RC Boat for Wetlands switched to Power Transistors

Experiments with SG90 servos and board resulted in failure to drive the motors.

http://www.ee.ic.ac.uk/pcheung/teaching/DE1_EE/stores/sg90_datasheet.pdf

So rummaged around in component boxes until I found some power transistors.

The 2N3054 should do the trick:

https://octopart.com/datasheet/2n3054-comset+semiconductors-29378570

https://www.homemade-circuits.com/dc-motor-speed-controller-circuits/

I ended up with a diode across the motor with both between th NPN collector (case) and +5v from a USB power bank. Then a 2K2R resistor from base pin to micro:bit and emitter connected to GND.

Also have a red LED (longer lead to +5v) and 670R resistor across water pump motor as a visual indication.

With the NPN viewed from behind with the two pins furthest away from you the emitter is on the right (with base on the left)

Next, after testing successfully using a breadboard last night, 

I decided to commit two channels to a veroboard this morning.

Got one wired and works if signal in connected to +5v (i.e. LED and motor turn on) but not when driven by 3.5v signal from micro:bit! Strange as this worked on the breadboard last night!

After some fiddling it finally worked. So loose cable maybe? Now wiring up the second transistor.

Got second channel working (LED on when signal taken to +5v) but first channel now broken!

Fixed. Was loose solder to collector casing.