How the STATE DMX testers are made.

I have been asked by a few people how it works, so here it is. It is quite an involved process although the machines do the hard graft. It is of course possible to get someone else to assemble the circuit boards and make the enclosures, but that is neither fun, nor cost effective at this stage.


I designed the PCB using CadSoft EAGLE, I send the files away to be turned into a board.

The enclosure is designed in CAD, and then I use Lazycam & Mach3 to convert the drawings into GCODE ( a set of really simple machine instructions that tell the cutting and engraving tools where to go and what to do).

The software on the unit is written in C++, and that is probably the subject of another post.  I get ideas from time to time about how the interface could be developed or made easier to use from the people around me at work.

The PCBs arrive and are populated with components. I do this by hand, due to the low volume. Some of the components are are very small  (<1mm ) so some concentration and a magnifying glass is needed. I use solder paste and a small tipped soldering iron and work on a number of boards at once, placing each part across the whole batch.

First stage of testing is completed at this to check voltages and battery charging operation are OK.

The encoder side panels go into the CNC machine to be cut. I do these first so that the assembled PCBs can be then attached to them while other things are happening, like adding the red switch caps and the OLED screen.

The XLR backplane is soldered up, this has a little bit of ribbon cable that needs a crimp header crimping onto it that connects it to the main board

The XLR end panels go in for CNC milling. I usually do these in batches as it is quicker to set the machine up once and then just keep feeding it material.

Each panel takes about 5 mins to cut.  The XLRs are then screwed into the panel.

The polycarbonate windows are milled in the same machine. Due to the thickness of the material they are done one at a time, any more the warping caused by the clamps mean that the final size of window is not accurate enough.

The main body of the tester is now milled. All the square holes are cut first and the 1mm recess for the window. Then it is time to change for the engraving tool and the engraving is done.

While the machine is working hard cutting holes the PCBs go over to have their processor fitted and flashed with software. At this stage I modify the line in the code that sets the customers name on the splash screen. Spelling of the name is not my strong point, so this needs to be checked at least twice!

The windows are snapped into the main body and the whole unit is assembled, adding the LiPo battery and encoder knob.


Once the unit is totally assembled I then walk it through some function tests, checking that all the buttons move ok and do what they are supposed to do.  I then check is the unit outputs DMX within spec, and receives DMX ok.  MIDI is checked against an MSC output from Qlab. The last step is to verify that LTC functions correctly by plugging the unit into a timecode generator. 

The last stage is to print the manual, and then check everything into the postbag, making sure not to forget the little purple bag or LTC/MIDI adaptor.




Switch6 is a simple DMX relay card. Unlike the DMX relay cards that you can readily buy its relays are rated to 16A per channel, and the current is kept of the PCB through use of tab top relays. I’m going to build some of these cards into enclosures with socca out, to use as a proper relay backfeed for a AVO dimmer. You could use it for anything else that needs switching. It has a standard piano dipswitch for address setting.

STATE: Back in Black

STATE Dmx Testers are back in stock, in black. If you want one in silver that is also ok, but the black looks cool.
I am calling these units R3. They are the same as the ones that are currently out there except for the black finish. Perhaps more interestingly, they have the ability to record DMX Snapshots. So if you plug it into you console you can save a look (or 200 looks) and then play them back at a later date. This might be useful as a backup for example, or for a situation where you need to flash in the setup of a load of standalone fixtures. You could even use it (or loads of them) as little lighting systems for an event. If you were feeling keen, a number of snap shots could be recorded as a test setup for moving lights. The states are saved in non volatile memory, so will be retained if you turn the unit off, or run it completely out of batteries.

Once you have loaded back a memory the levels recorded can be adjusted live. There is currently no fancy fade times etc between memories, it simply records all DMX channels incoming and saves them in a memory marked 0 to 200. There is a bit of space for more memories but I am saving that for future software revisions.

Buy one here

ETC EOS Moving light focus Photos….

A few years ago I wrote a bit of software to automate taking of focus photos using a strand500 and MIDI. It is time for an update, I have been sitting in the theatre writing this in gaps between being needed smashing keys on the typewriter. This time it works with ETC desks using the remote client connection and dongle, and takes photos using a Cannon camera. The application renames the files downloaded to the computer by Canon’s own software, with the channel and preset that it has driven the light too.

The presets photos that need to be taken are saved in a .CSV file in the application folder, a line for each.

This should speed up the process of documenting my moving light focus in a weeks time. Still to do is an parser to automatically generate the ‘used preset’ list, but that is for another day.

You can see me doing a terrible demonstration here.

CurrentBun RDM

I have just sent for fabrication some prototype PCBs for a new CurrentBun system. The idea is to report via RDM:
• Current RMS across three phases
• Voltage RMS across three phases
• Frequency, P.F.
• Local temperature to the unit

This first spin of the board has an 2500V isolated DMX port for RDM communication, a local display and interface for settings and readings and a real time clock / SD card socket so that readings can be logged locally.

The idea behind this unit is that you could use it to report current draw on a system remotely i.e. at your dimmers/distro from your desk, using the standard DMX infrastructure that you already have in place.

Lots of software to write!

at the place where three footpaths meet, there is MIDI

This month I have working on a number of different devices that send simple MIDI messages from simple inputs. Wireless buttons to midi notes, simple switch to configurable MSC message etc. Why MIDI ?, it seems to still be the easiest way to get new human input into an existing product, or the control product of choice. Sound, video and lighting people can all agree on it. Perfect.


Exhibit has a wide ranging remit, essentially inspired by a need for an easy way to interface lighting, sound video etc in a museum or gallery, or interactive performance. This project was inspired by the 5sq XGO I used for the War Horse Exhibition, and also incorporates the features of the MIDI to DMX bridge. I have designed Exhibit to be as flexible as possible:

• 84 contact closure inputs (expandable) for switches etc.
• MIDI out – programmable Notes, Controllers, SysEx, MSC etc
• DMX 512 in and out – control lights, trigger consoles, media servers.
• Analogue sensor cards can be fitted to allow environmental sensing etc.
• LCD display shows status of inputs and outputs.
• Internal logic – The unit can be programmed to do useful things eg lockout inputs until an event, AND, OR, NOT sort of operations of inputs can simplify programming of installation.

• Inputs are via RJ45 connectors, allowing use of cheap network cable for large installations
• ExhibitTerminal is a RJ45 to terminal block PCB – for easy connection of switches to network cable.
• Internal PSU for easy and secure installation.

Missing your Strand 500?

For those of us who are occasionally ridiculed for referring back to the desk that we once knew and loved, I have bodged this Strand Designers keypad to work with the ETC EOS. Kindly donated by a friend this original designers remote has 71 actual Cherry keys, with the familiar click of a Strand 500 console, not a nasty membrane keypad in sight. The device was originally used with a 510i backup unit or a designers PC so you didn’t have to remember the shortcut keys. These shortcuts are embedded in the hardware, with a single PS/2 connection to the device you wanted to control.

I have removed the original PS/2 cable and implanted a Teensy2.0 USB microcontroller, allowing me to remap the Strand keys to EOS functions, and use a normal USB connection to a EOS PC or console. Wait becomes Follow. Preview becomes Blind. You get the idea. Its just for fun… but you could use it for a bit of offline programming. Or just to remember what nice keys felt and sounded like.

Buttons! – Enclosed!

Steel enclosures for the 4×2 button interface have arrived from HOLT Broadcast. This project might now appear on a production desk near you.

Remote controlled alarm: Metamorphosis

Practical projected – Alarm clock on stage with switch, wirelessly controls bell unit. Both units have a button that can start and stop the alarm ringing. The remote bell unit also has an auxiliary contract closure input to allow cabled control. Actor can stop ringing bell, started by Stage Management, or vice versa.

new radio dimming boards have arrived!

New version of 3 channel radio dimmers have arrived. Similar to the original model, 3 channels of remote controlled PWM dimming suitable for LED tape etc but this time improved with a double sided PCB, an addressing button and greater dimming capacity.

The boards construction will mean that the interface between the terminals and the PCB is much stronger, so failures due to over tightening should be lessened.

The first version of these boards controlled the LED Orbs you can find in another entry.


Latest project is 8 good quality programable buttons. Plug into your computer or console via USB. It can press keyboard keys (to suit any lighting online/offline software package) or MIDI via USB, to interact with Qlab etc. The original idea came from a need to give a Lighting designer a remote to navigate his channel display screens. Just needs a box…..anyone with CNC facilities, please call!


This project has been on the table in various prototypes for about two years now. It started as a need for a way to measure current usage in a venue were we were on the edge of what was available. It has been through a number of different hardware iterations and here is the latest one. It is able to measure current and voltage across three phases, log and display the results through an internal webserver. The eventual aim is to allow Midi Show Control input so that the current consumption per cue can be evaluated.

Current sensing input is via three 300A capacity current clamps. It needs a live feed from each phase, that could be 3 16A supplies. It has a LCD display so that it can work as standalone, or you can plug into a standard network and investigate the results via a web interface – graphs etc.

Still lots of work to do on the, but for the moment this is a working prototype that hopefully I can start some experimental logs with on a show soon.

Prototype shown at the Green Lighting Social 15th Jan:

ArtNet to Video pixels.

This application takes five universes of ArtNet and turns them in to RGB values for squares. You can choose the square size from 1 to 100 pixels, and how many squares are on each row. For turning a console output into something you can use for VersaTUBE.

Mini DMX Tester: STATE

This project has been on the table for a very long time, and probably will continue to be developed as it still has incomplete features.

The idea was to create a better DMX tester. There are five modes,
DMX State – Where each channel level is retained and a state can be created.
Chan Check – Channel @ Level Rem Dim.
Autofade – A sine wave is applied to the chosen channel.
Autofade range – A sine wave is applied to a number of channels in sequence.
DMX in – Displays 8 channels per page.

The unit has a tiny OLED screen, and a LiPo battery charged by a mini usb socket on the side.

As it hold the state, it could be used to replace a lighting desk in one of those “we just need to turn the LEDs on” sort of situations.

Developments to include:

Storing of more than one state.
DMX in socket.
Better housing.

NEW, board, enclosure, and in production for sale! – see here…