【NRF52840】Learning Record

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【NRF52840】Learning Record [Copy link]

• 【NRF52840】Learning Record

1. Introduction

I recently bought an NRF52840 DK development board and plan to learn some knowledge about Bluetooth. Here is a record of the learning process

2. Chip Introduction

For some information about the NRF52840 chip, you can check it on the official website: nRF52840

3.Bluetooth Engineering Package SDK

Download the relevant SDK package from the official website: https://www.nordicsemi.com/Products/nRF52840/Compatible-downloads?lang=zh-CN

For some introduction to the SDK package, you can refer to this blog: Getting Started with nrf52840 Chip

4. Bluetooth protocol stack sample analysis

There are many routines in the downloaded SDK package. Here we analyze the Bluetooth protocol stack sample. The path is nRF5_SDK_17.1.0_ddde560\examples\ble_peripheral\ble_app_template. For more analysis, you can refer to this blog post: nrf52840 Bluetooth protocol stack sample analysis . I will add some

①Log printing initialization

Enter the log_init() function:

We can see the macro definition of NRF_LOG_LFCLK_FREQ, whose value is 32768. Therefore, when we want to use the log function, there must be a 32.768kHz crystal oscillator on the hardware to complete the corresponding initialization.

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Then, find the UART related initialization related to the log, we can find that it uses UAERT0, the TX pin is P0.06, the RX function is not used, and the baud rate is 115200.

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② Protocol stack default configuration settings

Entering the protocol stack configuration function, we find that the sd_ble_cfg_set function is actually used to configure the protocol stack. According to the comments on it, we can find two points: we can call this function to configure the protocol stack anywhere where sd_softdevice_enable is enabled but sd_ble_enable is not enabled; the amount of memory allocated to SoftDevice by app_ram_base should be large enough.

Where the parameter cfg_id is the enumeration BLE_CONN_CFGS, BLE_COMMON_CFGS, BLE_GAP_CFGS or BLE_GATTS_CFGS.

③GAP initialization

There are several types of safe mode configurations:

④ Broadcast initialization

The broadcast name is shown as ble_advdata_name_type_t enumeration.

Broadcast logo

⑤ Update connection parameters

The connection parameter ble_conn_params_init_t structure is

lkh747566933

This is the first time I have heard of this product. I would like to join in the fun and take a look at the learning notes of the OP.

lkh747566933

Good information, thanks for sharing it. It's a good opportunity to learn from other people's designs.