freaky1310 wrote: ↑
Fri Jun 15, 2018 5:11 pm
Hi, thank you for the answer. About the wiring: since I'm a newbie to the breadboard wiring (and also a newbie to RasPi in general), can I ask you to explain in a very basic way what "ground rail of the breadboard" means?
About the photos: I just thought the were useless since they would be identical to the scheme. Anyway, later I'll take and post them.
Finally, about the motors: they're two DC motors, 4.5V. Don't really know what the precise model is, because there's nothing written on them. If it can help, they're just like the models in the picture, but with (respectively) a blue (front motor, left/right) and a white (rear motor, backward/forward) stripe, instead of the yellow one.
The "ground rail", and the "power rail" are the line of holes / contacts that run along the edge of the breadboard. The holes next to the blue line in the diagram would normally be the "ground rail",/ 0 volts / GND or negative terminal of the battery. The row of holes next to the red line would normally be the 5V, / VCC / "power rail" / positive terminal of the battery. All the points in each row are connected together and are designed to make it easy to route the power supply around your circuit.
You can of course connect anything you like to those rails. Since there are two such rows together on one edge and two on the other edge you could connect 5V regulated supply to the pair on one side and raw battery voltage to the pair on the other side. Just be very careful not to get them mixed up or you are likely to damage something with wrong voltage or reversed polarity.
So, in the illustrartion with "wire in the wrong hole" there is a connection from battery negative to the end of the blue rail along the top edge but further along, in the yellow circle, there is a wire shown that probably should connect to ground but connects to the rail marked with a red line. There are no other connections to the red rail so that wire is not connected.
It is a good idea to show what you have actually built rather than just the diagram you think you built to because mistakes can occur in reading the diagram or placing the wires and components that will not show in the diagram.