-- GPIO 腳位 0~3 的寫入／讀回／釋放；hal_mock 只模擬這四支腳位。
for pin = 0, 3 do
  gpio.write(pin, true)
  check(gpio.read(pin) == 1, "pin " .. pin .. " reads back high")
  gpio.write(pin, false)
  check(gpio.read(pin) == 0, "pin " .. pin .. " reads back low")
  gpio.release(pin)
end
log("info", "gpio_toggle done")