 | | Re: pbLua PCF8574
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| (...) Hi Ralph, we are using this code: collectgarbage( "setpause", 110 ); function setupI2C(port) nxt.InputSetType(port,2) nxt.InputSetDir(port,1,1) nxt.InputSetState(port,1,1) nxt.I2CTimer(3) nxt.I2CInitPins(port) end function ReadPCF(port) (...) (18 years ago, 19-May-07, to lugnet.robotics.nxt, lugnet.robotics.nxt.nxthacking)
| | | | | Re: pbLua PCF8574 SOLVED
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| (...) Hi, we solved the problem... Lego-Firmware has own brain and handle read/write with own mechanisms ;-( The last read/write bit is handled automatically by lowlevel routines. Reading the same address like writing solves the problem. (...) (18 years ago, 21-May-07, to lugnet.robotics.nxt, lugnet.robotics.nxt.nxthacking)
| | | | | Re: pbLua PCF8574 SOLVED ?
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| (...) Hi, or was it a quirk at my brain to address the i2c-read-address and hope to receive usefull data ? Currently it works for me when using allways the i2c-write address... Are the any demos or samples for NXC, using the PCF8574 ? 1. setting (...) (18 years ago, 21-May-07, to lugnet.robotics.nxt, lugnet.robotics.nxt.nxthacking)
| | | | | RE: pbLua PCF8574 SOLVED ?
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| (...) This is the excepted behavior. When you want to read from I2C device, the NXT firmware first sends a write message to load the internal index "pointer" for the I2C device and then sends a read message that will read the requested number of (...) (18 years ago, 21-May-07, to lugnet.robotics.nxt, lugnet.robotics.nxt.nxthacking)
| | | | | Re: pbLua PCF8574 SOLVED !
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| (...) Hi Dick, your answer solves my knot :D It's a NXT specific behaviour and all alternatives NXT-OSes which uses original Lego-Source-Lowlevel routines have this feature ? Thanks for your answer Bye Christian (18 years ago, 21-May-07, to lugnet.robotics.nxt, lugnet.robotics.nxt.nxthacking)
| | | | | Re: pbLua PCF8574 SOLVED !
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| (...) Let me say thanks to Dick as well. I think that the NXT firmware does what's called a repeat start in the I2C definition... Here's the part in the I2C spec that is required: (URL) And with pictures: (URL) Hope this helps... Ralph (18 years ago, 21-May-07, to lugnet.robotics.nxt, lugnet.robotics.nxt.nxthacking)
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