He's too busy for me?

I know it's a classic brush off but in his defense he does have a busy life and told me he is currently working a lot of overtime (shift work too). When he's busy, I never hear from him. When life settles down, he texts me again. I like him (more than he likes me, obviously) and I know he has a crush on me (he told me). So, how do I get on his radar? How can I get him to text me, even just to say hi or something? Yeah, life is busy, but I would still like to be a part of his! My last text to him was, "okay, text me when you're not so busy...until then take care." Guys, is there anything I can do besides waiting it out? Is there a chance that I'm on his mind even though I'm not hearing from him?

...I am worried he'll forget all about me but I don't want to be texting him all the time when I know he's busy. That's too clingy.