for the advice on input/output connections. Last year when
I did this, I rolled my own H-Bridge motor drivers, and used hierarchy.
This year I am simplifying things a little, and using the Solarbotics
2AMP Dual motor drivers instead. Hierarchy still would have work well
I still
NEVER managed to get any footprint libraries added, even after
using gafrc
in /gaf, gafrc in /motherboard, setting the PCBLIBPATH environment
variable
Those don't set the paths! You have to pass them to the file
gsc2pcb
reads, which I name *.prj.
I am just transitioning from gschem to pcb for a robot controller board
I am making. It spans several sheets, and has never successfully been
exported by gsch2pcb. One of the error messages is cannot find file
ROV_2010_analog.sch. This is one of the sheets in the overall
I was trying to make footprints for the screw terminals I am using in
my current project. They are on 5 mm spacing, not inches, so I was
hesitant to start with a different footprint and try to change it for
fear of getting the units mixed up and creating a mess. So I switched
PCB to
Thanks DJ. The first part of that looks familiar. I guess I never read
down far enough to get the footprint creation. I now realize that my
problem was that the menu did not indicate that converting the buffer
to an element converted vias to pins. I had no idea at all how the pin
John,
Thanks for the clarification. I checked and I have created a unique
'name':'number' for each net attribute, and matched input to output
names. If a net is formed for each unique name:number, and all inputs
and outputs with that unique name are combined together, then that
Thanks and DJ and John. Now I finally begin to feel comfortable with
creating footprints in PCB.
But I am still finding another problem with getting the whole pile to
translate. I have made or downloaded several custom symbols and
footprints. But not matter how many times I insert a
John,
Are you even reading my posts? You comments, even when directly
connected to quotes of my own text seem completely unrelated and non
sequiturs, and often self contradictory.
On Apr 27, 2010, at 5:43 PM, Mike Bushroe wrote:
John Doty: These refer to the device
I guess part of my problem with gschem, pcb, and gsch2pcb is that I
never understood what gattrib was for. I though it was an internal
function used by gschem and gsch2pcb to get the values of symbols
attributes out of the schematic file. I never realized it was intended
for humans
John Doty: These refer to the device, not the pattern of copper on
the board. The pattern of copper corresponding to a given device
footprint should be chosen in the layout process, because it depends
(like other layout parameters) on the manufacturing processes.
I am
No, that's not what I'm talking about. Footprints depend on the
layout tool: gschem is properly agnostic about what layout tool
you're using.
John Doty Noqsi Aerospace, Ltd.
[1]http://www.noqsi.com/
[2]...@noqsi.com
So that means the shortcoming is
I think it's far more important to have the symbol browser import
symbols into the *project* (not the schematic) as they are selected,
so they can be customized as necessary. And it should pop up an
annoying information box reminding the user to check the symbol
until the
I have recently joined another open-source, open-hardware group working
on self-replicating rapid prototypers ([1]RepRap) they were also hoping
to get supported in this years Google Summer of Code. And I think that
they have a worthy project (and have already addicted me to trying to
Does anyone know why there is no button or menu command to create a
full circle in PCB? I know that the file format actually describes arcs
as fractions of a circle, and that it can just as easily be a 360
degree fraction as the 90 degree limit imposed by the GUI. But when
making
I am also mentoring a FIRST Robotics team. We have already had one
session on trying to learn gEDA/PCB and have them etch their own boards
using the PCB-in-a-box kit. But since most are running Windoze or MAC,
most of the time went to just configuring a KNOPPIX live CD loaded with
Mark,
how doy you call the python script? You gave some nice screen shots of
the results, but my quick look through the code I did not see an
example of how to call it. Does it only do 45 degree rotations, or is
one of the arguments the rotation angle?
Also, will this work
Cut to buffer
:FreeRotateBuffer(45)
Paste
GREAT! Wish I had seen that feature last week when trying to get the
button battery holder to fit on the backside between the 14 pin DIP
and the 12 LEDs. A 45 might have just hit the spot. Thanks, I'll
rotate a few symbols to try it out.
I have been working with a High School Robotics team, trying to teach
them how to design their own circuits using gschem and board layouts
using PCB Fab in a Box to etch the boards. But no one practiced before
the workshop, so no one got to see their board own board made. To make
I am once again wasting hours of time fighting to find a way to get
custom footprints to be recognized by the software. I keep tweaking
gafrc in .gEDA, and in the project folder, and adding lines to the
project file itself. At one point, I had gsch2pcb report looking for
element
of keeping a directory of sym links just for a project. That
would help with simpler names, too.
Mike B
On Mon, 2009-10-26 at 11:48 -0700, Mike Bushroe wrote:
Is there any plan to add a footprint library to gschem
similar to
the component library, or the foot print
I have been having a lot of trouble with this too. gschem does not
have a library search routine for foot prints, and so I often create
schematics that gsch2pcb fails to find many of the foot prints and I
have to struggle to find the foot prints, sometimes type in huge long
names
will start asking questions here.
Mike
On Wed, 2009-10-14 at 09:36 -0700, Mike Bushroe wrote:
WOW, that looks nice! And having that might help me to remember that
PCB keeps defaulting to putting the rat lines on the component
side
for a single sided board, so when I
WOW, that looks nice! And having that might help me to remember that
PCB keeps defaulting to putting the rat lines on the component side
for a single sided board, so when I finally produce the board, I have
to turn it over and flip all the components.
Mike
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