From: Jim Meissner (jpmeissner_at_mindspring.com)
Date: 2002-02-05 21:54:41
Dear Group: especially Andreas, Joerg, Jim Peters, Doug Sutherland
Digging through my files while looking for the Mind Mirror stuff, I found a12 bit analog to digital converter I had built. The application note from1990 is for an LT1290 from Linear Technology. What I liked about it is that I could talk to it in Quick Basic. I know that you software snobs will turn up your noses, but I have a lot of wonderful programs running in Quick Basic. It could also be addressed in C, but I have not found C to run much faster than compiled Basic. I don't want to be a programmer, I just want my answer on the CRT display or printer, don't care how it gets there. Sorry about the little rant about all the fancy languages like Java, Linux etc.
Anyway my question is: Which would be easier or faster, 1) transmit the 12bit data from a micro to the PC using RS232 ( as in the Hal-4, BrainMaster, etc ), or 2) have the PC address the 12 bit converter directly. It would require one more line than the RS232 solution, so the opto isolator wouldincrease in cost by $5 (?). The converter can be clocked to give results in 6 usec. Even using a 486-33 the throughput is 3.3 Ksps ( max is 50 Khz ). It would eliminate the requirement of transmitting the sync byte because you can look at whatever channel you want using the PC software. This also eliminates the remote micro and the micro code software. The 8 channel LT1290 uses 5 mA. and the 2 channel LT1298 uses 340 uA.
What are the pro and cons?
How about the interrupt driven comm port software vs. directly addressing the chip.
Juergen P. (Jim) Meissner
Check out my Website at www.MeissnerResearch.com
Read about the benefits of the Brain State Synchronizer sounds for improving your life and health.
----- Original Message -----
From: sleeper75se
To: buildcheapeeg_at_yahoogroups.com
Sent: Monday, February 04, 2002 6:18 PM
Subject: [buildcheapeeg] Re: Brainmaster input stage
Hi Joerg and Jim,
> > So I continue to claim, that the reference integrator
> > hp-filter has very little advantages compared with a
> > simple R-C high pass.
> Joerg, I fully agree with you. I made sure that Andreas
> provided a way on his PC board to defeat this option. I would
> not want to use it. This is basically an auto zero integrator,
> not an AC coupled stage.
What can I say, you've proven me wrong (I like hard facts and graphs
that explains why.) For the next version the integrator will be gone.
Regards,
Andreas
Yahoo! Groups Sponsor
ADVERTISEMENT
To unsubscribe from this group, send an email to:
buildcheapeeg-unsubscribe_at_egroups.com
Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
This archive was generated by hypermail 2.1.4 : 2002-07-27 12:28:38 BST