Hi Naveen!

Thanks for the fast response! You're correct, I'm using that API. I have checked the return code, and it is "noerror". Here is my code snippet:

    RetCode_t retcode;
    point_t p;
    
    p.x=400;
    p.y=240;
    
    lcd.foreground(RGB(255,255,0));

 

    lcd.SelectUserFont(BPG_Arial63x63);
    lcd.puts(10,10,"Boo!");


    retcode=lcd.circle(p, 100, BrightRed);
    //wait_us(11000);
    if (retcode==noerror)
    {
      retcode=lcd.circle(p, 50, BrightRed);
    }
    if (retcode!=noerror)
    {
        lcd.puts(10,30, "Error");
    }
    else
    {
        lcd.puts(10,30, "No error");
    }
    

When I run the code, I see the text "No error", but the large circle is only partially drawn (just a small part of it at the top of the circle). If I uncomment the wait_us line in the code above, then the circles are drawn fully complete, and I still see "No error" message. If I change the wait_us value to something less than 11000, for example 5000, then I see more of the large circle drawn compared to when the wait_us is fully commented out, but for it to be a full circle I need about 10msec (10000) to be used or higher.

I actually don't mind that the command completes before the circle is drawn. It gives the rest of my code more time to execute : ) But I have no way of knowing how long I should wait for, before issuing the next circle command. This is why I thought maybe there was some function I was supposed to call to check if the display is busy or something : ( Thanks,

Shabaz.

Hi Shabaz,

Please see if you can use the features provided in STSR register on RA8875.

https://cdn-shop.adafruit.com/datasheets/RA8875_DS_V19_Eng.pdf

The RA8875 library uses this register in method like _WaitWhileBusy() . https://os.mbed.com/users/WiredHome/code/RA8875_Demo/ doesn't use any callbacks. RA8875 class also sets the callbacks to NULL, hence it seems like callbacks are not really used.

Thanks, Naveen, team Mbed.

I ran a test starting with your code. My full main.cpp is shown here, using the online compiler and with an LPC1768. Note the revision numbers of the mbed-os and RA8875 library.

//
#include "mbed.h"           // mbed-os rev 4464
#include "RA8875.h"         // rev 154
#include "BPG_Arial63x63.h"

#define LCD_W 480           // Configured for 4 in screen
#define LCD_H 272
#define LCD_C 16
RA8875 lcd(p5, p6, p7, p12, NC, "tft");             //MOSI, MISO, SCK, /ChipSelect, /reset, name
LocalFileSystem local("local");                     // access to file system for printscreen
DigitalOut led1(LED1);

int main()
{
    RetCode_t retcode;
    point_t p = {350, 150};

    lcd.init(LCD_W, LCD_H, LCD_C);
    lcd.Backlight(0.5f);
    lcd.foreground(RGB(255,255,0));
    lcd.SelectUserFont(BPG_Arial63x63);
    lcd.puts(10,10,"Boo!");
    retcode=lcd.circle(p, 100, BrightRed);
    //wait_us(11000);
    if (retcode==noerror) {
        retcode=lcd.circle(p, 50, BrightRed);
    }
    lcd.SetTextCursor(10,80);
    if (retcode!=noerror) {
        lcd.printf("Error %s", lcd.GetErrorMessage(retcode));
    } else {
        lcd.puts("no Error");
    }
    retcode = lcd.PrintScreen(0,0,LCD_W,LCD_H,"/local/Circle.bmp");
    lcd.SetTextCursor(10,160);
    lcd.printf("BMP %d", retcode);
    while (true) {
        led1 = !led1;
        wait(0.5);
    }
}

Before I added the PrintScreen, I rebooted over and over, maybe 2 dozen times and I did not see what you reported. I am using a 480x272 display for this test, but it has the same controller.

Since the display is write-mostly, I wonder if your SPI - MISO pin is not connected. I don't think it would work at all w/o that, but perhaps...

If you think the MISO pin is properly connected, perhaps you need a a pull-up resistor on that pin.

Shabaz, if this helps you solve it, please accept the answer. If not, tell us more.

Hi David,

Thanks for invesigating! I accidentally missed seeing it earlier. I did test the commands to ensure I got back noerror, and also changed the SPI speed in case it was an issue there, and the SPI lines were about 6 incles long (unfortunately I couldn't make them shorter). I did check your code and compare to the datasheet, and to be honest I couldn't see what could be going wrong (like you, I suspected MISO issues but couldn't see how that could cause just that failure), so for now I've deliberately inserted short delays, and I'm hoping to retest after I've purchased a new display. The one I had used was intended for 5V operation, and I'd done the resistor surgery to get it to 3.3V, I'm confident I did that correctly, but there's no guarantee there wasn't an issue with the display - I couldn't get the resistive touch working, so there may well be issues with the single unit I have, so I'd like to purchase a new display to rule that out, and also with a hardware font chip so I can explore that. I also plan to have more accessible wiring to an oscilloscope so that I can more deeply explore with. Thanks again for responding, and also for your hard work creating the code - it really is excellent. I'll set your answer to 'accepted' if that is fine by you, and re-open if I can (or create a new question) if things don't work out with the new display.