Re: TI-H: Motion control and a UNIVERSAL Interface
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Re: TI-H: Motion control and a UNIVERSAL Interface
Bryan Rittmeyer wrote:
>
> Osma Suominen wrote:
>
> > I was hoping I could finish my IR link first so you wouldn't need/want
> > to build one into your EuP. But the problem with the EuP IR link is that
> > it won't work without special drivers. Mine will, and it will hopefully
> > support I2C too (untested, but it should work).
>
> Well, I don't think you should make the IR link support any specific
> protocolsince its much harder than just doing the basic hardware and letting it
> transmit a high frequency sub-modular pulse when it wants to send a high
> and another low frequency sub-modular pulse when you want to signal
> a low (both are "modulated on top of" the 38k "carrier".) Of course, this
> will not be possible if you must make the IR link connect directly to the TI
> without an MCU in between.
I didn't mean that I was going to support a specific set of protocols.
I'm trying to make the IR link as backwards-compatible with the TI-TI
link cable as possible, if you understand what I mean. This means it
will work with the TI link protocol, the I2C protocol and any other
protocols. The problem here is the timing - it will never be as fast as
a cable, but as most protocols the TI uses aren't time-critical, this
shouldn't be a very big problem.
I'm not going to use a microcontroller, believe me or not. Instead, I'm
going to use two carrier frequencies. At present they are both around 40
kHz, but I might increase them to speed up the unit. The duty cycle is
low, maybe 20%, so the carrier signals don't interfere.
> And no, the EuP will have a full graphlink emulation mode... It will become
> totally transparent and function exactly like the normal TI graph link -
> 9600 8N1... At 5 volts on the "bus" and at normal RS-232 voltage levels
> for the PC connector (optional.)
Hmm. That won't be compatible with any other protocol than TI's own. But
of course, that's maybe not a very big disadvantage.
> This will be quite simple - When you turn the EuP
> on it will default to memory mode - But if you run a very small program you
> can send the EuP an op code telling to enter "transparent" Graph Link mode
> where it will stay until manually reset (off-on salute.) So no, no driver will
> be needed other than the tiny (like, 50 bytes or less) program to set
> EuP mode.
Do you need to store this on your calc, or can you connect the EuP to a
calc with no programs and transmit some drivers from the EuP to the
calc, so the calc thinks the EuP is another calc or a PC?
> out there. Actually, as an added advantage, the PIC16F84 will handle all of the
> tough
> protocol conversion - The EuP IR link will not have to be "dual-channel" like a
> non-serial
> link would have to be. In short, it makes things a LOT easier. Still, I'd love to
> see you
> finish your project and wish you good luck.
Hey, I don't want to start an IR link war here :)
But I'd like to see just one standard, and it looks like yours will
never become very popular, but we'll see...
-ozone
--
*** Osma Suominen *** ozone@clinet.fi *** http://www.clinet.fi/~ozone
***
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