Data security is very important in data transmission. There are many methods to make the data to be secure. One of the methods is by using cryptography algorithm to encrypt the data. Using the cryptography algorithm, no one can take the true information except the one with right key and decryption method. In data security processing, microcontroller can be used as a processor. In this paper, a simple cryptography algorithm for microcontroller was proposed for data (text) encryption and decryption. This algorithm can encrypt text (8 characters) with 8 key characters.