Mbed OS 5的自定义开发板移植 - NRF51
嗯，真香，比Arduino不知高到哪里去了
前言
最开始看到Mbed OS5的时候没太在意，然而最近Nucleo买多了就变成了……
真香！
步骤
正好手头的BLE开发板就又开始痒痒，那就上咯
手头的NRF51开发板是微雪的NRF51822开发板，芯片型号为_AC，意即32KB SRAM+256KB Flash的型号。我们首先用Mbed CLI新建一个项目，起名叫nrf51_hello就好了。
mbed new nrf51_hello
会在当前目录创建工程目录，随便写一个main.cpp，包含main函数用来对付链接问题（（
#include <mbed.h>
DigitalOut led(LED1);
int main() {
while(true) {
led = !led;
wait(0.5);
}
}
嗯，点灯工程师。
于是我们来处理板子的问题。Mbed OS 5的大致结构如下
. ├── [3.5K] CONTRIBUTING.md ├── [ 254] DOXYGEN_FRONTPAGE.md ├── [ 73] Jenkinsfile ├── [8.9K] LICENSE ├── [2.5K] README.md ├── [4.0K] TESTS ├── [4.0K] TEST_APPS ├── [4.0K] UNITTESTS ├── [ 0] astyle-branch.out ├── [4.0K] cmsis ├── [4.0K] components ├── [4.0K] docs ├── [107K] doxyfile_options ├── [2.3K] doxygen_options.json ├── [4.0K] drivers ├── [4.0K] events ├── [4.0K] features ├── [4.0K] hal ├── [ 36K] logo.png ├── [2.9K] mbed.h ├── [4.0K] platform ├── [ 381] requirements.txt ├── [4.0K] rtos ├── [4.0K] targets └── [4.0K] tools 14 directories, 11 files
添加板子定义的时候，我们需要在如下几个部分添加相应的文件
targets/targets.json
targets.json记录了所有板子的型号和特性，也是Mbed CLI寻找编译对象的入口
我们在其中添加自己的板子信息（照着SoC差不多的板子抄过来即可）
diff --git a/targets/targets.json b/targets/targets.json
index 3d0c2bdf5..1dc765096 100755
--- a/targets/targets.json
+++ b/targets/targets.json
@@ -2709,6 +2709,24 @@
"extra_labels_add": ["DELTA_DFCM_NNN50"],
"macros_add": ["TARGET_DELTA_DFCM_NNN50"]
},
+ "WAVESHARE_NRF51822": {
+ "supported_form_factors": ["ARDUINO"],
+ "inherits": ["MCU_NRF51_32K_UNIFIED"],
+ "device_has": ["USTICKER", "LPTICKER", "ANALOGIN", "I2C", "I2C_ASYNCH", "INTERRUPTIN", "PORTIN", "PORTINOUT", "PORTOUT", "PWMOUT", "SERIAL", "SERIAL_ASYNCH", "SERIAL_FC", "SLEEP", "SPI", "SPI_ASYNCH", "SPISLAVE"],
+ "device_name": "nRF51822_xxAC"
+ },
+ "WAVESHARE_NRF51822_BOOT": {
+ "supported_form_factors": ["ARDUINO"],
+ "inherits": ["MCU_NRF51_32K_BOOT"],
+ "extra_labels_add": ["WAVESHARE_NRF51822"],
+ "macros_add": ["TARGET_WAVESHARE_NRF51822"]
+ },
+ "WAVESHARE_NRF51822_OTA": {
+ "supported_form_factors": ["ARDUINO"],
+ "inherits": ["MCU_NRF51_32K_OTA"],
+ "extra_labels_add": ["WAVESHARE_NRF51822"],
+ "macros_add": ["TARGET_WAVESHARE_NRF51822"]
+ },
"NRF51_DK_LEGACY": {
"supported_form_factors": ["ARDUINO"],
"inherits": ["MCU_NRF51_32K"],
可以看出我们的板子叫做 WAVESHARE_NRF51822 。
2. Target定义文件，上述的 inherits 已经给定了这个板子所属的厂商和型号，在对应目录里添加相应定义文件，包含引脚定义 PinNames.h 和设备定义 device.h 。根据板子的外设和引脚信息修改对应文件即可。我们正在添加的板子应位于
targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF51/TARGET_MCU_NRF51822_UNIFIED/TARGET_WAVESHARE_NRF51822 中。
*** ../TARGET_NRF51_DK/PinNames.h 2018-10-27 12:42:18.034690786 +0800
--- PinNames.h 2018-10-27 13:43:22.036980344 +0800
***************
*** 120,134 ****
P0_29 = p29,
P0_30 = p30,
! LED1 = p21,
! LED2 = p22,
! LED3 = p23,
! LED4 = p24,
! BUTTON1 = p17,
! BUTTON2 = p18,
! BUTTON3 = p19,
! BUTTON4 = p20,
RX_PIN_NUMBER = p11,
TX_PIN_NUMBER = p9,
--- 120,132 ----
P0_29 = p29,
P0_30 = p30,
! LED1 = p18,
! LED2 = p19,
! LED3 = p20,
! LED4 = p21,
! BUTTON1 = p16,
! BUTTON2 = p17,
RX_PIN_NUMBER = p11,
TX_PIN_NUMBER = p9,
本例中 device.h 无需修改。
添加完板子定义我们来简单测试一下
imi415@imi415 ..ts/Hardwares/Mbed_Projects/nrf51_hello (git)-[master] % mbed compile -m WAVESHARE_NRF51822 -t GCC_ARM -j8
...
Compile [ 99.5%]: gpio_api.c Compile [ 99.6%]: qspi_api.c Compile [ 99.7%]: port_api.c Compile [ 99.9%]: rtc_api.c Compile [100.0%]: us_ticker.c Link: nrf51_hello Elf2Bin: nrf51_hello | Module | .text | .data | .bss | |--------------------|------------|----------|----------| | [fill] | 171(+4) | 19(+0) | 55(+0) | | [lib]/c.a | 22739(+0) | 2472(+0) | 56(+0) | | [lib]/gcc.a | 7142(+0) | 0(+0) | 0(+0) | | [lib]/misc | 208(+0) | 12(+0) | 25(+0) | | [lib]/stdc++.a | 1(+0) | 0(+0) | 0(+0) | | main.o | 2229(+7) | 5(+0) | 97(+0) | | mbed-os/components | 54(+0) | 0(+0) | 0(+0) | | mbed-os/drivers | 787(+16) | 0(+0) | 0(+0) | | mbed-os/events | 1240(+0) | 0(+0) | 0(+0) | | mbed-os/features | 40015(+6) | 4(+0) | 1334(+0) | | mbed-os/hal | 1758(-2) | 8(+0) | 130(+0) | | mbed-os/platform | 3898(-4) | 260(+0) | 221(+0) | | mbed-os/rtos | 10287(-2) | 168(+0) | 6113(+0) | | mbed-os/targets | 9281(-3) | 20(+0) | 865(+0) | | Subtotals | 99810(+22) | 2968(+0) | 8896(+0) | Total Static RAM memory (data + bss): 11864(+0) bytes Total Flash memory (text + data): 102778(+22) bytes Image: ./BUILD/WAVESHARE_NRF51822/GCC_ARM/nrf51_hello.hex mbed compile -m WAVESHARE_NRF51822 -t GCC_ARM -j8 146.18s user 37.11s system 536% cpu 34.191 total imi415@imi415 ..ts/Hardwares/Mbed_Projects/nrf51_hello (git)-[master] %
我们就可以在生成目录 BUILD/ 下找到ELF和IHEX文件了。
NRF51需要一个闭源静态库用来实现驱动和蓝牙，Nordic管他叫SoftDevice。我们首先需要下载SoftDevice到设备。
本例中依然使用OpenOCD，调试器使用LPC11U35开发板运行DAPLink（CMSIS-DAP）固件，制作方法后述。
运行
openocd -f /usr/share/openocd/scripts/interface/cmsis-dap.cfg -f /usr/share/openocd/scripts/target/nrf51.cfg
Open On-Chip Debugger 0.10.0+dev-00523-g2a3b709aa (2018-08-30-22:25) Licensed under GNU GPL v2 For bug reports, read http://openocd.org/doc/doxygen/bugs.html Info : auto-selecting first available session transport "swd". To override use 'transport select <transport>'. cortex_m reset_config sysresetreq adapter speed: 1000 kHz Info : Listening on port 6666 for tcl connections Info : Listening on port 4444 for telnet connections Info : CMSIS-DAP: SWD Supported Info : CMSIS-DAP: FW Version = 1.10 Info : CMSIS-DAP: Interface Initialised (SWD) Info : SWCLK/TCK = 1 SWDIO/TMS = 1 TDI = 0 TDO = 0 nTRST = 0 nRESET = 1 Info : CMSIS-DAP: Interface ready Info : clock speed 1000 kHz Info : SWD DPIDR 0x0bb11477 Info : nrf51.cpu: hardware has 4 breakpoints, 2 watchpoints Info : Listening on port 3333 for gdb connections
一如既往，显示连接成功。
运行 telnet localhost 4444 连接到OpenOCD的CLI界面，运行
reset init halt CPU，接着运行
flash write_image erase /path/to/softdevice/s130.hex 下载SoftDevice到设备。
最后运行
flash write_image erase /path/to/nrf51_hello.elf 下载应用程序到设备，执行 reset 即可点灯成功（
おまけ
P.S. NRF51822 的串口默认流控，请确认CTS/RTS pin连接正常，否则串口会卡死目标板。
我们来运行一下Mbed OS的心率传感器示例
由于之前已经下载过SoftDevice，本次无需重新下载。直接下载应用程序到设备即可。
通过Nordic的BLE App，就可以看到心率了…… 170了，我要挂了.jpg