BetaFlight统一硬件配置文件研读之timer命令

统一硬件配置文件的设计是一种非常好的设计模式，可以将硬件和软件的工作进行解耦。

1. 源由

cli命令中timer是对硬件引脚和timer资源进行绑定的一个操作，主要用于以下设备：

• 电机
• PPM接收机
• LED灯带
• 伺服器

2. 代码分析

cliTimer
 ├──> "timer"
 │   └──> printTimer(DUMP_MASTER, NULL); return
 ├──> "timer list"
 │   └──> "NOT IMPLEMENTED YET"
 ├──>  "timer map"
 │   └──> showTimerMap(); return
 ├──> "timer show"
 │   └──> showTimers(); return
 ├──>  error return //边界检查
 ├──>  error return //有效性检查
 ├──> [find existing entry, or go for next available] error return //如果entry满，失败
 ├──>  printTimerDetails(ioTag, timerIOConfig(timerIOIndex)->index, false, DUMP_MASTER, cliDumpPrintLinef); return
 └──>  
     ├──> "list"
     │   ├──> for (unsigned index = 0; (timer = timerGetByTagAndIndex(ioTag, index + 1)); index++) 
     │   ├──> cliPrintLinef("# AF%d: TIM%d CH%d%s", timer->alternateFunction, timerGetTIMNumber(timer->tim), CC_INDEX_FROM_CHANNEL(timer->channel) + 1,timer->output & TIMER_OUTPUT_N_CHANNEL ? "N" : "");
     │   └──> return
     ├──> "none"
     │   └──> timerIndex = TIMER_INDEX_UNDEFINED;
     ├──> "af"
     │   ├──> for (unsigned index = 0; (timer = timerGetByTagAndIndex(ioTag, index + 1)); index++)
     │   ├──> for (unsigned index = 0; (timer = timerGetByTagAndIndex(ioTag, index + 1)); index++)
     │   └──> alternateFunction == alternateFunction> timerIndex = index;
     ├──> [assign new io timer]
     │   ├──> int oldTimerIndex = isExistingTimerOpt ? timerIOConfig(timerIOIndex)->index - 1 : -1;
     │   ├──> timerIOConfigMutable(timerIOIndex)->ioTag = timerIndex == TIMER_INDEX_UNDEFINED ? IO_TAG_NONE : ioTag;
     │   ├──> timerIOConfigMutable(timerIOIndex)->index = timerIndex + 1;
     │   └──> timerIOConfigMutable(timerIOIndex)->dmaopt = DMA_OPT_UNUSED;
     ├──> 
     │   └──> cliPrintLinef("# timer %c%02d: no change: %s", IO_GPIOPortIdxByTag(ioTag) + 'A', IO_GPIOPinIdxByTag(ioTag), orgvalString)
     └──> 
         └──> cliPrintLinef("# timer %c%02d: changed from %s to %s", IO_GPIOPortIdxByTag(ioTag) + 'A', IO_GPIOPinIdxByTag(ioTag), orgvalString, optvalString);

3. 实例分析

# timer
timer A10 AF1
# pin A10: TIM1 CH3 (AF1)
timer B00 AF2
# pin B00: TIM3 CH3 (AF2)
timer B01 AF2
# pin B01: TIM3 CH4 (AF2)
timer A00 AF2
# pin A00: TIM5 CH1 (AF2)
timer A01 AF2
# pin A01: TIM5 CH2 (AF2)
timer A02 AF2
# pin A02: TIM5 CH3 (AF2)
timer A03 AF2
# pin A03: TIM5 CH4 (AF2)
timer D12 AF2
# pin D12: TIM4 CH1 (AF2)
timer D13 AF2
# pin D13: TIM4 CH2 (AF2)
timer D14 AF2
# pin D14: TIM4 CH3 (AF2)
timer D15 AF2
# pin D15: TIM4 CH4 (AF2)
timer E05 AF4
# pin E05: TIM15 CH1 (AF4)
timer E06 AF4
# pin E06: TIM15 CH2 (AF4)
timer A08 AF1
# pin A08: TIM1 CH1 (AF1)

4. 配置情况

# help timer
timer - show/set timers
	<> | <pin> list | <pin> [af<alternate function>|none|<option(deprecated)>] | list | show

4.1 AFn配置查表

4.2 timer

# timer
timer A10 AF1
# pin A10: TIM1 CH3 (AF1)
timer B00 AF2
# pin B00: TIM3 CH3 (AF2)
timer B01 AF2
# pin B01: TIM3 CH4 (AF2)
timer A00 AF2
# pin A00: TIM5 CH1 (AF2)
timer A01 AF2
# pin A01: TIM5 CH2 (AF2)
timer A02 AF2
# pin A02: TIM5 CH3 (AF2)
timer A03 AF2
# pin A03: TIM5 CH4 (AF2)
timer D12 AF2
# pin D12: TIM4 CH1 (AF2)
timer D13 AF2
# pin D13: TIM4 CH2 (AF2)
timer D14 AF2
# pin D14: TIM4 CH3 (AF2)
timer D15 AF2
# pin D15: TIM4 CH4 (AF2)
timer E05 AF4
# pin E05: TIM15 CH1 (AF4)
timer E06 AF4
# pin E06: TIM15 CH2 (AF4)
timer A08 AF1
# pin A08: TIM1 CH1 (AF1)

4.3 timer show

# timer show

Currently active Timers:
-----------------------
TIM1:
    CH1 : LED_STRIP
TIM2: FREE
TIM3: FREE
TIM4: FREE
TIM5: FREE
TIM6: FREE
TIM7: FREE
TIM8:
    CH1 : DSHOT_BITBANG 2
    CH2 : DSHOT_BITBANG 1
TIM12: FREE
TIM13: FREE
TIM14: FREE
TIM15: FREE
TIM16: FREE
TIM17: FREE

4.4 timer pin list

# timer A10 list
# AF1: TIM1 CH3

5. 参考资料

【1】BetaFlight开源代码框架简介
【2】BetaFlight统一硬件资源简单配置修改
【3】BetaFlight统一硬件配置文件研读