misaligned grid and test points

On 1/6/2011 5:28 PM, Jay Beritz wrote:

I created a schematic with just a single Analog Devices ADIS16209 now I

need test points. I will be using Keystone miniature color coded thru-hole

type. .100 Dia.

http://www.keyelco.com/pdfs/M55p51.pdf

What is the equivalent in Eagle? I tried some of the built in test pads but

they don't show dimensions. I tried keeping a standard default 0.1 inch

grid. When I create the schematic everything aligns but when I create the

board they don't align with the grid why? This is my my very first board.

The schematic must always be on a 0.1 grid or it won't work. The board

grid is totally separate and the routing grid is another grid setting.

You can set the layout grid to whatever you want in order to place the

footprints or other objects where you want them. The routing grid

determines how easily the components connect, it should be maybe 5 times

smaller than the smallest hole/pad spacing you have. Making it finer

makes more complicated and slower connections, too coarse and the

autorouter won't be able to complete the connections.

On 1/7/2011 1:17 PM, Gary Gofstein wrote:

On 1/6/2011 5:28 PM, Jay Beritz wrote:

>> I created a schematic with just a single Analog Devices ADIS16209 now I

>> need test points. I will be using Keystone miniature color coded

>> thru-hole

>> type. .100 Dia.

>> http://www.keyelco.com/pdfs/M55p51.pdf

>> What is the equivalent in Eagle? I tried some of the built in test

>> pads but

>> they don't show dimensions. I tried keeping a standard default 0.1 inch

>> grid. When I create the schematic everything aligns but when I create the

>> board they don't align with the grid why? This is my my very first board.

The schematic must always be on a 0.1 grid or it won't work. The board

grid is totally separate and the routing grid is another grid setting.

You can set the layout grid to whatever you want in order to place the

footprints or other objects where you want them. The routing grid

determines how easily the components connect, it should be maybe 5 times

smaller than the smallest hole/pad spacing you have. Making it finer

makes more complicated and slower connections, too coarse and the

autorouter won't be able to complete the connections.

In the library testpad.lbr you can find the parts you need, pick the

package that closest matches or exceeds the hole size on the keystone

datasheet.

I create a new schematic

I select add

I de-select Smd's in the search parameter and search for test pad

I expand the search result "testpad"

Under "TP" I select the fifth choice "TPPAD1-17"

The three boxes to the right in the "add" dialog don't show me any drill

sizes. If I go ahead and add it then right click and go to properties, I

still see nothing that tells me the hole size.

Where is this information?

I add the test pads and wire them to the chip.

File -> Switch to Board, "And let Eagle create the board from  the

schematic."

I change the grid size to 0.01 inch

I move the chip and pads into position.

I route the chip's pads to the test pads.

But no matter what I set the grid to, the center of the chip pads and the

center of the test pads will not align to the grid.

When I do a Errors check it it's says: Errors(0), Approved(0)

Shouldn't it say Approved(1) or more?

Also when I'm I have the board open I'm looking at the chip from the top

down correct?

--

Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.

On 1/8/2011 8:16 PM, Jay Beritz wrote:

 

I create a new schematic

I select add

I de-select Smd's in the search parameter and search for test pad

I expand the search result "testpad"

Under "TP" I select the fifth choice "TPPAD1-17"

 

The three boxes to the right in the "add" dialog don't show me any drill

sizes. If I go ahead and add it then right click and go to properties, I

still see nothing that tells me the hole size.

Where is this information?

 

I add the test pads and wire them to the chip.

File -> Switch to Board, "And let Eagle create the board from the

schematic."

I change the grid size to 0.01 inch

I move the chip and pads into position.

I route the chip's pads to the test pads.

 

But no matter what I set the grid to, the center of the chip pads and the

center of the test pads will not align to the grid. When I do a Errors

check it it's says: Errors(0), Approved(0)

Shouldn't it say Approved(1) or more?

Also when I'm I have the board open I'm looking at the chip from the top

down correct?

 

>

You are correct that the board view is showing you a view from layer 1

down through to layer 16 (or whatever your bottom layer is).   The chip

view will depend on whether you placed the part on the top or bottom of

the board.   If its on the bottom then all the text (name,value) for the

component will be mirrored.

I think you need to make sure that your component pin pitch is an

integer multiple of the board grid.   This should allow you to place the

component on grid.

The number and type of errors/warnings that you get from DRC will depend

on the settings you used when you ran DRC.

jiml

Page 7 of the data sheet shows a pin pitch of 0.670 mm

http://www.analog.com/static/imported-files/data_sheets/ADIS16209.pdf

Create schematic with default grid size of 0.1 inch "everything aligns"

File -> Switch to Board "Let Eagle create the board from the schematic"

Set grid size to twice as small as the pin pitch ( 0.670 / 2 = 0.335mm)

Still nothing aligns to the grid. Also you didn't say, where is the drill

size information for the test pads?

--

Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.

On 1/9/2011 3:04 PM, Jay Beritz wrote:

Page 7 of the data sheet shows a pin pitch of 0.670 mm

http://www.analog.com/static/imported-files/data_sheets/ADIS16209.pdf

 

>

Create schematic with default grid size of 0.1 inch "everything aligns"

File -> Switch to Board "Let Eagle create the board from the schematic"

Set grid size to twice as small as the pin pitch ( 0.670 / 2 = 0.335mm)

Still nothing aligns to the grid. Also you didn't say, where is the drill

size information for the test pads?

If you use the library editor to open testpad.lbr you will find that

most of the devices are Pads and are composed of an SMD so there is no

associated hole.     There are a few devices which do have through-holes

(eg P2-38-17.pac).   If you use library editor to open the package and

use the info tool to select the hole you will see a display which gives

the hole diamter (0.067 for the above referenced package).  For the

TPPAD1-17 the P1-17 package is used and this part also is indicated as

an 0.067 hole.

I do not know why your cannot place your component so the pins are on

grid.   Perhaps the origin of the package is not placed correctly

relative to the pin locations so that when the origin is snapped to the

grid the pin positions are still off?

jiml

Well I couldn't find a test pad with the drill size I need but there's a

Keystone library with the part I needed on the Cadsoft site so that saves

me some trouble.

ftp://ftp.cadsoft.de/eagle/userfiles/libraries/keystone.lbr

Now for the board I'm having trouble with the "IC1" being in the way of the

trace. Is there any way to move it without copying the whole part and

creating a new version? Because I didn't create it I don't get the option

to smash and reposition it.

--

Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.

On 1/8/2011 5:16 PM, Jay Beritz wrote:

 

I create a new schematic

I select add

I de-select Smd's in the search parameter and search for test pad

I expand the search result "testpad"

Under "TP" I select the fifth choice "TPPAD1-17"

 

The three boxes to the right in the "add" dialog don't show me any drill

sizes. If I go ahead and add it then right click and go to properties, I

still see nothing that tells me the hole size.

Where is this information?

 

I add the test pads and wire them to the chip.

File -> Switch to Board, "And let Eagle create the board from the

schematic."

I change the grid size to 0.01 inch

I move the chip and pads into position.

I route the chip's pads to the test pads.

 

But no matter what I set the grid to, the center of the chip pads and the

center of the test pads will not align to the grid. When I do a Errors

check it it's says: Errors(0), Approved(0)

Shouldn't it say Approved(1) or more?

Also when I'm I have the board open I'm looking at the chip from the top

down correct?

 

>

sorry my mistake, the through hole test pads are in solpad.lbr not

testpad.lbr. The only reason I can think of that a single pad will not

center on a grid point is that there is an error in the part, ie the

origin of the part in the library is not in the pad center.

The board grid does need to be a multiple of the chip pitch in order for

the pad centers to be on grid points, but this is not required to route

the board ( although it will look nicer if you do it ). Sometimes you

have parts on the board which can not be routed on the same grid, then

you need to switch grids when routing if you want it to look neat. But I

don't recall that pad centers have to be on grid points.

In eagle, when manually routing it is usually better to start /from the

pads/. If you can't reach the other pad from because of a grid clash,

then just stop in the middle; go to the other pad and route from there

to the middle ( on grid) point. Neither end is required to be on the

grid. The grid just sets how often you have an opportunity to turn a corner.

I don't like to pick parts from the ADD dialog for the reasons you

mentioned, I usually look through the libs in the control panel where I

can see all the packages and ADD it from there, especially if I don't

know what it is called. Remember eagle is translated to English and if

you're american you have the added confusion of european terminology for

the same component. it's hard to know what it is called elsewhere...so

how do you know what to search for unless it's a part number? So, mostly

I use the control panel.

Adding the chip "ADIS16209" from the control panel or for the "add" button

doesn't make a difference the silkscreen "IC1" still shows up and is in the

way when I do the routing. Eagle won't let me smash the part to move it so

I guess I'll have to copy and create my own version.

You didn't say, do you know how close to the edge of the board I can have

silkscreen or parts when using the Pentalogix board service.

--

Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.

On 1/10/2011 5:29 PM, Jay Beritz wrote:

Adding the chip "ADIS16209" from the control panel or for the "add" button

doesn't make a difference the silkscreen "IC1" still shows up and is in the

way when I do the routing. Eagle won't let me smash the part to move it so

I guess I'll have to copy and create my own version.

You didn't say, do you know how close to the edge of the board I can have

silkscreen or parts when using the Pentalogix board service.

Just hide the tNames or bNames layer to not see the part names when you

are routing. I have never heard of being unable to smash a part, perhaps

you are doing it wrong? What is visible in the board editor is also not

related to the silkscreen, that happens when you make gerber files and

include drawing layers to your silkscreen file.

From the randomness of your posts, it sounds like you don't know what

you are doing. I would suggest that you do the eagle tutorial to

familiarize yourself with the program before asking any more questions -

  you don't know enough about the program to be able to even explain

things to you.