The redback input power pin is called RAW and it is connected directly to an onboard 5v voltage regulator and from there to the 5v output pin. When I connect a 7.4v battery to the RAW pin the 5v output pin on the redback is only putting out 3.2v.
I wired together a 5v voltage regulator with capacitors to filter the output so it stays at a steady 5.02v. When I put this into the RAW input pin the 5v output pin on the redback is only doing 3.2v.
In every scenario the 3v output pin is pushing 3v.
My understanding of the architecture of the redback is that the onboard 3v voltage regulator is put in line between the 5v regulator and the 3v output pin. However the power levels I am reading on the 5v output would seem to suggest that there is an issue with the setup on the redback.
When I run the redback from the FTDI USB cable that has the 6 USB header pins the 5v output pin pushes 4.6v which is what the power readings show when I measure the VCC and ground on the USB header while I have it plugged into my laptop. Since the VCC pin is wired to the 5v output I thought I would ask if I am going to burn anything by wiring my regulated 5v supply to the VCC pin. The VCC pin is also connected to the TTL parts on the board, for serial communication. If I only wire 5v to vcc and ground on the same header I would think everything should be fine. I'm basically looking for somebody with more knowledge than myself to affirm this guess if it's possible.
Thanks oric_dan!