TMS320F28035: CCS/TMS320F28035: SCI echoback example not working

Thank you Marylin,

I have tried as suggested:

1. RS-232 PIN 2 connected to Rx.
2. RS-232 PIN 3 connected to Tx
3. RS-232 PIN 5 connected to GND
4. SW1 is on ON - default was off (?) and switched position. 
5. J9 is still shorted, as seen below.

But I still did not see anything on terminal using the correct port settings, not in a serial port monitor application. 

Thanks,
Robin

Hi Robin,

I am able to duplicate the issue on my side as well. I will need some time to look into this and figure out what the correct implementation is.

SCI communication through the built-in FTDI module should still work if you are able to connect the controlCARD to your pc via the docking station. If you do this, switch SW1 to the off position and make sure J9 is shorted. 

Best Reagrds,

Marlyn

Hi Marylin,

Not sure how to do use SCI via the built-in FTDI module, because the docking station is connected to the PC via the USB. This generates a COM port that is consumed by the JTAG debugger. So, Ițm assuming that some connector needs to be connected somewhere, but where?

Sorry, so many questions...

Thanks,

Robin

Hi Robin,

All you need is the cable that connects from the docking station to your PC, like so:

Within device manager on your computer you will see the port that needs to be used (in the example below it is COM12):

Ensure that switch SW1 to the off position and J9 is shorted.

This is a good example that will work in this case: 

C:\ti\c2000\C2000Ware_version\device_support\f2803x\examples\c28\sci_echoback

You can open a putty terminal with the correct settings and the COM port you see in the device manager window.

Please let me know if you have any questions.

Best Regards,

Marlyn

Hi Marylin,

I've tried with the new configuration, to no avail. 

1. The program is running.

2. The debug probe driver is installed, tests are successful.

3. The correct device is selected as a target.

4. No welcome message from the program, despite the fact that the serial terminal is connected to the correct device.

Of course:

* SW1 is in OFF.

* JP9 is shorted.

Thanks,

Robin

Hi Robin,

Do you have another machine you could try with a newer version of C2000Ware and CCS? 

On my end, the target configuration I used was for the actual part not the Experimenter Kit. I don't believe this is the root cause for your issue but may be worth a try. 

Can you please attach a screenshot of your device manager showing the com port as well as a picture of the hardware setup? 

Best Regards,

Marlyn

Hi Marylin,

Sure thing, previously, I was in a virtual machine powered by VMWare player, but I am setting up a physical device and try again. 

Will update, once  have some results. 

I have also ordered a new Experimenter's Kit, in case the one I have has hiccups.

Thanks,
Robin

Hi Marylin, 

I have some updates.

In Windows XP x64 SP2:

1.1. CCS7 fails to install altogether.
1.2. In CCS6, the newest version of the C2000 compiler is 20.2.6 and the sample that you've suggested, in C2000Ware v4, requires version 21.6, so I coul not get it to work.
1.3. In CCS6, the newest version of the C2000 compiler is 20.2.6 and the sample that you've suggested, in C2000Ware v3, requires version 20.2, so it should work, but it kept complaining about the version, as it did not recognize the version under Preferences > CCS > Build > Compiler (but it was installed).
1.4. In CCS6 with C2000Ware v2, the code builds, and there IS an echo on the XDS probe COM port.

So, what this means is that the following configuration worked:

1. SW1 in OFF
2. JP9 shorted.
3. Only the code in C2000Ware version 2 worked with my Experimenter's Kit (R3).

I have also tried with SW1 in ON and JP9 shorted - as the docs said it would enable the RS-232 communication that I need, but I could NOT get an echo. 

Maybe the above help facilitate the required debugging, and help solve my initial problem, with the RS-32 communication?

Please advise.

Thanks,
Robin

Hi Robin,

I am glad you were able to get the SCI communication working on your current setup.

Robin Molnar said:

I have also tried with SW1 in ON and JP9 shorted - as the docs said it would enable the RS-232 communication that I need, but I could NOT get an echo. 

Maybe the above help facilitate the required debugging, and help solve my initial problem, with the RS-32 communication?

I see the same issue as you as well. I am still trying to debug where the issue might be. This is one of our older hardware platforms so resources are limited. I will post an update once I am able to make some progress with this.

Best Regards,
Marlyn

Hi Marylin,

Regarding "This is one of our older hardware platforms so resources are limited.", the Experimenter's Kit that I have is brand new, ordered just this year, and I will also investigate this (because I really need this to work).

Will also post an update, once I have one.

Thanks so much!

Robin

Hi Robin,

Robin Molnar said:

the Experimenter's Kit that I have is brand new, ordered just this year

My apologies, I did not mean to imply your experimenter kit was not new. I meant this set of hardware was released many years back. It is not something TI newly designed. 

Best Regards,

Marlyn

Hi Marylin, 

Understood. 

Today I have tried with a new Experimenter's Kit, in the default configuration. On the COM port associated with the XDS100 probe, I managed to receive the text, but I was unable to send (or, the device was unable to receive), although J9 was shorted.

Will keep investigating.

Thanks,
Robin

Hi Robin,

Robin Molnar said:

On the COM port associated with the XDS100 probe, I managed to receive the text, but I was unable to send (or, the device was unable to receive), although J9 was shorted

What position is SW1 in?

Could you please try to run the sci_loopback example and verify that with SW1 in the ON position, J9 shorted, and then the RX ISO/TX ISO pins connected you are able to see communication? The only change needed in the example is disabling the internal loopback:

	//SciaRegs.SCICCR.bit.LOOPBKENA =1;       // Enable loop back
    SciaRegs.SCICCR.bit.LOOPBKENA =0;       

Also, what is your connection like for the RS-232? In the attached pictures I can see the connection you have with the docking station but not to what that is being connected to.

Best Regards,

Marlyn

Hi Marylin,

The results are mixed. 

I will use your picture to explain. 

1. I managed to get an echo on the COM port of the XDS probe, but only with C2000Ware v2. 
2. Seeing that the code works, I've switched JP1 to ON, JP9 shorted, and I have connected an Alten UC232A USB to RS-232 adapter. But I could not get an echo.

From your proposal above, I take it that you want me to connect Rx to Tx , disable the internal loopback and see if the works, correct?

Thanks,
Robin

Hi Robin,

Robin Molnar said:

1. I managed to get an echo on the COM port of the XDS probe, but only with C2000Ware v2.

I am not sure why version 1 does not work, but at least version 2 does. We have version 4.01 now.

Robin Molnar said:

From your proposal above, I take it that you want me to connect Rx to Tx , disable the internal loopback and see if the works, correct?

Yes, the idea is to verify that the communication does indeed make it out to the RX and TX pins and the issue is what is happening somewhere beyond this point.

Best Regards,

Marlyn

Hi Robin,

Robin Molnar said:

Where is this "    SciaRegs.SCICCR.bit.LOOPBKENA =0;       " from? Which file/ line?

I don't know if this example exists in the version you have of C2000Ware. In the latest version, the example is located in:

C:\ti\c2000\C2000Ware_version\device_support\f2803x\examples\c28\scia_loopback

Robin Molnar said:

2. If I do (1), how will I send/ receive data to the device? The COM port of the XDS probe I know works, the docking station's RS-232 bit I have troubles with.

The example is a loopback test which means it transmits data and then expects the same data to be received. This is why I asked if you could please connect the RX and TX pins together so that we can test that the hardware works and data is making it out to the pins. Using the build-in JTAG we can read the data that is being sent and received within the example. Again, the purpose of all of this is to ensure data is able to propagate to the ISO-TX pin and then received from the RX-ISO pin. Please ensure SW1 is in the ON position for this test, enabling the ISO-TX and ISO-RX connection. 

Best Regards,

Marlyn

Hi Marylin,

With:

1. Tx connected to Rx
2. SW 1 in ON
3. JP9 shorted
4. SciaRegs.SCICCR.bit.LOOPBKENA =0;  

I seem to be getting something, as seen below.



To me, this means that the hardware is OK, so the problem most likely is software.

Is my understanding wrong?

Thanks,
Robin

Hi Robin,

I am glad you were able to get that test working. 

Robin Molnar said:

To me, this means that the hardware is OK, so the problem most likely is software.

Yes, this shows that the hardware is okay and data is indeed making it to the pins. Can you expand on what software you are referring to? 

I think there needs to be more debug on the part that happens after the C2000 device/docking station. 

Best Regards,

Marlyn

Hi Marylin,

I have managed to get the RS-232 communication working. 

After confirming, using the loopback example above, that the HW is OK, and that the SW is OK (it does transmit), I've proceeded to test the RS-232 adapter and the wiring.

The mistake that I did was: 

* I wired Rx pin on the docking station to the Rx pin of the DB9 connector (pin 2)
* I wired Tx pin on the docking station to the Tx pin of the DB9 connector (pin 3).

How I made it work:
* I wired Rx pin on the docking station to the Tx pin of the DB9 connector (pin 3)
* I wired Tx pin on the docking station to the Rx pin of the DB9 connector (pin 2)

Of course:
* SW 1 is ON (RS-232 is enabled)
* JP9 is shorted.

Thanks so much for helping me debug this, and resolving my communications problem.

Robin

P.S. The source code clearly states how to do the wiring, not sure how I've missed this. :(

Hi Robin,

No worries, I am glad you were able to get it working and can continue on your project. Best of luck!

Best Regards,

Marlyn