SCI-TX doesnt work properly

I want to send the data calculated in my power electronics algorithm to serial port to log the data. Hovewer, I am very confused on how to correctly route the signals to SCI-TX block. Even this simple code wont send any proper data to UART. What am i doing wrong? Should i enable FIFO interrupts ? I even tried changing the Output X-BAR configurations. More interestingly, my original code works in LAUNCHXL-F280025C but not in my project card with the same mcu on it.

Answer 1

[goutham_vijapur]

Hi Kemal Tas,

I understand that you are facing issues with transmitting SCI data and reading it via UART using your custom board with TI F280025C, while the same code was working on LAUNCHXL-F280025C

With TI F28002x controlCARD (Version: E1) and MATLAB R2024a, I used the model you shared and except for adding additional package header and terminator to the transmitted data to distinguish it from other data on the channel, all other settings were right (Refer ‘Host_SCI_Rx.mp4’)

As per the board schematics, GPIO28 and GPIO29 are connected to the FTDI Chip for communication with Host PC (Refer ‘GPIO_SCI.jpg’, ‘SCI_UART_XDS100v2.jpg’ and ‘Pin_Breakout.jpg’)

Hence, in the model, out of all the GPIO pins available to be selected for SCI Tx and SCI Rx (Refer ‘SCI_Rx_Tx_Pins.jpg’), GPIO28 is chosen for SCI Rx and GPIO29 is chosen for SCI Tx (Refer ‘SCI_Block_And_ConfigurationSettings.jpg’)

So, I would suggest selecting SCI Tx and SCI Rx GPIO pins such that they are UART to USB compatible for your custom board. You may have to use an external FTDI USB to serial converter if a similar thing is unavailable on your custom board.

References:

• MathWorks example for Serial Communication Using SCI Blocks: https://mathworks.com/help/ti-c2000/ug/serial-communication-example.html
• Datasheet: https://www.ti.com/lit/ds/symlink/tms320f280025c.pdf
• Schematics: <C2000Ware_Install_Location>\C2000Ware_5_00_00_00\boards\controlCARDs\TMDSCNCD280025C\E1\MCU072E1(001)_Sch.PDF
• PinBreakOut: <C2000Ware_Install_Location>\C2000Ware_5_00_00_00\boards\controlCARDs\TMDSCNCD280025C\E1\TMDSCNCD280025C_E1_120cCARD_pinout.pdf

[Kemal Tas]

Hi Goutham Vijapur,

Thank you so much for your detailed reply. I have observed that,

Using app PuTTY, i can actually see data being transmitted to my computer. But it seems like it cannot be converted into a correct form of data, so the output of Host Serial Receive block is zero.

I am also unable to form an External Mode connection to hardware board(as i understand, i do not need to use the sci blocks in my code to form a connection in external mode), so i doubt this is an issue with the code.

In case you want to see, i have captured the signals from launchpad and custom board, respectively.

Even though the signal from launchpad seems noisy, the data is correctly being transmitted. Hovewer, we could not find a problem in the custom board either.

This is a part of the schematic for the FTDI emulator. Are we missing any pins?