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 Robotics / 20018
    Re: I2C device for the RCX —Mark Riley
   (...) high (...) frames (...) very (...) anyone (...) I (...) BrickOS (...) In the current release of BrickOS, the motors only get updated by the timer ISR every 2ms, so that probably explains why trying to twiddle the bits any faster than that (...) (22 years ago, 11-Jan-03, to lugnet.robotics)
   
        Re: I2C device for the RCX —Bastiaan van Kesteren
   Hum. i think my first post was not very clear( and whit some stupid mistakes) I think you now how I2C works: there are to lines, SCL and SDA. so whit this device, I got to sensor ports, one for SCL and one for SDA. making high and low signals on the (...) (22 years ago, 12-Jan-03, to lugnet.robotics)
   
        Re: I2C device for the RCX —Gunther Lemm
   (...) I think it will - as long as you put the sensor handler on timer B (the motor handler probably can stay there too). Take a close look at _ds_handler inside the file dsensor.c. That's where all the active/passive switching and sensor readout is (...) (22 years ago, 12-Jan-03, to lugnet.robotics)
   
        Re: I2C device for the RCX —Bastiaan van Kesteren
   Before starting the hacking,I did some tests whit this 'for-lus-delay', and I found the results better than expected. I found that this: for(long i=0;i<100000;i++); takes about 120ms, so one for lus takes 0.0012ms. I made a test program which first (...) (22 years ago, 13-Jan-03, to lugnet.robotics)
   
        Re: I2C device for the RCX —Bastiaan van Kesteren
     (...) Nope, I didn't. Mixed up the packages/sec and bits/sec. It should be 6360Hz. Sounds even more faster (-: (22 years ago, 13-Jan-03, to lugnet.robotics)
    
         Re: I2C device for the RCX —Bastiaan van Kesteren
      ARGH!!!...!!! i'm getting nuts of all these numbers! Now it appears that my stopwatch didn't give the time in steps from 1 ms, but in steps from 10 ms so then the program takes 3750ms, which means 70,6 packages per second. the RCX has send 1 adress (...) (22 years ago, 13-Jan-03, to lugnet.robotics)
    
         Re: I2C device for the RCX —Dick Swan
      "Bastiaan v.kesteren" <b.van.kesteren53@zonnet.nl> wrote in message news:H8o02v.Gpz@lugnet.com... (...) 375ms, which is (...) at the sensor (...) 6360Hz. (...) I don't understand your references to clock pulses. The I2C protocol is edge triggered (...) (22 years ago, 13-Jan-03, to lugnet.robotics)
   
        Re: I2C device for the RCX —Dick Swan
   "Bastiaan v.Kesteren" <b.van.kesteren53@zonnet.nl> wrote in message news:H8nvnF.2rz@lugnet.com... (...) takes (...) package, (...) A 3% error rates (7 out of 250 messages) is far too high. I would have expected error rates under 1 in 10 million (...) (22 years ago, 13-Jan-03, to lugnet.robotics)
   
        Re: I2C device for the RCX —Bastiaan van Kesteren
   Dick Swan wrote: >I don't understand your references to clock pulses. The I2C protocol >is edge triggered with a data bit transferred as the clock signal >transitions from a LOW to HIGH value. Where do clock pulses come into >play? OK, as a (...) (22 years ago, 14-Jan-03, to lugnet.robotics)
   
        Re: I2C device for the RCX —Gunther Lemm
   (...) Lepomux works with a serial protocol (5 bit preamble, 8 bit data, parity) based on a halfbit-clockspeed of 1 kHz. So compared to your I2C-driver it is dead slow (about 33ms/byte = 30 bytes/s). This slow speed has two reasons: - it's possible (...) (22 years ago, 14-Jan-03, to lugnet.robotics)
   
        Re: I2C device for the RCX —Bastiaan van Kesteren
   (...) Well, one reason for this is that I2C doesn't need a precise clocksignal (thanks to Dick Swan for telling me, I totally forgot about it). All the timer stuff shouldn't matter for the I2C device, so there should be even higher speeds possible, (...) (22 years ago, 15-Jan-03, to lugnet.robotics)
   
        Re: I2C device for the RCX —Gunther Lemm
   (...) We'll first check it out before boasting about it ;) The whole thing won't work without some hardware modifications on the lepomux - so I'll tell you about it in two or three weeks. Gunther (22 years ago, 15-Jan-03, to lugnet.robotics)
   
        Re: I2C device for the RCX —Gunther Lemm
   (...) ... took slightly longer than 2 weeks, but now it works as expected. Using BrickOS you'll get up to 100 byte/s without any patch. I've put a protocol description on www.lepomux.org. Gunther (22 years ago, 1-Mar-03, to lugnet.robotics)
   
        Re: I2C device for the RCX —Bastiaan van Kesteren
   ** For some reason my e-mail didn't work anymore, so i couldn't post any messages to Lugnet. that's why i'm responding so late. So , hoping this time it will work, I send my post, again(for about the 10th time...) ** It looks very good! You say(on (...) (22 years ago, 14-Mar-03, to lugnet.robotics)
 

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