Fix and extend sample in apa102 module docu (#1689)

docs/en/modules/apa102.md

@@ -30,12 +30,18 @@ Send ABGR data in 8 bits to a APA102 chain.
 #### Returns
 `nil`
 
-#### Example
+#### Example 1
 ```lua
 a = 31
 b = 0
 g = 0
 r = 255
-led_abgr = string.char(a, b, g, r, a, b, g, r) 
+leds_abgr = string.char(a, b, g, r, a, b, g, r) 
 apa102.write(2, 3, leds_abgr) -- turn two APA102s to red, connected to data_pin 2 and clock_pin 3
 ```
+
+#### Example 2
+```lua
+-- set the first 30 leds to red
+apa102.write(2, 3, string.char(31, 255, 0, 0):rep(30))
+```