LM4F120 Launchpad not showing up when USB cable plugged in

the LM4F120 Launchpad board has two usb-ports, did you use the top usb port (closest the the pwr-select switch) and then put the switch into DEBUG position?

I am experiencing the exact same issue:

-set LM4F120XL power select switch to DEBUG

-insert USB cable into DEBUG micro USB port

-plug USB cable into Windows 7 PC

-no device recognized (however the RGB quickstart application runs on the LM4F120XL (I feel like the multi-color LED is taunting me now)

I followed the README FIRST document as well as the ICDI driver installation document.  No change.

I tried all USB ports on my PC (6 rear and 2 front).  No change.

I tried a new USB cable.  No change.

I tried pressing the RESET switch on the LM4F120XL.  No change (other than the RGB quickstart application resetting).

I tried switching to DEVICE and then back to DEBUG.  No change.

I tried the DEVICE USB port as well.  No change.

I tried restarting the PC.  No change.

There has to be some sort of button combination that I'm missing (to utilize the device with ICDI).  Anyone have any ideas?

Actually, Thomas, after determining that my Launchpad board would only play on the rear USB ports, I diagnosed my front-side USB issue by taking my system cover off and finding a loose USB motherboard cable inside.

Funny part is that I know my usb ports work (they work with other devices)

Applaud your methodical approach - and detailed listing here.  I feel your pain.

Believe there have been reports of incomplete solder connections @ certain of the USB connectors.   You're surely bringing 5V and Gnd from the PC to your board - but unknown is the integrity of the USB signals.  Suggest that you "ohm out" any/all USB signal lines - from the cable end which plugs into the PC to the actual signal trace as it exits the launchpad connector - and makes it way to the MCU.  An open or short here - well explains your difficulty.

Another thought - surely someone nearby has an XP or Vista system - using the exact same cable (but different drivers) may prove useful to see if either of these work.  (will eliminate my earlier possibility)

Thanks for the quick response and the help! I'll have to wait until the morning to get to another pc. I'll try that first, then pull out the trusty ohm meter. I'll follow up here with results.

Update:

-Plugged in the LM4F120XL on a PC running Windows XP.  Not recognized.  

-Tried several USB ports on the PC.  Not recognized.

-Tried a PC running Linux.  Ran "lsusb" and "sudo lsusb" before and after inserting the LM4F120XL.  Not recognized.

-Next, I plan to utilize an ohm meter to test for continuity from the D+ and D- lines of the usb cable up to the debug LM4F120H5QR.

Update:

-Using an ohm meter (with continuity tone on), I tested continuity between the ICDI USB port D+ and U2 pin 44 as well as ICDI USB port D- to U2 pin 43.  Both connections showed continuity (approximately 0 ohm with continuity tone sounding).

I'm almost out of ideas.  Has anyone seen a list of LM4F120XL board button commands?  I'm I have a gut feeling that I'm just not pressing the correct button combination to get the device to an "ICDI mode".

Update:

-Also tested U2 pins 43 and 44 to ground and VDD (3.3V).  No continuity present between pins 43 or pin 44 to ground or VDD.

It appears that "Windows 8" is the real problem and that Windows 7 should work -- so...

Did you pull up the drivers on the device manager screen and delete the old USB drivers before attempting a re-install?

Tell it to delete the associated files as well.

If the associated COM port(s) is (are) still there at that point delete them as well.

Reboot -- (1)Then re-instal the drivers (software) -- (2)then plug in the Launchpad. (3)Then go through the procedure to do the install to the particular USB port...

Sometimes the install seems to go on forever -- but it does work... Be patient -- have a coffee, put your feet up if appears to be "hung up" -- sleep and dream of a south seas Island Paradise while you wait if it does start the install. I went for lunch -- then finally -- all was well -- as I recall. (But, I like long leisurely lunches...)

Test with LMFlash -- before you attempt to run CCS or other toolchains. Download the current MCU Flash memory contents save it -- and you could also  calculate the CRC on the board contents -- you do not have to upload to test.

I have used something similar to the Win8 procedure to install difficult drivers in the past -- so that would be my final option.

Despite assurances that connectors and cables were fine, I re-soldered all my connectors and changed cables after sorting out the above -- no more problems.

Inserting and re-inserting the cable will lift the USB Connector pads on the early boards -- use the slide switch to "re-boot" the MCU whenever possible. Remove and re-insert cable at board only when all else fails.

I am also assuming that you obtained the latest USB drivers -- via the LaunchPad page or the Training wiki or wherever...

Dave,

I can't get a single new device to show up in device manager when I plug in the launchpad.  There are no installed device drivers to delete or overwrite because the board isn't detected.  I also tried telling device manager to search/detect new hardware.  Nothing.  I even tried manually installing the drivers (the latest ones from TIs site) by right clicking the INF files and choosing install.  Windows wouldn't let me do this, complaining that the INF file doesn't support that method of installation.  I tried this with all INFs in the drivers folder.

I've tried this on 3 PCs (Windows 7, Windows XP, Linux).  The Windows 7 PC had Code Composer, LM Flash Programmer, and the drivers present on the machine prior to plugging in the device for the first time.  The other PCs did not have a single piece of TI software installed prior to plugging in the device.  Still nothing detected.  

I've tried letting the lauchpad site connected to the PC for 15 minutes.  Nothing.

I've tried carefully positioning the micro USB cable in the port, thinking it was an intermittent connection.  Nothing.

In LM Flash Programmer on the Windows 7 PC, I tried verifying flash contents to an inputted CRC32 value (entire flash).  Resulted in error message "Error unable to find a target".  I did this setting configuration to both manual configuration (ICDI eval board interface) as well as LM4F120 Launchpad.  No difference.

My issue is that I can't get a PC to recognize the launchpad.  I've verified electrically that each pin of the USB port traces down to the appropriate pin on U2.  I even plugged in the launchpad and tested that the VDD port was at 3.3V.  I also tested continuity between VDD and GND on U2 (thinking maybe the chip fried).  Everything came back normal.

This almost seems like a board with a working U1, but a DOA U2.

Have you checked xtal (Y5) and related bypass "Cs"?  (timing cntl for U2) 

Have you/friends/firm any other Stellaris - which you could try?

Agree -- you have done your homework -- when I order low-cost boards I always order two -- just for this reason -- and pray there are no "line" defects.

Order another or send it back is what I would do.

When it's this cheap -- I just order another -- doing the return thing spends a lot of money.

Each to their own...

But... before I forget -- I ran into this with one of the boards and did a manual driver install -- then it found the board -- but you are right -- the USB interface does have to respond.

I presume you have checked other machines?

I am also presuming this is your machine and you have admin rights -- and not a restricted high security account...

Did you measured tht voltale of your usb? Only one of mu usb ports could recognize my LM4F launchpad,and i measured the voltage an find that  the usb ports that could not recognize launchpad get a lower volatile (just about 4.5V ).



 Kevin Zhang 

hello sir

                    I'm getting the problem with LM4F120XL evalution board. When i connected the board to my laptop (WIN7) and tryied to program using LM flashprogrammer

The error is coming "Erroer :Unable to find the Target".PLZ someone hepl me