timsabre

Yeah I've played with wled for pixelly stuff. This is just to control 48 dimmers, like an old fashioned lighting desk! I normally use a 3.3V RS485 chip to link DMX to ESP32 and it seems to work fine both ways.

I have an application where it would be really handy to program up an ESP32 as a basic DMX controller - wired DMX output, but control from a browser on a phone via wifi - just a few faders to program a state and a few scene buttons to recall states. Power up automatically into the last used state. Given the variety of ESP32 software out there I am surprised that nobody's already done this but I can't find anything, everyone is busy mucking about with pixels, do any of the tech dabblers on here know of something? I have various DMX libraries and I could write my own but why reinvent the wheel if someone's already done it...

It is a tribute to Avo's design that there are still a lot of classic Pearls out there running shows! But spares availability will gradually kill them off.

Well any digital comms protocol is the same, they either work perfectly or very very badly. Because DMX has no error correction it is probably easier to spot approaching trouble - protocols with error correction tend to mask any minor problems so you go from 100% to nothing, with DMX you do start getting dodginess that indicates something is going wrong.

I share your pain about Google but I have ended up using Google calendar because it just works and can be linked to pretty much everything.

Well you might be right, it's a square wave so who knows. The fact is I've spent a lot of time working with DMX as a fixture developer and in some weird and wonderful configurations and only ever seen problems when combining a passive split with long cable lengths and another fault like one-legged DMX. I agree with whoever said above that DMX will run over spaghetti.

It's quite rare to have active split circuitry in a fixture, mainly because if the fixture fails or loses power you don't want it to break the DMX line, so then you have to put failover relays in and stuff which just adds complication and expense. Most fixtures have surge protection on the DMX input which may be what you can see. The real answer to your "internal passive split" question is given above, it is all about how much cable is connected to each "leg" of the split, and the very short length inside the fixture is insignificant, so it doesn't cause the problems that you can get with a passive split with long wires on it.

The trouble with the "buffered" type device is that it blocks RDM, though not many people seem to use that. Terminators are very good at showing up other problems e.g. if you are missing the + or - side of the signal it will probably work without a terminator but not with one. It seems to me from a not very statistically significant survey of temporary event rigs and installs I have seen, that hardly anyone routinely uses terminators.

A quarter wavelength at DMX speed of 250khz is about 300m. So as Kevin says the short length of "T" cable inside a fixture is not significant, and indeed very few DMX installations will get anywhere near 300m of cable. As the others have said passive splitting DMX will nearly always work but can come back to bite you later at an inconvenient moment, often in combination with a different fault. If you are planning a rig - don't do it. In an emergency - maybe but be prepared for strange things to happen. I've been on a few jobs with Robe fixtures having both 3 pin and 5 pin DMX connectors, where these connectors had been used as if they were an active splitter (they aren't, they're just wired in parallel). All worked fine until a faulty DMX cable with broken "+" conductor came into play, then extremely weird random movements started happening.

Hi and welcome to Blue Room. Assuming you are near a city in Australia, there will be lighting hire companies who would hire you a machine by the day to experiment with. That is the only way to find out what would suit your needs. I would avoid the cheapest machines as they periodically turn off to heat up so you press the smoke button and nothing happens. The more expensive ones will make smoke while they are heating. You say a "plume of smoke" which suggests vertical smoke to me, the machines you list will all squirt out smoke horizontally and you can't tip them above about 45 degrees. If you need vertical smoke look at the Chauvet Geyser which specifically does that - they are pretty powerful and would be fine for your intended use. They have built in LED lights to colour the smoke too if you need that.

See post #2

Thanks for replies. We will consider the best option, I hadn't thought of the braided sleeving or spiral wrap. I assume braided sleeving is described by its minimum size, i.e. 10mm sleeving expands to 30mm or whatever? It's interesting to know that someone else has come up with the same loom solution as us. We seem to have ended up with 3 types of loom, acoustic instruments (XLR+Cat5), electric instruments (XLR+Cat5+Mains), keyboards (4x XLR+Cat5+Mains).

The church where I help with sound recently started meeting in a school. We have a full (but variable) band and setup/takedown time is limited so to save lots of mucking about with cables we have made cable looms to go to each instrument in the band containing XLR(s), Cat5 for P16 monitoring, mains power for pedals etc. These all plug into a sidestage rack with an S16 digital stagebox and some mains distro. Initially we have taped the cables together with PVC tape but this is gradually coming off. I don't really like cable ties for this purpose as they tend to be a bit jaggy on the hands. Does anyone know of a magic product for keeping cables together, or maybe we just need a good brand of PVC tape that will stay on? Large heatshrink is one idea but it's quite a bit of work. The cable looms are between 5-15m long.

It's a big lump that people fall over... If the cable is in a public area

Paying a self employed persons invoice does not make you an employer. Unless they only ever work for you.

Probably a silly question but I assume you have checked that your borrowed PTZ camera uses RS232/RS485... Serial control seems to be gradually being overtaken by ethernet/IP. Every manufacturer has their own version, but the ones I have got involved with you just send an http request with some attached parameters to move the camera to an absolute position (there are also relative up/down/left/right commands for manual control). e.g. for the Panasonic cameras you send "http://192.168.x.x/cgi-bin/aw_ptz?cmd=APCxxxxyyyy" where x=8000, y=8000 is "in the middle" For pelco-P or pelco-D if you want absolute positioning you need to program presets and then recall them. It's very easy to do over the RS485 though.

Jem's digital remote protocol is just 5V serial at 1200 baud. I wouldn't expect to hear any noise. On the other hand I think some of them had 0V and power on 2 of the pins and sent a 0-10V analog signal back down the 3rd pin to control the machine - I think that is why there isn't a "ready" light on the remote.

I wrote parts of the firmware for ZR33 and ZR44 but I am mixing them up in my brain - I think ZR33 had dip switches and a separate DMX interface which sent analog to the main board, but ZR44 had a digital interface panel with the DMX integrated into the mainboard. If it has a separate DMX->analog module, those sent out a "standby-active" voltage of 1V when DMX was received, which would cause the machine to heat. 1-10V then would give varying levels of smoke. 0V would shut down the heaters. This was combined with the voltage from the remote, highest voltage takes precedence. But I might be confusing it with other Jem products. I think the remote might have been on a 3-pin XLR using a digital protocol to connect rather than the voltages used previously.

The control of ZR33 is entirely done by software, it checks for most likely problems with the thermocouple and won't heat up. So it could be an intermittent problem with the thermocouple connection as Rob suggests. Where is the remote for this machine - docked in the back of the unit or on a long wire? The "Standby" button on the remote must be pressed to make it heat up, if there is a problem with the connection to the remote then that could result in it not heating or heating intermittently. If the remote is on a long wire I would try plugging it directly into the back of the machine and see if that fixes it. I am not sure if you can call Jem Service directly any more since they were assimilated by Martin and then Harman but if you can get to talk to them they would know the answer to this, quite a few of the original team still work there.

If you use an atem mini as suggested earlier it doesn't add a noticeable delay, max 1 frame I think. The projectors will probably add 1 or 2 frames delay as well.

Yes architectural floodlights would be my first place to look. Have a look at Concord Lighting, they make some good focused exterior lighting - they tend to use multiple individually lensed LEDs, not like theatre fixtures, but work well.

Sorry but those manuals are not relevant to the 305HP. The manuals linked to on our website are from more recent history when Abstract bought the Mad trademark and released some different units. The 305HP is from the original range of Mad scanners. As Paul says they were 4 DMX channels. Some of them had a novel pushbutton interface with a single 7-segment display in place of the usual dip switches. I can't remember how that works.

C always casts byte to signed int when you do a calculation, you don't need to do it separately. The trouble comes when int is 16bits (mega arduinos) as 32767 isn't all that big and quite easy to overflow. On ARM arduino it's 32 bit so doesn't overflow. I've started defining things as uint_32t or uint_16t rather than relying on the compiler to set the variable size, can save a lot of head scratching.

Highbyte and lowbyte won't work for this as they are making 8 bit numbers and yours are 7 bit So if v is your 16 bit signed value as described above a=(v>>7) & 0x7F; //get the upper 7 bits b=v & 0x7F; //get the lower 7 bits (edit: that is the character "x" not a multiply, i.e. a hex value. Seems the forum software is being clever and changing my x to a multiplication symbol)

Usually it's a section of loop wiring has got damp. It doesn't seem to affect the loop amp at all but it certainly affects audio and video equipment in the room. You're right about problems if you run the cables close to the loop cable, I've had that too on vga.