In my first post on the Radica/Mattel UCreate, I mentioned adding In/Out connectors to enable the UCreate to be operated by external controls – e.g. joysticks – or the UCreate Button to be used to control other devices.
This post describes two of my devices which I modified for this purpose: the StyloSim and the Black Widow.
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The StyloSim is a two-joystick controller, used for simple flight simulation games. It has two medium-sized joysticks, which are very nice to operate, but no buttons. Examining the controls using the [hid] object in PureData suggested that the chip it uses would support the use of buttons, but this function is not implemented.
The essential task, then, with the StyloSim was to add two DB9 connectors, matching the connectors on the UCreate, so the UCreate’s effects could be controlled by the StyloSim, and whatever the StyloSim was used to control (at the moment, just one PureData program I’d written to add volume, filter and panning effects to an audio input) could also be controlled by the UCreate Button.
I checked to see that the ‘high’ and ‘low’ ends of the potentiometers in the StyloSim were both the same: they would have to be connected together to control the UCreate, but would also have to be left in a state where they correctly controlled the StyloSim chip. They were connected, so I snipped the 6 wires between the circuit board and the potentiometers of the right-hand joystick (which I called ‘VR1′ and’VR2’).
The wires from the potentiometers were connected to the ‘Out’ socket, and the wires from the circuit board were connected to the identical pins of the ‘In socket’. In this way, whatever else I connected, a DB9 lead connecting these two sockets would allow the StyloSim to function as normal.
In fact, I had another addition to make: the potentiometers would have no effect unless the UCreate ‘Hold’ switch was on. As with the UCreate itself, I added a 3 way toggle switch, centre off, momentary in one direction, latching in the other, and connected this to the appropriate pins on the DB9 ‘Out’ socket.
These connections were enough to ensure that, with the use of DB9 leads, the StyloSim could control the UCreate effects, and that the UCreate Button – which had only one joystick – could control at least some of the things the StyloSim could control.
However, the UCreate also now had a ‘Volume Pedal’ output, which just required a potentiometer connected via a 3.5mm stereo socket. As I had two more potentiometers available in the StyloSim, I connected one of these to a switched socket. I used ‘VR4’, the up/down potentiometer of the left-hand joystick, as this was set not to return to centre when released, so would be very suitable for setting a volume level and then leaving it. When nothing was plugged in, the joystick would remain connected to the circuit board inside the StyloSim; when a lead was plugged in, it would control the UCreate volume.
(In practice, unlike the volume pedal, the joystick – because of its limited travel, presumably – didn’t take the volume right down to zero, so was less effective than the pedal, but useful as long as complete silence wasn’t required).
I also made two more modifications, which weren’t strictly necessary, but which were not too difficult and, I felt, enhanced the design.
First of all, I chopped off the USB lead and added a socket instead. This is only because I find it annoying to have fixed leads hanging off devices – it makes them awkward to carry about and store away. Sometimes USB leads are small and fiddly, but at least they’re colour-coded.
(There is some variation in exactly which colours are used, however. There’s supposed to be a convention, but as you can imagine, manufacturers find plenty of opportunity to use colour combinations of their own. Those who are colour-blind – like me – have to be especially careful, but more often than not you can work out which lead is which. Looking into a socket from the outside, 1, on the left-hand side, is +5v, and should have a red or orange wire connected to it; 2 is ‘Data -‘, and has a white or sometimes a yellow/gold wire; 3 is ‘Data +’ and has a green or sometimes grey wire; and 4 is Ground, with a Black or sometimes Blue or Brown wire. I have come across other combinations, unfortunately, of which those using white or yellow for ground are the most annoying. Often there are 5 wires, with an extra connection – frequently black – for the shield around the cables.
Looking into a plug, 4 is on the left-hand side and 1 is on the right.
I’ve mentioned before that I shouldn’t be using Type A sockets as the output of a device that’s being connected into a Type A socket – on, for example, a computer. I should be using a Type B or mini USB socket; but this rule is to avoid connecting two devices together that both supply power, which might cause excess currents and start fires, and this isn’t going to happen with the devices I’m using – the StyloSim, for example, receives 5V from the computer, but doesn’t provide power of its own).
Finally, partly as an indicator that the connection with the UCreate had been properly made, partly because flashing lights are always good, I also added blue and red LEDs to the front of the StyloSim, and connected these to the relevant pins on the ‘Out’ socket. These flash in time with the rhythm of the sounds from the UCreate, when the ‘Hold’ switch is on, so you can tell if the UCreate is ready to receive instructions.
These pictures show the new additions to the circuitry:
and this one shows the StyloSim in operation, controlling the UCreate, with the DB9 and 3.5mm connectors in place, the volume set fairly low, the ‘Hold’ switch on, and the LEDs flashing:
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Essentially, I did exactly the same to the Black Widow. The big joystick on the right-hand side was connected to the DB9 ‘Out’ socket, and the ‘throttle’ on the left-hand side to the 3.5mm volume socket.
In this case, however, there were buttons available, so I was able to use the ‘F4’ button on the top of the joystick as a momentary ‘Hold’; for a latching Hold, I added an SPST switch at the bottom of the front panel, plus the two LEDs, which are illuminated when either Hold switch is activated.
And this is the rear of the instrument – not that neat, but it all works:
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As for the UCreate itself, I made three further changes – but these were more additions, rather than modifications:
1. External power supply. I was pretty certain the UCreate would work with a 5v supply, and was about to use an old mobile phone charger for this purpose; but while I was looking through things I had lying about, I found a better quality one which I’d been given and which was rated at 5.5v, 350mA. I replaced the connector with a 3.5mm mono plug to match the socket I’d installed in the UCreate, and it seemed to work perfectly, cutting out the battery supply when plugged in, and powering the device.
2. Switch box. It occurred to me that there might be occasions when, if I was using the Black Widow and the UCreate at the same time, it might be handy to be able to swap the joysticks quickly from controlling one thing to another, and a way of switching the DB9 leads from one device to the other would be useful.
I was looking into buying a DB9 switch box, which would have been about £5 – £6, but in the end I decided to be stingy and bought three DB9/DB25 adapters for about £4, as I found an unused two-way DB25 switch box amongst my stuff. I had bought this for an as-yet-unrealised MIDI project: as this will probably remain unrealised for some while, I thought I might as well use it in the meantime.
I did find a diagram on the internet to show how the DB9 pins were, according to the RS232 standard, allocated to pins on the DB25 connector, but it doesn’t really matter, as all 3 connections (in/out, A and B) will be the same.
The Black Widow ‘Out’ is connected to the ‘In/Out’ socket on the switch box; ‘Out A’ is connected back to the Black Widow ‘In’ socket; ‘Out B’ is connected to the ‘In’ socket of the UCreate.
3. Feedback circuit. As the UCreate has input and output sockets next to one another on the back, I thought a circuit that connected part of the output signal back into the input, in conjunction with some of the effects – for example, the filter or flanger – could potentially produce some interesting sounds. Having just finished the modifications described in my first post and put everything back together, I decided to do this externally, so added two 3.5mm splitters to the line in and out, and connected them with a lead containing a volume control:
This allows some feedback sounds to be added to the linked samples or to sounds at the line or mic in sockets, and the amount can be limited by the volume control.
In Part 3 of the series, I look at the UCreate software.
Music Electronics 
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