Dickinson told BBC Radio Cambridgeshire: "I haven't been playing regularly at Brighton so it's great to have the chance to play regularly.
"I worked with Jim Gannon for two and a half years at Stockport and we've kept in touch since."
Dickinson won promotion from League Two while playing under Gannon at Stockport.
He then moved on to Derby, but found his chances limited and spent time on loan at Huddersfield, Blackpool and Leeds.
"It didn't really work out at Derby so I spent time out on loan and then joined Brighton in the summer," he said.
"The season started off well, but it's all dried up a little bit so I'm just looking to get my form back and help Posh out at the same time."
Dickinson will compete with Aaron Mclean, Craig Mackail-Smith, Izale Mcleod and Reuben Reid for a place up front.
Source: BBC Sport
Source: BBC Sport