Lil Scrappy Is OUT Of Jail Saying "My Arrest Was a Big Mistake" -- Details Inside

Lil Scrappy is Out Of Jail following his arrest in ATL Monday ... and it's all because he failed to check in with his probation officer ... TMZ has learned. We broke the story, Scrappy was locked up in Georgia yesterday for violating his probation stemming from a 2008 marijuana possession case.

But nearly 2 weeks before he was arrested, Scrappy filed documents with the DeKalb County Superior Court, begging the judge to recall the warrant for his arrest.

In the docs, Scrappy admits he failed to check in with his probation officer on August 9, 2012 ... but says it was an honest mistake because he had been on non-reporting status for 1.5 years and didn't know a check-in date had been scheduled.

Scrappy insists he has otherwise been a model probationer and wants his arrest warrant recalled ASAP.

The judge hadn't ruled on Scrappy's request by the time the rapper had a run-in with police yesterday, which is why he was arrested and taken to jail.

Scrappy is expected to go in front of a judge sometime in the near future ...

----------------------------------------------------------------------------------------

NEW UPDATE:  11:30AM

Lil Scrappy is FREEEEEEEEE!!!!!

TMZ has learned ... the rapper has finally been released from an Atlanta jail after being arrested on Monday for violating his probation.

Scrappy's attorney, Mawuli  Mel Davis tells us the judge has put Scrappy back on probation -- the kind where he is required to frequently check in with his probation officer.  He had previously been on a "non-reporting" probation.

As we first reported, Scrappy was arrested yesterday for failing to check in with his probation officer last month. Scrappy also allegedly failed to tell his P.O. that he changed addresses.

Scrappy -- who's on probation stemming from a 2008 weed possession case -- has insisted it was an honest mistake -- and he's been an otherwise model probationer.