 | | Re: Lego Network Protocol questions
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(...) Oops, I must've just caught the tail end of the conversation. I assumed the standard [lame] lego protocol was being discussed, not a custom protocol. Sorry. Dave (25 years ago, 2-May-99, to lugnet.robotics.rcx.legos, lugnet.robotics)
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| | RE: Lego Network Protocol questions
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With all of the talk about networking and IP embedding and such, and since I'm working on a proprietary '485 master/slave protocol for a client, I had to dust off a GREAT university text on networks. It devotes an entire chapter to ALOHA and slotted (...) (25 years ago, 1-May-99, to lugnet.robotics.rcx.legos, lugnet.robotics)
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| | Re: Lego Network Protocol questions
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(...) Dave, did you catch the crosspost from lugnet.robotics.rcx.legos? I think there were details discussed there that may or may not have amounted to a fairly specific proposal for a protocol for LegOS. Anybody care to summarize whatever was (...) (25 years ago, 1-May-99, to lugnet.robotics.rcx.legos, lugnet.robotics)
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| | Re: Lego Network Protocol questions
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(...) Transmit whenever you feel like it and hope you didn't obliterate data coming from the other direction. Rudimentary, but still quite effective given the typical use pattern with is host driven command/response. With RCX to RCX communication (...) (25 years ago, 30-Apr-99, to lugnet.robotics.rcx.legos, lugnet.robotics)
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| | Lego Network Protocol questions
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Hi all. I came to the discussions on the LNP a bit late and was wondering if the following questions had been discussed (I flipped through an old Communications course book and noted some thoughts): - Can we do Carrier Sense *whilst* we are (...) (25 years ago, 30-Apr-99, to lugnet.robotics.rcx.legos, lugnet.robotics)
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| | Re: IS free()'s operation atomic?
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(...) I agree, free() is not ISR safe. One thread can get preempted after the check but before the store, and a second thread can adjust mm_first_free, making the first thread's check invalid. -Kekoa (25 years ago, 29-Apr-99, to lugnet.robotics.rcx.legos)
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| | IS free()'s operation atomic?
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Hi all I think that free() operation in mm.c is not ISR safe in multitasking mode. This operation is not keep coherence about value of mm_first_free,is it? ---...--- in mm.c ---...--- // for task safe operations, free needs to be // atomic and (...) (25 years ago, 29-Apr-99, to lugnet.robotics.rcx.legos)
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| | Rom sensor read routine
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In writing some sensor code yesterday/today (it's 6 am), I passed over the ROM sensor code at 14c0. The documentation has been put in the usual place. The rotation code is pretty simple: the expected state machine, with split points between the four (...) (25 years ago, 25-Apr-99, to lugnet.robotics.rcx.legos)
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| | Re: legOS Network Protocol
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(...) given (...) lego (...) [ stuff about lego/native collisions ] (...) of a (...) on (...) I was wondering, since people are considering using tags in the LNP frame to signify local to local messages, could we not also use this to "label" non (...) (25 years ago, 23-Apr-99, to lugnet.robotics.rcx.legos)
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| | Re: loading s/w
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(...) In my brief experimentation with rom_reset(), it does not actually clear the rom- rather it only starts the program over again (in main()). Is this intentional? I get this behavior when calling it from main- when calling it from within another (...) (25 years ago, 21-Apr-99, to lugnet.robotics.rcx.legos)
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| | Re: Rotation sensor bug found
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(...) This seems the best approach to me too. My problem is I don't know if I am able to do such a thing :-) (...) I know your site and know you've done a LOT of hard work to understand and explain both RCX hardware and original firmware code. Mario (25 years ago, 21-Apr-99, to lugnet.robotics.rcx.legos)
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| | Re: loading s/w
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(...) That's what I am doing. Markus. (25 years ago, 21-Apr-99, to lugnet.robotics.rcx.legos)
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| | Re: legOS Network Protocol
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(...) Hmm.. with a little hacking you could certainly detect logic errors. The main problem I think would be writing alternative C-Functions for the H8 assembler, which makes up legOS itself. You'd also need to create a simulator engine for legOS to (...) (25 years ago, 21-Apr-99, to lugnet.robotics.rcx.legos)
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| | Re: loading s/w
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(...) The first instruction (at 03ae) places the stack in on-chip memory, assuming RAME bit of SYSCR is at its initial value of 1. Why not make rom_reset() disable interrupts, then do its thing? That would be the safest thing to do. -Kekoa (25 years ago, 21-Apr-99, to lugnet.robotics.rcx.legos)
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| | Re: loading s/w
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(...) Well, if rom_reset() gets invoked near the end of your time slice, ROM has no time to reset the OCIA IRQ vector before the next timer tick. I'm not certain about the order in which ROM sets up data areas and IRQ vectors. legOS freely allocates (...) (25 years ago, 20-Apr-99, to lugnet.robotics.rcx.legos)
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| | Re: legOS Network Protocol
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(...) Assuming packets without large internal gaps, we could employ a timeout to wait for a packet transmission of unknown protocol type to end. At 2400 bps with 8E1 (LEGO, isn't it?), one data byte has 11 bits, so a space of 1.5*11/2400 s should be (...) (25 years ago, 20-Apr-99, to lugnet.robotics.rcx.legos)
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| | Re: Rotation sensor bug found
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(...) Excellent idea. This would yield the default settings dead-on. (...) Scaling isn't about the final output. The final output is already in the standard format. Scaling is about shifting the raw sensor values displayed by the firmware six digits (...) (25 years ago, 20-Apr-99, to lugnet.robotics.rcx.legos)
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| | Re: legOS Network Protocol
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(...) Yes this will be a datagram only protocol for the time being. The LNP will allow us to do things like debugging and remote control. I have also invisioned something like a "shell" running on the legOS that you could either "telnet" in to or (...) (25 years ago, 20-Apr-99, to lugnet.robotics.rcx.legos)
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| | Re: Rotation sensor bug found
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(...) Why doesn't somebody finish up the decoding of the ROM, specifically the routine at 14c0. This routine takes the raw sensor samples and converts them to usable values, including handling the temperature and rotation sensors. The standard (...) (25 years ago, 20-Apr-99, to lugnet.robotics.rcx.legos)
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| | Re: legOS Network Protocol
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(...) From what little I remember about the Lego protocol, here are some thoughts. *) On reception, some Lego packets may contain data which look like the beginning of a legOS native protocol frame. Most likely, the checksum would fail (once enough (...) (25 years ago, 20-Apr-99, to lugnet.robotics.rcx.legos)
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