c0nsumer Posted April 27, 2006 Report Share Posted April 27, 2006 Due to an oversight on my part†, it appears that it would be most useful for me if I were to use a PIC18F4620 on a MIDIbox SID implementation I am working on. While I understand that the firmware is still beta, can any of you see any reason why I shouldn't use a PIC18F4620 instead of the 'normal' PIC18F452?The device I am putting together is a simple MIDI-controlled SID-based sound module. It's the MB_CORE, MB_SID, and MB_LTC modules stripped down to just what I need and squished on to one board.So, do you all think the PIC18F4620 would work fine for my application?Thanks very much...-Steve†That oversight being, I built a DIP40 adapter for my PICkit2 and overlooked the PICkit2's lack of support for the PIC18F452. (I must have seen the PIC18F452X family support and thought that also applied to the PIC18F452... But I digress.) I've also included ICSP support in my board design, but (obviously) this will be unusable with the PIC18F452 and the PICkit2... Quote Link to comment Share on other sites More sharing options...
stryd_one Posted April 27, 2006 Report Share Posted April 27, 2006 You'd be a guinea pig for sure... You'd be testing out a lot of additional stuff above and beyond your normal application. If you're really familiar with programming PICs you'll probably be fine, but there will surely be extra work.How much was the programmer? I might buy it from you if you need to offload it... Quote Link to comment Share on other sites More sharing options...
c0nsumer Posted April 27, 2006 Author Report Share Posted April 27, 2006 You'd be a guinea pig for sure... You'd be testing out a lot of additional stuff above and beyond your normal application. If you're really familiar with programming PICs you'll probably be fine, but there will surely be extra work.How much was the programmer? I might buy it from you if you need to offload it...Thanks for the offer, but it's only $50 for the programmer and a dev board. I've actually used it quite a few times, and programming PICs isn't the problem. It's just my... Well... Complete screwup. heh. The reason I put the ICSP on the MIDIbox SID PCB design I'm working on was because I've got the programmer, and I don't want to have to worry about flashing it via MIDI, or what to do if that fails. (If you'd like to see the board layout and schematic as of this afternoon, it can be seen here. I'll share the EAGLE files if you'd like...)Maybe what I'm asking is if there is any reason why I shouldn't use the PIC18F4620?-SteveUPDATE: I should add that if you want one of the PICkit2 Programmers, you can get them from Digi-Key for that price. It's part of the Microchip PICkit2 development kit thing. It's a nice programmer which is completely open source / documentation. Quote Link to comment Share on other sites More sharing options...
stryd_one Posted April 27, 2006 Report Share Posted April 27, 2006 OK let me re-word what I said....When I said "Programming PICs" I meant writing code for them, not flashing them.What's your problem with uploading firmware by MIDI? Seems to me to be far easier, scalable, blah blah blah...I dunno, it sounds like you are thinking about taking a much harder path (using the 4620) in order to make an inferior product. I think you're nuts ;)Edit: Staight answer to your question: Yes, there are lots of reasons not to use the 4620. Quote Link to comment Share on other sites More sharing options...
c0nsumer Posted April 27, 2006 Author Report Share Posted April 27, 2006 OK let me re-word what I said....When I said "Programming PICs" I meant writing code for them, not flashing them.What's your problem with uploading firmware by MIDI? Seems to me to be far easier, scalable, blah blah blah...I'm not that familiar with it, but I've done some basic stuff with the dev hardware which came with the PICkit2. I'm hoping to use this for playing around and learning... That's my worry about flashing via MIDI. If I break the bootloader, I'm screwed unless there's an easy way to flash the PIC.I dunno, it sounds like you are thinking about taking a much harder path (using the 4620) in order to make an inferior product. I think you're nuts ;)Edit: Staight answer to your question: Yes, there are lots of reasons not to use the 4620.I guess what I'm not understanding is why it's a harder path. In the v1.9 portion of the MIOS changelog there seems to be a workaround for the current hardware bug in the 4620. Or am I misreading that?Or maybe I should just leave the ICSP stuff in place before sending the boards off to be made, then it can be used once the 4620 is better supported, or I've got a better way to program the 452? (I'll probably just assemble a parallel port programmer with a header on it similar to the PICkit2 one.) Quote Link to comment Share on other sites More sharing options...
raphael Posted April 27, 2006 Report Share Posted April 27, 2006 I guess what I'm not understanding is why it's a harder path. In the v1.9 portion of the MIOS changelog there seems to be a workaround for the current hardware bug in the 4620. Or am I misreading that?The workaround is the MBHP_IIC_MIDI module (http://www.ucapps.de/mbhp_iic_midi.html) ;DThere is no known software workaround for the buggy EUSART. So to use the Midi out you,ll have to add a IIC module to your design. Quote Link to comment Share on other sites More sharing options...
c0nsumer Posted April 27, 2006 Author Report Share Posted April 27, 2006 The workaround is the MBHP_IIC_MIDI module (http://www.ucapps.de/mbhp_iic_midi.html) ;DThere is no known software workaround for the buggy EUSART. So to use the Midi out you,ll have to add a IIC module to your design.Ah, thanks for clearning that up. I really did read it wrong... Hrm.So, it sounds like at this point I can either use my existing design with a PIC18F452, or add the MBHP_IIC and use the newer PIC. Adding the IIC module doesn't sound too bad. Since it can be used to provide MIDI IN/OUT LEDs I could just replace the stripped down LTC portion of the board with that.Or, I can go with the existing design and just put together a different PIC programmer.Given the choice between both (since I'm still laying out the board) which would you go with: A PIC18F4620 + IIC module, or a PIC18F452. It seems to me like the PIC18F4620 might be a bit more useful down the line? Quote Link to comment Share on other sites More sharing options...
Synapsys Posted April 27, 2006 Report Share Posted April 27, 2006 Given the choice between both (since I'm still laying out the board) which would you go with: A PIC18F4620 + IIC module, or a PIC18F452. It seems to me like the PIC18F4620 might be a bit more useful down the line?The IIC_MIDI module functionally resolves the EUSART bug. In fact, all you really need is the 'output only' version of the IIC_MIDI module to overcome the EUSART bug. You will, of course, also need to use MIOS V1.9 in order to support the IIC_MIDI module. The 18F4620 chip provides the advantage of more flash and more ram thus allowing for future additional features to be added to all MIDIbox applications.Having used the IIC_MIDI module for some weeks now with great success I would go with the 18F4620 for all new MIDIbox projects ;)Regards,Synapsys Quote Link to comment Share on other sites More sharing options...
c0nsumer Posted April 27, 2006 Author Report Share Posted April 27, 2006 The IIC_MIDI module functionally resolves the EUSART bug. In fact, all you really need is the 'output only' version of the IIC_MIDI module to overcome the EUSART bug. You will, of course, also need to use MIOS V1.9 in order to support the IIC_MIDI module. The 18F4620 chip provides the advantage of more flash and more ram thus allowing for future additional features to be added to all MIDIbox applications.Having used the IIC_MIDI module for some weeks now with great success I would go with the 18F4620 for all new MIDIbox projects ;)Hmm, thanks. :D That's good to hear... It would also likely be quite a bit easier for me to just use the 18F4620. No need to build another PIC programmer, only a mild design change to make to the board. I think I'll get to work laying out the board with the IIC_MIDI module for both MIDI IN and OUT. I don't think this will be too great of a change.(I need to nudge some parts around based on some measurements I made of the actual enclosure for the board, anyway...)Thanks very much. :)-Steve Quote Link to comment Share on other sites More sharing options...
c0nsumer Posted April 27, 2006 Author Report Share Posted April 27, 2006 Hrm, now this is a bit confusing... The PIC16F88 is listed as a device in the 'PICkit 2.dvs' file, but I can't find any documentation stating that it actually works. Regardless, the new layout is done.Mind if I ask how you all programmed your PIC16F88s? I can't try it myself with the PICkit2 until I get one... Quote Link to comment Share on other sites More sharing options...
moebius Posted April 27, 2006 Report Share Posted April 27, 2006 Not that I've programmed any, but maybe with PIC Burner and the programming adapter found from the IIC MIDI Module page?M Quote Link to comment Share on other sites More sharing options...
c0nsumer Posted April 27, 2006 Author Report Share Posted April 27, 2006 Not that I've programmed any, but maybe with PIC Burner and the programming adapter found from the IIC MIDI Module page?That'll work, I just don't have one yet. I'm actually in the middle of laying out a board for it now. I'm just going to put 40-pin and 20-pin sockets on the same board, though. That way I can do both chips (and other PICs) with the same board. Quote Link to comment Share on other sites More sharing options...
Synapsys Posted April 27, 2006 Report Share Posted April 27, 2006 I use the ICD2 module to do all my PIC programming. Since the 16F88 requires 13.1v for the programming voltage the PICkit2 may or may not work, I don't know.If you run into a road block because you can't program the 16F88 send me a PM and we'll work out a way to get one done for you.Regards,SynapsysI'm just going to put 40-pin and 20-pin sockets on the same board, though. That way I can do both chips (and other PICs) with the same board. P.S. Keep in mind that the 16F88 is an 18 pin chip when laying out your programmer board ;) Quote Link to comment Share on other sites More sharing options...
c0nsumer Posted April 27, 2006 Author Report Share Posted April 27, 2006 I use the ICD2 module to do all my PIC programming. Since the 16F88 requires 13.1v for the programming voltage the PICkit2 may or may not work, I don't know.If you run into a road block because you can't program the 16F88 send me a PM and we'll work out a way to get one done for you.I just can't afford one of those for the amount of PIC work I currently do. :\ Thanks very much for the offer. I'll let you know... The other problem is I'll need 5-6 chips if I go this route... I'm making two of these for me, and three for friends.P.S. Keep in mind that the 16F88 is an 18 pin chip when laying out your programmer board ;)Hmm, I was planning on making a 20-pin socket like the one on the PICkit2, but after further investigation, it seems that the demo 16F690 isn't pin-compatible. I think instead I'll just stick with an 18-pin on the board specifically for the 16F688. I'll also throw a 1x6 header on there like the Microchip one, that way I can use this with other devices if need be, just by making a adapter board.By the way, given the choice, would you use a PIC18F452 or PIC18F4620 if you were making a stand-alone SID sound module? I'm still at the point where I can elect to use either. I've actually got the board layouts done for both the 18F452 w/ part of MBHP_LTC for MIDI LEDs and the PIC18F4620 w/ IIC_MIDI. Quote Link to comment Share on other sites More sharing options...
TK. Posted April 27, 2006 Report Share Posted April 27, 2006 By the way, given the choice, would you use a PIC18F452 or PIC18F4620 if you were making a stand-alone SID sound module? I'm still at the point where I can elect to use either. I've actually got the board layouts done for both the 18F452 w/ part of MBHP_LTC for MIDI LEDs and the PIC18F4620 w/ IIC_MIDI.if you want to use the features of MBSID V2 in future (see http://www.ucapps.de/midibox_sid_v2_wishlist.html), then a PIC18F4620 should be prefered, if you are planning your own firmware, I guess that you will be happy with the PIC18F452 for the first 1-2 years - and who knows, which pin compatible chips are available until then (the EUSART bug will be fixed sooner or later)Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
Synapsys Posted April 27, 2006 Report Share Posted April 27, 2006 Of course, I agree with TK on this issue. The additional cost of adding the 16F88 is rather trivial compared to the advantages afforded by the 18F4620.Regards,Synapsys Quote Link to comment Share on other sites More sharing options...
c0nsumer Posted April 27, 2006 Author Report Share Posted April 27, 2006 TK & Synapsys,Thanks very much for the input... At this point I'm most likely going to go with the PIC18F4620 and incorporate IIC_MIDI (without ID selection, obviously) on the board.I just need to finish laying out the board for the PIC burner and order some more parts before I keep going on the project.Thanks very much. :)-Steve Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.