初始化电路中的DA14531模块

Apologies if this question has been asked before. We recently purchased a number of DA14531 modules to integrate into a BLE-using project. At present we're still at the investigation phase.

To investigate how the module works, I hooked it up to a STM32L552 microcontroller (MCU) as recommended in section 7 of the datasheet:

* J14 TX on DA14531 to LPUART1 RX pin on the MCU.

*DA14531上的J10 RX到MCU上的LPUART1 TX引脚。

* J12 RST on DA14531 to GPIO pin on the MCU, left floating for now.

I had naively assumed that the module would come pre-configured with Codeless AT commands from the manufacturer, but I am not getting any response to the simple "ATI" identification command off the module at either 57600bps or 115200bps.

Presumably I need to flash the module with the Codeless .hex file before it can be used. However, the module is already soldered in-circuit and connected to the MCU. And I don't currently have a development board to flash the module separately. Once we go to production we will want to flash and/or upgrade the module in-circuit rather than have to flash them separately before soldering in-place.

是否有某种方法可以使用上述引脚配置将模块置于引导加载程序模式？我在SDK中找到了代码“DA145xx\u SDK/6.0.14.1114/utilities/flash\u programmer”，它似乎是在模块上运行以执行引导加载的代码。基于这些信息，我可以很容易地编写自己的flash实用程序在STM32L552内部运行。代码似乎表明引导加载程序使用1线UART模式，为此，我可能需要重新排列一点到MCU的布线。我有内联电阻在电路中，所以重新排列电线应该不是一个大的戏剧，我们将在下一个原型修复电路板。

What is the sequence that I need to use to force the DA14531 module into its bootloader, whether the module is already flashed or not? Pull RST high and wait a bit? Toggle some other pin? It isn't clear to me from the documentation at the moment how to do this. A document describing the bootloading sequence would be very handy. I may have missed it while scanning, so sorry if I missed something obvious.

希望有一种方法可以做到这一点，从工厂新的DA14531模块。