Spy By Wire with the LaunchPad...

Started by "Dan...@lakeweb.net [msp430]" June 29, 2017
About a year ago I made this stepper controller for my son's rotary
table on his mill. I used the FET430UIF at the time as I've been lead to
believe that wires to an off board chip from a launchpad just would not
work. FET debugging with the FET430 was a real pain as I could not set
more than one break point at a time with an MSP430G... chip. So this
time around I figured I would try the launch pad. It was iffy, once it
worked with 3" leads. Then I put the chip on the launch pad and used
jumpers to the target project. Then I started having strange problems,
like the display would crash but the chip would still debug. So I
grabbed a scope probe to see what the display data and clock looked
like. It just started working flawlessly. The light in my head finally
came on.

My 10 volt supply to the target was floating, I've always worked like
that. The scope has a hard bench ground. With the scope ground connected
I could not get it to fail.

So I pulled all those annoying wired from the launch pad to the target,
put the chip back in the target, and hooked up 6" wires to just RST,
TEST, and ground. It works flawlessly, again. The real problem was
depending on the USB ground for the signals to the target. using the
scope without its ground confirmed that the signals from the launch pad
where 'soft' if you will. With a bench ground to the the target the
signals were beautiful. At that, the spy by clock is not that fast,
700ns to transfer.



I've added a DIR switch and cleaned up the motor power end and put that
in a box.

Best, Dan.


Posted by: Dan Bloomquist



Beginning Microcontrollers with the MSP430

Dan,
Grounds are Important

.

.

.

.

.

and

.

.

.

.

.

.

Magical.
Emmett Redd Ph.D. mailto:E...@missouristate.edu
Professor (417)836-5221
Department of Physics, Astronomy, and Materials Science
Missouri State University Fax (417)836-6226
901 SOUTH NATIONAL
SPRINGFIELD, MO 65897 USA Dept (417)836-5131

In statesmanship get the formalities right, never mind about the moralities. -- Mark Twain.
________________________________
From: m... on behalf of Dan Bloomquist y...@lakeweb.net [msp430]
Sent: Thursday, June 29, 2017 1:19 PM
To: MSP430YahooGroup
Subject: [msp430] Spy By Wire with the LaunchPad...

About a year ago I made this stepper controller for my son's rotary
table on his mill. I used the FET430UIF at the time as I've been lead to
believe that wires to an off board chip from a launchpad just would not
work. FET debugging with the FET430 was a real pain as I could not set
more than one break point at a time with an MSP430G... chip. So this
time around I figured I would try the launch pad. It was iffy, once it
worked with 3" leads. Then I put the chip on the launch pad and used
jumpers to the target project. Then I started having strange problems,
like the display would crash but the chip would still debug. So I
grabbed a scope probe to see what the display data and clock looked
like. It just started working flawlessly. The light in my head finally
came on.

My 10 volt supply to the target was floating, I've always worked like
that. The scope has a hard bench ground. With the scope ground connected
I could not get it to fail.

So I pulled all those annoying wired from the launch pad to the target,
put the chip back in the target, and hooked up 6" wires to just RST,
TEST, and ground. It works flawlessly, again. The real problem was
depending on the USB ground for the signals to the target. using the
scope without its ground confirmed that the signals from the launch pad
where 'soft' if you will. With a bench ground to the the target the
signals were beautiful. At that, the spy by clock is not that fast,
700ns to transfer.


[http://lakeweb.net/CNC/images/rotary_control.jpg]

>

I've added a DIR switch and cleaned up the motor power end and put that
in a box.

Best, Dan.


Posted by: Dan Bloomquist



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Whoever told you that wires from a launchpad wouldn't work mislead you
badly. It is basically what they are designed for. They have expansion
connectors to add on boards, these are just short wires really. I'm also
totally unsurprised that you had problems scoping the signals without
connecting your scope and board grounds. Sometimes, if you forget this,
you can even see tiny sparks as you try to hook your scope probe to the
board.

Glad you sorted things.

Al

On 30/06/2017 3:49 AM, Dan Bloomquist y...@lakeweb.net [msp430] wrote:
> About a year ago I made this stepper controller for my son's rotary
> table on his mill. I used the FET430UIF at the time as I've been lead to
> believe that wires to an off board chip from a launchpad just would not
> work. FET debugging with the FET430 was a real pain as I could not set
> more than one break point at a time with an MSP430G... chip. So this
> time around I figured I would try the launch pad. It was iffy, once it
> worked with 3" leads. Then I put the chip on the launch pad and used
> jumpers to the target project. Then I started having strange problems,
> like the display would crash but the chip would still debug. So I
> grabbed a scope probe to see what the display data and clock looked
> like. It just started working flawlessly. The light in my head finally
> came on.
>
> My 10 volt supply to the target was floating, I've always worked like
> that. The scope has a hard bench ground. With the scope ground connected
> I could not get it to fail.
>
> So I pulled all those annoying wired from the launch pad to the target,
> put the chip back in the target, and hooked up 6" wires to just RST,
> TEST, and ground. It works flawlessly, again. The real problem was
> depending on the USB ground for the signals to the target. using the
> scope without its ground confirmed that the signals from the launch pad
> where 'soft' if you will. With a bench ground to the the target the
> signals were beautiful. At that, the spy by clock is not that fast,
> 700ns to transfer.
>
> I've added a DIR switch and cleaned up the motor power end and put that
> in a box.
>
> Best, Dan.
>
>
> Posted by: Dan Bloomquist
>
>
>
> Yahoo Groups Links