 | | Using NXT Port 4 EIA-485
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Hi, is there currently any software-support (pbLua, NXT-G, NXJ) for NXT Port4 highspeed serial communication (EIA-485) ? This port can be used for connecting some new hardware (camera, SD-Card-storage) to the NXT... Thanks for more informations Bye (...) (18 years ago, 7-Apr-07, to lugnet.robotics.nxt)
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| | Re: Using NXT Port 4 EIA-485
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(...) As far as I know, there isn't any support for this interface in either the standard firmware or any of the other third party firmware implementations. The interface runs at 921,600 bps so it will be fast enough to be really useful. I am hoping (...) (18 years ago, 8-Apr-07, to lugnet.robotics.nxt)
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| | RE: Using NXT Port 4 EIA-485
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I've looked at implementing an interface for RobotC, but I've always struggled with why bother since there are no applications that connect to it. I wish LEGO had implemented an option to provide a logic level "RS-232" UART on port four. Yes, I (...) (18 years ago, 8-Apr-07, to lugnet.robotics.nxt, lugnet.robotics.nxt.nxthacking)
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| | Re: Using NXT Port 4 EIA-485
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(...) What is not supported about this port in the standard NXT firmware? You can read from it and write to it using the IOMapRead and IOMapWrite syscall functions. Looking at the firmware source code it certainly looks like everything is setup to (...) (18 years ago, 9-Apr-07, to lugnet.robotics.nxt)
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| | Re: Using NXT Port 4 EIA-485
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(...) Do you think it is possible to read/write binary and ascii data to this device or is there a special protocol neccessary ? What about bitrate of EIA-485 device ? Is it possible to adjust bitrate to anything more usable (9600, 38400, 115200) ? (...) (18 years ago, 9-Apr-07, to lugnet.robotics.nxt)
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| | Re: Using NXT Port 4 EIA-485
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(...) Hi John. I must have misunderstood something I was told a while back which went along the lines of "there isn't enough time to implement support for this feature". Perhaps there was some time after all ;) Do you know how large the OutBuf and (...) (18 years ago, 9-Apr-07, to lugnet.robotics.nxt)
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| | Re: Using NXT Port 4 EIA-485
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(...) Hi, halfduplex is not the problem when connecting the NXT to an external MCU. My problem is the bitrate of 921,6 kbits/s. Simple cheap MCU like ATMega didn't support this bitrate (as far as I know). To add an external devices (e.g MCU+SD-Card (...) (18 years ago, 9-Apr-07, to lugnet.robotics.nxt, lugnet.robotics.nxt.nxthacking)
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| | Re: Using NXT Port 4 EIA-485
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Hi Christian, (...) the RS-485 interface is directly connected to the AT91SAM7S USART, so you can choose the bit rate quite freely. (...) No, it is not necessary, P-Net is just a field bus which seems to be popular in Denmark, there are others which (...) (18 years ago, 10-Apr-07, to lugnet.robotics.nxt, lugnet.robotics.nxt.nxthacking)
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| | Re: Using NXT Port 4 EIA-485
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(...) Hi Juergen, Yes, I found this night the entries at Lego-Source-Code... and no line about P-NET-Protocol... My first thought was to implement a simple p-net-node at own MCU, but now I can try my own communication from NXT (master) to external (...) (18 years ago, 10-Apr-07, to lugnet.robotics.nxt, lugnet.robotics.nxt.nxthacking)
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| | Re: Using NXT Port 4 EIA-485
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(...) They are tiny. #define SIZE_OF_HSBUF 128 typedef struct { UBYTE Buf[SIZE_OF_HSBUF]; UBYTE InPtr; UBYTE OutPtr; UBYTE Spare1; UBYTE Spare2; }HSBUF; // HI Speed related entries HSBUF HsInBuf; HSBUF HsOutBuf; The IOMap hi speed buffer is copied (...) (18 years ago, 10-Apr-07, to lugnet.robotics.nxt)
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| | Re: Using NXT Port 4 EIA-485
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(...) Christian, There is currently no direct support for this in pbLua, but it's not too hard to add. The HighSpeed port is port 4, and it has basically 3 wires that control how it works. PA4/5 are the RX and TX to UART0 right on the ARM PA7 is RTS (...) (18 years ago, 16-Apr-07, to lugnet.robotics.nxt)
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| | Re: Using NXT Port 4 EIA-485
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(...) Ralph, I'm using an ATMega8 as frontend processor between NXT and SD-Card. Step1: NXT===>I2C===>ATMega...==>SD-Card Disadvantage: Very low speed (9600) Step2: NXT===>EIA-485===>AT...==>SD-Card This should work in an easy way, FAT-Support for (...) (18 years ago, 17-Apr-07, to lugnet.robotics.nxt)
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| | Re: Using NXT Port 4 EIA-485
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ReHi Ralph, (...) I'd like to have some address information for device number added (can be done at a higher layer ?)... EIA-485-Hardwareconcept allows to handle more than one target :D ID0: Master (NXT) ID1: SD ID2: Camera :D ... (...) I hope we (...) (18 years ago, 17-Apr-07, to lugnet.robotics.nxt)
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| | Re: Using NXT Port 4 EIA-485
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(...) Great idea Christian! What kind of API do you need to make this work? I think these might get things started: nxt.RS485SetParam( speed, parity, databits, stopbits ) nxt.RS485SendData( string, bytes ) string = nxt.RS485GetData( bytes ) status = (...) (18 years ago, 17-Apr-07, to lugnet.robotics.nxt)
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| | Re: Using NXT Port 4 EIA-485
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(...) Does anybody have an NXC program that demonstrates the use of RS485 communications? (17 years ago, 25-May-07, to lugnet.robotics.nxt, lugnet.robotics.nxt.nxthacking)
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