Does any African culture have a written language? Without one, there can be no accumulation or transmission of knowledge beyond what can be passed on by word of mouth.
I think the answer is yes if you allowed a borrowed script - Likely Arabic then. Just like Roman script after going through some alteration is ours.
While there may be an exception, Sub-Saharan African cultures did not produce any technological innovations to speak of. Moreover, in places like the Congo, Zimbabwe, and others - the roads, railroads, and buildings that the European colonists built have deteriorated or are simply gone.
There was a thread not too long ago about two Belgian whites who drove a Toyota Land Cruiser across the Congo. I still cannot believe they were able to do it without getting raped and murdered. Anyway, they said that all of the locals said that things went downhill fast when the Belgians left.