已经做过的排查：
代码已经能控制具体哪个LED亮，可以通过按键切换，可以调节单个LED的亮度，是否可以认为最底层的读写没有问题？
FC1中的CCB/CCG/CCR和BC看起来也是按控制运行的
单个LED（额定电流20mA），串了10Ω电阻，电阻上测不到电压，按LED亮度推断，大约1mA或者更低
电流参考电阻 Riref试过9.1kΩ到6.8kΩ
请问还有什么可以做的？
The troubleshooting that has been done:
The code can already control which specific LED is on, and it can be switched by pressing a button. It can also adjust the brightness of individual LEDs. Is it safe to assume that there are no problems with the lowest-level reading and writing?
It seems that CCB/CCG/CCR and BC in FC1 also operate according to control.
A single LED (rated current 20mA) is connected in series with a 10Ω resistor, and no voltage is measured on the resistor. Based on the LED brightness, it is estimated to be approximately 1mA or lower
tried Riref from 9.1kΩ to 6.8kΩ
what else can I try？
thanks
