# ESP32-C3 BSP Introduction

[中文](README_ZH.md) | English

This document records the execution instruction of the BSP (board support package) for the [ESP32-C3](http://luatos.com/t/esp32c3) development board.

The document is covered in two parts:

- Board Resources Introduction
- Quickly Get Started

## Resources Introduction

We tested 2 development boards, it all works, but due to the different LED pins of the two development boards, so we'll need to select the corresponding development board in the menuconfig. 

- [LUATOS_ESP32C3](https://wiki.luatos.com/chips/esp32c3/board.html)

![LUATOS_ESP32C3](images/luatos_esp32c3.png)

- [HX-DK-商](https://docs.wireless-tech.cn/doc/7/)

![hongxu](images/hx_shang.png)

The mainly-used resources of LUATOS_ESP32C3 are shown as follows:

- MCU: [esp32-c3](https://www.espressif.com/sites/default/files/documentation/esp32-c3_datasheet_en.pdf)，Main Frequency 160MHz, 407.22 CoreMark; 2.55 CoreMark/MHz
- Built-in Chip: 384KB ROM, 400KB SRAM
- Peripherals
  - Red LED: 2, LED: D4 (IO12), D5（IO13）
  - Button: 2, K1（BOOT） K2(RST)
  - SPI FLASH: 4M
- Common-used interfaces: USB, UART, etc.

### For more details about this board, please refer to [Here](https://wiki.luatos.com/chips/esp32c3/board.html).

## **Peripheral Condition**

Each peripheral supporting condition for this BSP is as follows:

| **On-board Peripherals** | ****Support**** | ****Remark****                                               |
| ------------------------ | --------------- | ------------------------------------------------------------ |
| GPIO                     | Support         |                                                              |
| UART                     | Support         | Using LUATOS_ESP32C3 development board requires connecting serial port to USB chip UART0_TX and UART0_RX (such as CP2102) |
| JTAG debug               | Support         | ESP32C3 usb-linked development boards can be debugged        |
| WIFI | Partial support | There are currently some problems, such as `rt_mq_recive` cannot be used in ISR, etc. |
| BLE | Partially supported | There are currently some problems, such as `NimBLE` running errors after starting for a while |
| GDBStub | Support | You can use the GDB provided by ESP-IDF by turning on the `BSP_ENABLE_GDBSTUB` switch, which will enter GDB mode after a chip error |

Note:

1. WIFI and BLE cannot be enabled at the same time. When using the BLE driver, be sure to turn off the `RT_USING_WIFI` and `LWIP` switches in `menuconfig`. In addition, due to limited capabilities and lack of debugging equipment, there are problems with WIFI and BLE driver operation. If it can be solved, please contact [timwcx@qq.com](mailto:timwcx@qq.com).

2. The BLE driver only supports `NimBLE` and is provided by the `bluetooth` component in `esp-idf`. To use the BLE driver, please refer to `bsp/ESP32_C3/packages/ESP-IDF-latest/examples/bluetooth/nimble` Sample program, please note that the `esp_timer_init()` function must be called to initialize the clock driver before calling the `NimBLE` related interface.

One way to run the BLE sample is to add the sample program to `scons` compilation and call the clock initialization program and sample program entry in `bsp/ESP32_C3/main/main.c`.

```c
int main(void) {
   ...
#ifdef BSP_USING_BLE
     esp_timer_init(); //Call clock initialization program
     app_main(); //Call the BLE sample program entry
#endif
   ...
}
```

3、 Regarding the use of the GDBStub component, please see [ESP-IDF official documentation on GDBStub](https://docs.espressif.com/projects/esp-idf/zh_CN/latest/esp32c3/api-guides/tools/idf- monitor.html?#gdbstub-gdb), currently I have provided a debugging script `esp32c3.gdb`, the specific usage method is as follows.

```sh
wcx@tim  ~/rt-thread/bsp/ESP32_C3   esp32 ±  sudo riscv32-esp-elf-gdb # Enter gdb debugging
GNU gdb (crosstool-NG esp-2022r1-RC1) 9.2.90.20200913-git
Copyright (C) 2020 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "--host=x86_64-build_pc-linux-gnu --target=riscv32-esp-elf".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
    <http://www.gnu.org/software/gdb/documentation/>.

For help, type "help".
Type "apropos word" to search for commands related to "word".
(gdb) source esp32c3.gpb  # Load gdb script
0x3fca8c30 in __stack_start__ ()
(gdb) 
```

## Environment construction and compilation

1. Download the RISC-V toolchain:

     ```sh
     wget https://github.com/espressif/crosstool-NG/releases/download/esp-2022r1-RC1/riscv32-esp-elf-gcc11_2_0-esp-2022r1-RC1-linux-amd64.tar.xz
     tar xf riscv32-esp-elf-gcc11_2_0-esp-2022r1-RC1-linux-amd64.tar.xz
     ```

2. Configure the path of the toolchain:

     Add the local path of the `RISC-V` toolchain to the `EXEC_PATH` variable in the `rtconfig.py` file, or specify the path by setting the `RTT_EXEC_PATH` environment variable, for example:

     ```sh
     export RTT_EXEC_PATH=/opt/riscv32-esp-elf/bin
     ```

3. Compile

     Install esptool to convert ELF files to binary flash files:

     ```sh
     pip install esptool
     ```

     Execute the following command on the Linux platform to configure:

     ```
     scons --menuconfig
     ```

     It will automatically download env-related scripts to the `~/.env` directory, and then execute:

     ```sh
     source ~/.env/env.sh

     cd bsp/ESP32_C3/
     pkgs --update
     ```

     It will automatically download `RT-Thread-packages/esp-idf` and `RT-Thread-packages/FreeRTOS-Wrapper`, after updating the software packages, execute `scons` to compile the board support package.

     If the compilation is successful, `rtthread.elf`, `rtthread.bin` files will be generated.

## Download and program

1. Programming tool download

     The current bsp test uses the `flash_download_tool_3.9.4` tool to program without errors.

     Programming tool download address: [https://www.espressif.com.cn/sites/default/files/tools/flash_download_tool_3.9.4_0.zip](https://www.espressif.com.cn/sites/default/files/tools/flash_download_tool_3.9.4_0.zip)

2. Programming tool configuration

     Chip model selection `ESP32-C3`

     Configure the binary file and offset address as follows:

     | binary file | offset address |
     | ------------------- | -------- |
     | bootloader.bin | 0x0 |
     | partition-table.bin | 0x8000 |
     | rtthread.bin | 0x10000 |

     Among them, `bootloader.bin` and `partition-table.bin` can be found in the `bsp/ESP32_C3/builtin_imgs` folder. After the configuration is completed, the screenshot is as follows, and then click `START` to download.

     ![flash_download_tools](images/flash_download_tools.png)

## Notes

- The basic functions are now supported, but it needs more, welcome any contributions and feedback. 


Maintainer: 

- [supperthomas](https://github.com/supperthomas) email address: [78900636@qq.com](mailto:78900636@qq.com)
-  [tangzz98](https://github.com/tangzz98) email address: [tangz98@outlook.com](tangz98@outlook.com)

Special thanks to [chenyingchun0312](https://github.com/chenyingchun0312) for providing support on the RISC-V part working.