In previous article, I reviewed some open source hardwares for children programming, and considered the Micro:bit is the best choice. But recently, after searching many different types of micro-controllers, I noticed an advanced version of Arduino Uno R3 (less than $3) is desperately cheaper than Micro:bit (about $16) in (a famous e-marketing website in China). Despite the low price, Arduino also have a simple and intuitive IDE (Integrated Development Environment):

The programming language for Arduino is Processing, which looks just like C-language. A python developer could also learn Processing very quickly, for it is also a typeless language.
I also find an example code of blinking a LED bubble by Arduino:

// Blinking LED
const int LED = 13; // LED connected to
                    // digital pin 13
void setup() {
  pinMode(LED, OUTPUT); // sets the digital
                        // pin as output

void loop() {
  digitalWrite(LED, HIGH); // turns the LED on
  delay(1000);             // waits for a second
  digitalWrite(LED, LOW);  // turns the LED off
  delay(1000);             // waits for a second

Easy enough, right? But it still have more convenient graphic programming tools, such as ArduBlock and Mixly

The demo of ‘ArduBlock’

The demo of ‘Mixly’

With Easy-learning language, and graphic programming interface, I think Arduino is also a good choice for children programming.