Search found 11 matches
- Mon Oct 05, 2009 3:47 pm
- Forum: User Modules
- Topic: MAX7456 OSD video overlay code
- Replies: 10
- Views: 15666
Hi Leo, Yes, the character set is a bit strange on the MAX7456, but I got around this by using the 'GetCharCodeFromTable()' routine. The font files on the Arduino forum look like an easy way to get around the problem! On my system, I have defined some custom characters using the MCM and MDM utilitie...
- Wed Sep 30, 2009 10:26 am
- Forum: User Modules
- Topic: MAX7456 OSD video overlay code
- Replies: 10
- Views: 15666
Hi Leo, I got the ICs as samples directly from Maxim and soldered one down to a SMD-to-DIL adaptor and I then used a good old fashioned breadboard to do the prototyping as there really aren't very many connections to make. I've since made this into a more permanent design using stripboard and I may ...
- Wed Sep 02, 2009 10:38 pm
- Forum: Compiler
- Topic: 18F8722 Extended Microcontroller mode...
- Replies: 12
- Views: 9385
Hi Octal, Ok - I'm really not trying to start an argument with you, and I think we may be misinterpreting each others responses :oops: . I completely agree with what you're saying that on-chip RAM is accessed one way, and off-chip SRAM is accessed by table writes and table reads. They are different,...
- Wed Sep 02, 2009 4:51 pm
- Forum: Compiler
- Topic: 18F8722 Extended Microcontroller mode...
- Replies: 12
- Views: 9385
Hi RocketBob, It doesn't matter to the PIC whether the external memory is FLASH or SRAM contrary to what has been mentioned above: user has to know, for example, that he still cant use it as normal ram I've done this loads of times using the MCC18 compiler and it works perfectly. However, I still ha...
- Mon Jun 29, 2009 3:02 pm
- Forum: User Modules
- Topic: MAX7456 OSD video overlay code
- Replies: 10
- Views: 15666
MAX7456 OSD video overlay code
I've been playing around with the MAX7456 OSD video IC in a project to overlay GPS data onto a video stream, and I'd like to share the beta code with other users. With a bit of refinement maybe this could be made into a fully functional module? So far it allows you to write strings of text to any po...
- Tue Mar 17, 2009 12:46 pm
- Forum: Modules
- Topic: usart SetBaudrate issue
- Replies: 2
- Views: 4201
- Fri Jan 09, 2009 9:34 am
- Forum: Compiler
- Topic: ADC in interrupt
- Replies: 4
- Views: 3008
I'm not sure how it would be possible to cause an interrupt on a specific ADC value. However, if you want to trigger an interrupt at a specific analogue voltage level then some PICs have a built in comparator that would do the job. Failing that, an external window comparator with the output fed into...
- Thu Jan 08, 2009 12:12 am
- Forum: Compiler
- Topic: 18F8722 Extended Microcontroller mode...
- Replies: 12
- Views: 9385
Hi Octal, Thanks for your reply - I guess it makes sense that Swordfish doesn't handle this scenario since it's not a particularly common thing to need to do (even amongst users of other PIC compilers). It's a bit of a shame though... :cry: However, what really appeals to me about Swordfish so far (...
- Wed Jan 07, 2009 5:43 pm
- Forum: Compiler
- Topic: 18F8722 Extended Microcontroller mode...
- Replies: 12
- Views: 9385
Hi Steve, I've used extended mode for a couple of projects now - basically you just sacrifice a bunch of IO pins and you get a multiplexed data and address bus. It's then fairly trivial to hang external RAM or FLASH from these, or just to memory map the entire project. I use this feature on an 18F87...
- Wed Jan 07, 2009 3:16 pm
- Forum: Compiler
- Topic: 18F8722 Extended Microcontroller mode...
- Replies: 12
- Views: 9385
Ok, I've made a little progress, but it's not ideal. I can declare the variable as an absolute, ie: dim XRamVar as byte absolute $80000 which seems to work from examination of the LST file. However, what I'd ideally like to do would be to specify a starting address to put the following variables, li...
- Tue Jan 06, 2009 9:28 pm
- Forum: Compiler
- Topic: 18F8722 Extended Microcontroller mode...
- Replies: 12
- Views: 9385
18F8722 Extended Microcontroller mode...
Hi, I'm on the brink of ordering the Swordfish compiler for a project I'm working on but I've got a quick question first: Does Swordfish allow you to access external RAM connected to an 18F8722 in extended microcontroller mode? I have a general purpose board made up with an extra 256K of RAM which I...