Hi and
to the forum.
I have no idea as to why the BAC-601 displays are not working on the Smart Pie 5 when they are working fine on the Magic Pie Edge.
The controller on my original Smart Pie 4
(before Bluetooth was available) was clearly marked MP5 on the controller's label, so I initially thought that yours might have been a Smart Pie 4 instead of a Smart Pie 5. However, if it was a Smart Pie 4 controller, then I wouldn't expect the Bluetooth dongle to work with it.
I seem to recall that there were two different versions of the BAC-601 displays, one for the the Magic Pie 4 and the other for the Magic Pie 5 and they were not interchangeable, but as far as I'm aware, the Magic Pie Edge uses the same controller as the Smart Pie 5 and the Magic Pie 5, but with different firmware.
Perhaps the controller in the Smart Pie 5 may need to have its firmware re-flashed, but I suggest that you contact golden Motor in China
(sales@goldenmotor.com) or the supplying dealer and explain the problem you are experiencing and they may be able to supply you with the flash update program and the correct Smart Pie 5 firmware to re-flash the firmware in the controller using the USB programming cable.
If re-flashing the firmware doesn't rectify the fault, then it could be a hardware problem with the controller itself
(or the controller's wiring) in which case the controller might have to be replaced to enable the BAC-601 display to work.
Alan