Problem Program SAMD51 from UART1 (SERCOM3) - Metro M4 AirLift

[sergioxdev]

Hi Guys

I am testing the grand central meter,
i would like to program this chip from another uart input, other than native usb,
switching from usb to another uart via a pin.

Any info are accepted

[sergioxdev]

Hi Guys
I update you, doing research I found the following posts:

• SAMD51: UART support timing issues #22
• 3 bugs fixed. Only tested on samd51 #129

I am tested it a metro m4 airlift, because i want to update the SAMD51 via serial UART,

1. I made these changes to the uf2.h file
   // ------------------------------------------------ ---------
   #define USE_LOGS 0
   #define USE_ASSERT 0
   #define USE_FAT 0
   #define USE_INDEX_HTM 0
   #define USE_CDC 1
   #define USE_UART 1
   #define USE_HID 0
   #define USE_WEBUSB 0
   #define USE_MSC 1

#define USE_SINGLE_RESET 1

#define USE_HID_SERIAL 0
#define USE_HID_EXT 0
#define USE_HID_HANDOVER 0
#define USE_MSC_HANDOVER 0
#define USE_MSC_CHECKS 0
#define USE_CDC_TERMINAL 0
#define USE_DBG_MSC 0
// ------------------------------------------------ ---------

2. I connected a FT232R on the RX / TX pins of the metro

3. I try to send the same bytes as the BOSSA, "0x4e, 0x23, 0x56, 0x23", to start the boot programming

but I don't get any response
some suggestions, to understand where I'm wrong
Thanks in advance

[sergioxdev]

Hi Guys

I update you, doing some debugging I found the problem

uf2-samdx1/src/main.c

uf2-samdx1/src/main.c

Line 306 in 2fd0593

if (!main_b_cdc_enable && usart_sharp_received()) {

the problem is about usart_sharp_received ()

going backwards.

uf2-samdx1/src/usart_sam_ba.c

uf2-samdx1/src/usart_sam_ba.c

Line 170 in 2fd0593

if (usart_is_rx_ready()) {

the problem is about usart_is_rx_ready ()

going backwards.

uf2-samdx1/src/usart_sam_ba.c

Line 177 in 2fd0593

bool usart_is_rx_ready(void) {

the problem is here, however FT232R is connected with the RX / TX pins of the Metro,
I try to send "#" on the serial, but usart_is_rx_ready () always returns false;

I also tried always on main to send a byte on UART1 (SERCOM3) with:
usart_putc (1);
but it does not send anything

Any suggestions