This article applies to: mBot
If we control the mBot through IR remote controller with the factory default program, the 1-9 keys on the IR remote controller are set to adjust the speed of mBot. 1 for slowest and 9 for fastest.
Here is an video to show controlling mBot with IR remote controller: http://learn.makeblock.com/mbot-get-started/
We can also write our own program for mBot with mBlock software, which can modify the speed on following program block:
Refer to the below link for more information about how to program for mBot on mBlock software: http://learn.makeblock.com/en/mbot-programming/