Guest Pyro Posted November 13, 2004 Report Share Posted November 13, 2004 Hi Folks,Is there any reason why one would stop at 128 with MIDIIO128 and no tcontinue to use the PORTs B-E for further lines in output mode?Just pondering up to 900 lines for other apps....Cheers,Pyro Quote Link to comment Share on other sites More sharing options...
doc Posted November 14, 2004 Report Share Posted November 14, 2004 Hi,I think it's "by design".MIOS supports only 128.But you can use 900 if you take 8 Cores !greetsDoc Quote Link to comment Share on other sites More sharing options...
smashtv Posted November 14, 2004 Report Share Posted November 14, 2004 Please tell me you are not planning to trigger pyrotechnic devices via MIDI......Sorry for assuming the worst but I have to ask. ;)Best!Smash Quote Link to comment Share on other sites More sharing options...
Guest Pyro Posted November 16, 2004 Report Share Posted November 16, 2004 Uh. Yes. Why?P.S - I should say that Im a part-time (and unpaid!) professional firework operator - so this isnt a home botch attempt....I have access to electronic igniters and other cat 4 goodies.....Why do you ask!? Quote Link to comment Share on other sites More sharing options...
Guest Pyro Posted November 16, 2004 Report Share Posted November 16, 2004 Hi,I think it's "by design".MIOS supports only 128.But you can use 900 if you take 8 Cores !yeah. But by using multiple MIDI channels, I can use a single module to provide say 256 or 512 lines then I have halfed/quartered my costs and also a lot less hardware to go wrong...before anyone asks this is not for profit - we are just getting asked to perform a lot of displays to music and as a musician who owns a copy of SONAR4 producer I already have the appropriate sequencing in place.I think Ive worked out the 74HC595 -> firing electronics - including safeguard ground switches to ensure no premature firing - and these world be protect by 2 key switches and guarded flick switches - similar avionics switches. The basic idea is to control the entire firing sequence from my laptop - Im looking for this to provide the firing 'trigger' - firing lines themselves would be 12-24V at up to 1amp.... Quote Link to comment Share on other sites More sharing options...
Screaming_Rabbit Posted November 16, 2004 Report Share Posted November 16, 2004 Why do you ask!? ... I think he asks, because MIDI isn't very stable... so your pyro could blow up when you least want it :-/Greets, Roger Quote Link to comment Share on other sites More sharing options...
Guest Pyro Posted November 16, 2004 Report Share Posted November 16, 2004 In what way 'unstable'?Im a s/w eng by trade and Ive been using MIDI for the last 5 years in music - and had relatively few problems.Futher advice gratefully received.The circuit itself would only be turned on just prior to firing when the firing area was clear. ALL cabling would be shielded and properly grounded to avoid interference., and the protection systems would only be lifted immediately before initiating the firing sequence.PS....if you think MIDI is unstable you should read the page on electronic matches at pyromate.com!!!http://www.pyromate.com/Basics-of-Electrical-Firing.htmTry the 'safety first' section!!! Ive got much more problems than MIDI!!! :oCheers,Pyro Quote Link to comment Share on other sites More sharing options...
Guest Pyro Posted November 16, 2004 Report Share Posted November 16, 2004 If necessary I can always put a new MIDI device driver on the PC and write a new protocol (secure/error resistent) and reprog the PIC....my current job is designing/developing kernel level drivers for anti-virus products so I shouldnt have a problem if the MIDI fails testing....Still curious about likely problems... Quote Link to comment Share on other sites More sharing options...
Duggle Posted November 16, 2004 Report Share Posted November 16, 2004 latency issues with airbourne fireworks must play havoch with tight rhythms, I would suppose. Quote Link to comment Share on other sites More sharing options...
smashtv Posted November 17, 2004 Report Share Posted November 17, 2004 Lots to reply to here so sorry for the long post......Uh. Yes. Why?P.S - I should say that Im a part-time (and unpaid!) professional firework operator - so this isnt a home botch attempt....I have access to electronic igniters and other cat 4 goodies.....Why do you ask!?First off, firing any pyro device or moving scenery over a certain weight via any half duplex protocol is not legal in most parts of the world. Even if there is no law in a particular area pertaining to this specifically, you won't be able to find correct show insurance for this method.The only time good inspectors (city, state, federal, insurance) allow this type of system for control (firing via any multiplexed line or wireless) is when the entire show, every device, can be safely fired all at once, same cue.That said, I know that when I key an old Motorola/Nextel phone up next to any MIDI cable over 5 feet, or any DMX line over 100 feet, there will be random data at the other end. Not much you can do about it. There is no way to truly failsafe anything half-duplex.I don't know what country you are in, but the NFPA rules on outdoor displays will cover the electrical and mechanical specifics, and those rules are used as law by many areas worldwide.I used to do a -lot- of proximity pyro in clubs, sports arenas for hockey/football/concerts, and there is nothing like that instant gratification of watching the whole crowd's jaws drop and having fans tell you they felt the heat from the last few rows..... ;DI did my share of arial display work also, but I learned to stay clear of those shows because most of the time these were so unsafe due to practice by the existing crew or venue that it put my license on the line just by being there....I got tired of paying the insurance, dealing with the fire marshalls, and the constant worry about the stupid @*#& musicians, house/band crew, and security who could not remember something as simple as no smoking on the stage until after the third song since there is 4 pounds of powder up there. ;)Just the thought that an all notes off signal has to be used by anything should rule out MIDI for this......Best!Smash Quote Link to comment Share on other sites More sharing options...
Guest Pyro Posted November 17, 2004 Report Share Posted November 17, 2004 Hi SmashTV,interesting.mobile phone + electronic match. Um...this is a major issue anyway - let alone MIDI. One of the rules of using electronic matches are that mobiles are banned from the firing area!half-duplex protocol - This has little to do with with - having designed a number of comms protocols in my life - indeed just finished anothe rin the last 3 months...bi-directional protocols offer no safeguards.What you may perhaps be talking about is non-error corrected/checked protocols.WRT MIDI wires - one of the main problems of midi wiring is a lack of balanced wiring - which would eliminate most problems...an interesting twist....I might think about that further. I think the problem with many MIDI cables is the lack of adequate shielding - most cables are too cheap to be realistic...I would always use my own cables...Also, the MIDI is only from the sound system to the firing unit (MIDIO128 + some) the firing unit can be any distance from the fireworks and will not suffer interference issues at all....so its only the laptop->firing unit which is sensitive...and I can test that over the next year easily.WRT to displays Im in the UK and insurance is a major issue - but there are no problems provided I can prove in testing (i.e. something like 10 dry runs in the field without connections to pyros) to prove the system is safe before use etc etc etc.Its just ideas at the mo and I need to prove it all through stacks of testing...as I said protocols are easy to solve - I can translate midi to an error-detecting protocol & reprogram the PIC if necessary. What I am more interested in is the hardware - software is easy 15 years in the industry down to kernel level + assembler...as for my hardware skills they arent great - hence Ive asked for my grandads help in the electronics (he was an electrical engineer for a giovernment research labs here in the UK)..Cheers for the thoughts and necessary 'restraint' in my enthusiasm though!Its all useful... Cheers. Quote Link to comment Share on other sites More sharing options...
Guest Pyro Posted November 17, 2004 Report Share Posted November 17, 2004 back to the original question - whats the best way to expand to say 256 or 512 lines? is this possible....??? Quote Link to comment Share on other sites More sharing options...
smashtv Posted November 17, 2004 Report Share Posted November 17, 2004 Also, the MIDI is only from the sound system to the firing unit (MIDIO128 + some) the firing unit can be any distance from the fireworks and will not suffer interference issues at all....so its only the laptop->firing unit which is sensitive...and I can test that over the next year easily.Cool. You are on the right track here for the only way this can be done safely. A dead man trigger, line of sight to ground zero, and keyswitches are all law everywhere. As long as your main firing system follows this and the other laws, and every device that's controlled by that panel could fire safely in one massive mis-cue, you should be able to build a rig like this -and- stay in compliance with the laws where you are. If you don't own your own copy of NFPA 1123 get one, don't trust that the practices you are learning are legal or safe.It's one thing to lose some fingers or your own life cause nobody told you a static strap was a good idea when you weighed your lift charge, but it's totally another when a misplaced sandbag lets a mortar rack tip and fire all of your 5 inch shells into your crowd....Both of these were scenarios that I was hired to analyze and report on after the mistake happened. (note I say mistake not accident)I don't have much of anything to do with pyro these days, got tired of even consulting after all of the analysis and reports on the Great White/Rhode Island club fire.Don't ever dismiss radio interference, even if they are banned from your sites, you can't explain to someone's next of kin that someone snuck a radio in, or that someone on site fire/police/security used a radio anyway. Even a powerful AM radio station several miles away can dump enough interference into the ground to generate several volts per hundred feet of cable laying in the dirt, enough to fire an electric match.Every -safe- pro firing system uses transformers on cable runs to try to eliminate false triggering from too much interference. The full/half duplex communication reference is the best way to think of what's proposed and whats needed. Only a full duplex protocol can truly verify that a fire signal is correctly received by the match end before the match is fired. Dig around on the web for a look at the old pyrodigital rigs and others that use this scheme.It's worth noting that the printed DMX-512 specification specifically says not to fire pyro or move scenery with DMX. And it's a much more robust protocol than MIDI.Sorry for the lecture, but the safety of your crowd and crew is worth my time in spewing this crap and your time in learning everything you possibly can about firing systems before you build one.Don't let me discourage you though, seek the "expert firing group" mailing list, they specifically discus building firing systems.Best!Smash Quote Link to comment Share on other sites More sharing options...
doc Posted November 17, 2004 Report Share Posted November 17, 2004 Hi again, back to the original question - whats the best way to expand to say 256 or 512 lines? is this possible....Yes, it's possible by using multiple CORE.Every Core supports 128 lines. You need 1 Core and 4 DOUTX4 for 128 outputs and 4 DINX4 modules for 128 inputs .You can chain the cores by midi.So for 512 lines you need:4 cores16 DOUTX4 for the outputs16 DINX4 for inputs (if needed).Depending on the load you want to switch by the DOUTs you might also need some line drivers for the output modules.hope this helpsgreetsDOC Quote Link to comment Share on other sites More sharing options...
goyousalukis Posted November 17, 2004 Report Share Posted November 17, 2004 I think the 128 limit is set by the speed at which the shift registers can be set. Thorsten designed it to scan all the inputs in 1ms. I assume that the outputs are set in the same time frame. If you alter it to handle more outputs, you would incur a time penalty and might have latency issues. You could look into the Matrix discussions over in the Midification topic. They have been modifying the MidiIO128 for use in organs with Matrices for the inputs. I assume the code could be changed for the outputs. Also, the MidiBox Sid uses a matrix to drive the LEDS in the Modulation matrix. If you are fluent in asm then dive into the IO128 source and see what you can find out. I still think that using multiple cores would be the most reliable easiest way, and the extra cores wouldn't cost that much more.Good Luck, Justin Quote Link to comment Share on other sites More sharing options...
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