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LAUNCHXL-CC1350: BOOSTXL-SHARP128 doesn't work.

Part Number: LAUNCHXL-CC1350
Other Parts Discussed in Thread: BOOSTXL-SHARP128, CC1350, , CC1352R

Hello,

I've got a question regarding the CC1350 Launchpad in combination with the BOOSTXL-Sharp128 LCD-shield. If I load the demo from Resoure-Explorer/examples/display (SDK-version: simplelink_cc13x0_sdk_4_10_01_01) the LCD just shows random points:

I've plugged in a logic analyzer to see the signals on the spi-bus and LCD-pins. It seems like data is sent but, the display doesn't do anything:

I have no idea what I'm doing wrong. Does anyone have an idea how to solve this problem?

Thank you very much!

  • I have seen random data on the display when running an example that is not using the LCD.

    - The DIsplay example shuld also print the same text on the UART. Do you get data here?

  • Yes the UART output works fine at the same time. Do I have to deactivate it to get the lcd running? I think it should work both at the same time?

  • As I know, either one of LCD or UART would work. You have to switch UART to use LCD.

  • Please see the code:

            /* Print to LCD and clear alternate lines if the LED is on or not. */
            Display_clearLine(hLcd, ledPinValue ? 1 : 0);
            Display_printf(hLcd, ledPinValue ? 0 : 1, 0, "LED: %s",
                    (ledPinValue == Board_GPIO_LED_ON) ? "On!":"Off!");
    
            /* Print to UART */
            Display_clearLine(hSerial, ledPinValue ? 1 : 0);
            Display_printf(hSerial, ledPinValue ? 0 : 1, 0, "LED: %s",
                    (ledPinValue == Board_GPIO_LED_ON) ? serialLedOn : serialLedOff);

    as can be seen the example write to both the LCD and the UART. But please double check that BOARD_DISPLAY_USE_LCD is set. Also try to step through the code to see what the code is doing.

    The LCD booster pack you are using is not fully mechanical stable, the small flat cable between the driver and the physical display have an issue with poor connection. It could be something like this you are experiencing.  

  • I double checked the predefined symbols and BOARD_DISPLAY_USE_LCD is definitely set. I stepped through the code and hLcd is found, for example in this section:

        /* Check if the selected Display type was found and successfully opened */
        if (hLcd) {
            Display_printf(hLcd, 5, 3, "Hello LCD!");

    Unfortunately the display doesn't do anything. Now it stays black and looks like its not doing anything. I have also bought a spare one, because you said it could be a problem with the mechanical connection. But the problem still exists.

    I didn't change anything on the example code. Just plugged it in uploaded the code and nothing except the UART output happens.

  • For your reference, I test default display example without any modification under simplelink_cc13x0_sdk_4_10_01_01\examples\rtos\CC1350_LAUNCHXL\drivers\ and I can see both LCD and UART display "LED on" and "LED off' periodically. I would suggest you to remove your SDK and reinstall it to test from scratch again.

  • As YK pointed out, the code example should work out of the box. When you see "snow" on the display it indicates that the display is not getting the correct commands or similar. 

    Do you have a different Launchpad you also can test this example?

    I assume that you don't see any difference if you remove the connections to the logic analyzer? 

  • I bought another launchpad (CC1352R1 dev kit) and now it works right out of the box. This means its not a hadware error. What could be the reason for this? Maybe a bug within the examples for the CC1350?

  • Since I can make it work with out-of-box examples on LAUNCHXL-CC1350, I don’t think this a SW bug?

  • It could be that you have a hardware issue with your CC1350 LP?

    Have you compared the SPI traffic (bit by bit) when you use CC1350 LP and the CC1352R LP?