Using old CNC Shield with GRBL v0.9h (or above)

GRBL v0.9h 開始, 可以用 PWM 支援變速主軸, 但同時會將 D11 同 D12 針腳對調.

• Variable spindle is now enabled by default. Z-limit(D12) and spindle enable(D11) have switched to access the hardware PWM on D11. Homing will not work if you do not re-wire your Z-limit switch to D12.

咁就 XYZ 了, 用緊舊既 CNC Shield 點算?
Homing 都事少, 轉左 D11 同 D12 就 大鑊, 針腳變左, 連訊號都唔同左.
平時主軸都全開, 仲有時用激光頭, 唔需要變速, 用 relay 控開關就夠了.
最慘係佢轉左 PWM output, 同 Z-limit 調轉插都唔 work (PWM  控 relay 唔得)
買左塊舊既 CNC Shield 板咪廢左?

好在 GRBL 都預左我呢條 cheap 精, 死都要用舊野 (無錢換新野), 佢都留番一手比我玩.

1. download GRBL 既 source. https://github.com/grbl/grbl
2. 爆開個 zip 將 grbl 既 folder 抄去 arduino 既 libraries folder 下面
3. 打開佢個 config.h, comment 左呢句野:
      #define VARIABLE_SPINDLE // Default enabled. Comment to disable.
4. 開 Arduino, 再 load Example:  grbl->grblUpload
5. 好似平時咁 set 好 port 同 板, upload 上去就得

改完之後, 就可以用番舊既 CNC Shield 玩了.

GRBL 的接腳資料: GRBL's Pin