Hoppy, who was married to Frankel for three years before they split, faces misdemeanor charges of stalking and harassment. He has pleaded not guilty.
He is free on $2,000 cash bail and is due back in court in March.
"There are no words to express how saddened Mr. Hoppy is over his ex-wife's unjustified actions. His only concern is his daughter and intends to vigorously fight these false charges," Hoppy's attorney, Robert Gottlieb, told ABC News.
According to the criminal complaint obtained by ABC News, Hoppy sent a series of text messages and emails to Frankel that “caused her to fear for her safety.” The messages, more than 160 in all, allegedly began in August when Frankel received a text that said, "Despite your games, I'll never let you do to me what your mother did to your father. I'll never go away." The notes included in the paperwork continued through Jan. 17, despite a cease-and-desist letter sent to Hoppy by Frankel’s attorney Nov. 22.
The complaint also indicates on Jan. 17, Hoppy approached Frankel and her boyfriend at an undisclosed location and allegedly said, "OK I see. This is how you want to do this. OK. You can play your game. It doesn't matter. You can get 10 lawyers. There's nothing you can do to stop me. You'll be sorry. You've been warned. I can't help it. She's pure evil. You've been warned. Don't say I didn't warn you."
Frankel, 46, filed for divorce from Hoppy, 45, in 2013. The next year, they reached a settlement over the custody of their now-6-year-old daughter, Bryn, though their divorce wasn't finalized until last July. According to Frankel, theirs was a particularly messy split.
"I'm going through a brutal, brutal time," she told "Nightline" in 2013. "There's no other way to slice it."