tomcody Posted December 10, 2005 Report Share Posted December 10, 2005 in my country apparently there is no 18F452 :-\, but there is 18F4680, and my questions are: Can I use a 18F4680 instead of 18F452? ???, What changes I have to do to the ASM code? ??? (I don't have kwonledge of ASM, but I know C, that can help me ...). Thanks. :) Quote Link to comment Share on other sites More sharing options...
Jidis Posted December 10, 2005 Report Share Posted December 10, 2005 I'm no expert, but it seems like if all the pinouts and power requirements were the same, maybe you could specify that chip to MPASM and try to compile to see if it complains. ??? (unless there are other speeds or specs. involved here)-Good Luck Quote Link to comment Share on other sites More sharing options...
raphael Posted December 10, 2005 Report Share Posted December 10, 2005 Maybe recompiling is enough (I don`t think so...). At least you would have to change some parts of the source. Look at the changes Thorsten has made for the 18F4620.But even a recompiled version of MIOS will not work if the 18F4680 has the same silicon bug as Thorsten has found during the 18F4620 development and which is still not fixed by microchip :(http://www.midibox.org/forum/index.php?topic=4838.0So, better to go for a 18F452. Where do you live? Maybe you can buy 18F452s at Mikes or SmashTV's shop.Raphael Quote Link to comment Share on other sites More sharing options...
tomcody Posted December 10, 2005 Author Report Share Posted December 10, 2005 Thanks for your attention to my question, I hope that the 18F4680 does not have the same problem of the 18F4620, I was searched about this in microchip.com but I don't find anything, I will post in http://www.midibox.org/forum/index.php?topic=4838.0 about this doubt. I'm a little distrusted about the shipping, it could spoil or something. The advantage is that on SmashTV's Store they can send it me programmed with the bootstrap loader, and the cost are the relatively the same: buy on SmashTV's Store, including shipping, etc; or buy the 18F4680 in my country (Chile, South America) ... well, I will think deeply in this before do something, I will be glad if you post any other advice, thanks again to you raphael and Jidis. Quote Link to comment Share on other sites More sharing options...
TK. Posted December 10, 2005 Report Share Posted December 10, 2005 Just one month ago I tried some fresh 18F4620 and 18F4520 samples - they still have the EUSART bug. In the meantime it turned out, that not only the transmitter is affected, but also the receiver (sometimes it gets a frame error).Especially the fails on the 18F4520 prove that this is no configuration problem, since this device is 1:1 hard-and software compatible to the 18F452, where the Bootloader and MIOS are running pretty stable.I gave it up to inform the Microchip support about this issue. I tried it three times, each time I was handled like a newbie, or they confirmed the bug and gave me suggestions which are just totally useless. E.g. one suggestion was, that the transmitting routine has to turn off and on the serial transceiver after each transfer - with the result, that continuous back-to-back transfers are not possible anymore, and that incoming data will be corrupted (no full-duplex anymore). So - don't buy any PIC which includes the EUSART, it won't work with MIDI. Once Microchip releases new chip revisions, I will try it again.Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
tomcody Posted December 13, 2005 Author Report Share Posted December 13, 2005 Thanks for reply, Thorsten; fortunately I found a store here in Chile (www.victronics.cl) that have the 18F452 !!! ;D , I just have to wait the stock refill, thanks everybody!!! ;D ;D ;D ;D ;D . Quote Link to comment Share on other sites More sharing options...
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