115200 is a much more sane "default" than 38400. Instead of a mix of 38400 and 115200, just use 115200 in all places. There's no reason for modern 32bit cpus to be using such old slow baudrates. Tested on f1, f4, l1. Replaced some old f1 code that predated some library support code for this.
README
This directory contains examples for the original stm32f4 discovery. The PCB should be labelled as MB997{A,B,C}, and contains a user USB port, and an audio dac on board, along with a MEMs microphone and an accelerometer.
http://www.st.com/web/catalog/tools/FM116/SC959/SS1532/PF252419
The later stm32f4 discovery boards, for the f401, MB1115B and for the f429i, MB1075B will not work as is with these demos, but they should only need minor tweaking for pin configurations.