Following a link posted on the NGF forum, I purchased a control board and a pack of 10 small servos. Thinking about it, I realised that 10 servos could draw a fair whack of current. I can’t quite, realistically, think of a situation where I would ask them all to be on the move at the same time but since the things can be used in parallel as it were, I decided that a suitable power source was also justifiable. An eBay search brought up a suitable unit rated at 5 volts and capable of 10 amps of current, so, that was acquired also.
The next stage is to put the control board together. Chasing it up a little I found the manufacturers website. It’s made by adafruit. A strange company they are, with a broad and peculiar range of products. However, I have used some of their items before and found them to be reliable. Chasing round the site, I finally found a link which brought me to this: details of the board including construction. Yes, construction, I would need a soldering iron – there are around 60 solder joints to make on this thumb sized board! I am well practised in the soldering art so it didn’t take long to put it together.
OK, moving on... Before you get too much into using servos you will find that most setups and programming is done from a starting position which is in the centre of the travel of the device. It’s annoying as anything getting the device to that position. It’s a REALLY bad idea to try to turn the servo by hand. It’s very easy to strip the gears or even suffer a split gear (argh! Heard that expression before?). So, eventually you will want to get your hands on one of these:
They come in a multitude of flavours, in a range of different prices and under many names. I’ve seen them called ‘Servo Tester’, ‘Servo Exerciser’, ‘Servo Setter’ and even ‘Servo Thing’. Prices range from £1:99 to £9:99. Don’t pay big money for one, though you may wish to pay the premium for a local supplier – the £1:99 one was from Hong Kong and was going to take 3 to 4 weeks to arrive. The device has three functions. In mode 1, rotating the knob will cause the attached servo to move appropriately. Mode 2 sets the servo to its starting, or neutral, position. Mode 3 will cause the servo to cycle between approx. 45degs and 135degs. The neutral position is at 90degs. Under program control the servo will be able to cover approximately 0 to 180degs.