Milford sound card triggering
Steve2381
Posts: 94
Has anyone successfully operated a Milford Instruments sound card (part 1-480· - http://www.milinst.com) using a stamp?
I am having a nightmare with these boards, they are so hard to work with they are next to useless.
I connected the 8 trigger pins on the sound card to a 4051 - 8·way switch IC and connected the 3 logic control lines to the stamp.
However, the sound card does not work at all when connected.
It seems that any kind of circuitry attached to the trigger pins on the sound card·plays havoc with its triggering system.
Also, they seem to lose the sound recordings very easily.
The only way I have found of triggering the board is using 8 relays.·· Seeing as I want to use 4 boards, that's 32 relays ..... not an option.
Anyone used anything else for sound events in their stamp projects?· These Milford units are looking like a waste of time.
Thanks
Steve
I am having a nightmare with these boards, they are so hard to work with they are next to useless.
I connected the 8 trigger pins on the sound card to a 4051 - 8·way switch IC and connected the 3 logic control lines to the stamp.
However, the sound card does not work at all when connected.
It seems that any kind of circuitry attached to the trigger pins on the sound card·plays havoc with its triggering system.
Also, they seem to lose the sound recordings very easily.
The only way I have found of triggering the board is using 8 relays.·· Seeing as I want to use 4 boards, that's 32 relays ..... not an option.
Anyone used anything else for sound events in their stamp projects?· These Milford units are looking like a waste of time.
Thanks
Steve
Comments
Have you tried using a transistor to trigger one of the pins?· That's my suggestion --·get an NPN, emitter to ground, collector to the "trigger" pin; connect one end·of a resistor (1K to 10K probably OK) to the base and then touch the other end of the resistor (using a jumper wire or similar) to +5 to play a message.· If that works out (I figure it will) then·do likewise·with the rest (one at a time.)
Post Edit -- I've attached a schematic, it uses a separate resistor to keep the base from "floating high."
Post Edited (PJ Allen) : 12/29/2006 6:32:01 PM GMT
I originally planned to just stick an BC337 transistor across the trigger terminal (yes - one side is ground) and then trigger the base when the sound was required.
However, It doesn't matter how I connect it - pulled high etc, it just constantly triggers the sound card.
I have also found that various trigger methods will lead the sound card to replay a different sound 'slot' to the one you actually triggered and required.
If these triggers are pulled high, then I cannot see why the transistor triggers it.
I am wondering if the triggering system of each individual sound 'slot' is resistance based. That might explain why some of my triggering methods lead to the wrong sound slot being replayed.
Maybe one of the good people at Milford can offer some constructive advise.
I emailed Milford yesterday but no reply yet.
The other problem I have is when you record a sound to the sound card, you get a click from the record push button as the selected slot starts to record.
Nothing seems to prevent this annoying click.
I am in the middle of my·Robotic project.· Of course any robot with sound· will·be much ·better.But sometime to make the sound out of it will cost you time and money.
What I did for the sound is attaching a Personal CD player. Burn whatever sound you like on a CD than use relay to triggering the CD button. Just give Hi and low comand to the relay. Of course it will be a little bit delay time about 2-3 second but the sound quality is awsome and cost me lest than US$20.But u need a little bit more space for your CD drive. In my case I take out all the casing and only use the internal parts.
Just give you some thought.
I already have a cheap cd player attached to my system!
The project I am building is a basically a very complex alarm clock. The alarm sounds and music that the system plays when it reaches alarm time are produced from the cd player I have attached. As you mention, this is just controlled using reed relays controlling the play, forward and stop controls.
My particular cd player needed brief pulses to the cd controls to operate them. If you held the play button down too long, it would pause the cd or if you held the forward track button too long, it would fast skip the cd.
So I put simple one-shot circuitry in between the stamp outputs and the reed relays.
This enabled me to take a stamp output high to operate a cd control, and not have to worry about timing to get the cd control I wanted.
As you also mention, the cd player however is slow to react. Fine for events you can predict (such as an impending alarm time - therefore you can pre-trigger the cd player). but useless for events that happen immediatley.
The sound boards I am using were for sound events that happened immediately and cannot be predicted.
Great minds think alike (allegedly)
Milford technical never came back to me so I don't want to waste any more time on these cards. All 3 times I have used them I have run into trouble.
Milford do an RS232 controlled sound card which may prove better but I don't really want to try it if it turns out to be just as user unfriendly!
The triggering lines indeed appear to be operated by a low signal, therefore theory says they are held high.
However, attaching a length of cable to the trigger pin seems to attact enough rf interference to trigger the board... I can't think what else it could be.
Time to think again
Don't chuck it in just yet, try a 0.1uF cap in parallel (each pin to ground, one end to the pin and the other to ground.)