A Queensland man convicted of possessing and producing cannabis has been jailed at his own request.

The man faced court in Bundaberg in the state's south-east.

Steven John Campbell had pleaded not guilty to the two charges and urged the jury to acquit him on the basis of research he believed proved the drug was not as dangerous as smoking and drinking coffee.

He admitted to the court he produced the cannabis and he knew it was illegal.

Campbell was found guilty, with the jury returning its verdict in less than 10 minutes.

The sentencing judge took into account that Campbell had already served nearly 18 months in jail and decided to release him.

However, Campbell asked if he could spend more time in jail to finish a computer training course and start up a chess club.

He was sentenced to three weeks.