Replying in a batch to minimise list noise... On Sep 3, 2006, at 2:46 PM, BillW wrote: >>> You have defined OSC 8; is the crystal actually 8? >> >> So my colleague assures me. I'm not using an external crystal - >> there's a default oscillator on the board, isn't there? > > WHICH board are you talking about? It's a custom board, developed by someone who is no longer associated with us. It has a port for in-circuit programming, a port for serial comms (not connected to the hardware serial, and used for loading new data at runtime) and 8 HEXFETs controlling output. It has no external crystal - there is room for one, but it would be nice to avoid soldering 300 on. On 9/4/06, Jan-Erik Soderholm wrote: > Mark Wotton wrote : > > > define OSC 8 > > This might be obviouse, but it's worth to be mentioned > anyway... > > Defining OSC to some value does NOT change the speed > of the PIC oscillator as such, just the speed the BasicPro > compiler THINKS that the PIC is running in. Yes, I understand that. I'm perfectly happy with an 8 MHz oscillator, I just want to make sure that PicBasic is too so that the SERIN command works properly. > Now, the 2455 (or any of the other USB PICs) might not > be the best "beginners-PIC". Just the oscillator block is much > more complex then on a "standard" PIC18. It took me a great > time of reading to "get it"... You might be right. Unfortunately, we have 300 of them and a fixed and ever-looming deadline: alternatives are thin on the ground. (Given that we never use the USB, I'm not at all sure why the choice was made in the first place - the guy who specified and designed it is long gone and incommunicado.) > Finaly, is Basic realy optimum to write USB firmware (I guess > you're ging to use the USB interface, right ?) ? > I'm not saying that it can't be done, but most examples are > in C if I'm not wrong. I'm not actually using USB on this board. I'm not at all dogmatic about what language to use, it's just what was set up when I arrived. On 9/4/06, peter green wrote: > > > So my colleague assures me. I'm not using an external crystal - > > there's a default oscillator on the board, isn't there? > > (Again, forgive me my naivete, I'm new to this.) > if you are reffering to the pics internal oscilator then > yes there is > yes it is 8mhz > no it can't be used with the PLL (unlike on other PIC18 chips) > no it can't be used for usb. > and if you wan't to use it you need to select intosc. > > if you are reffering to a crystal on the development board you are using > then we need to know what development board that is. Ok. I tried selecting intosc in the .inc file, but it didn't seem to make any difference to the slowdown: I'll try with a simpler assembly program and see how I go. Mark -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist