21-09-2016, 05:34 PM
(This post was last modified: 21-09-2016, 05:38 PM by ppppenguin.)
This is essenitally identical to the modulator used in the Aurora SCRF. Darryl used an external master clock feed (from the FPGA) rather than a pair of 4MHz xtals. A CPU or FPGA based controller is needed to set the channel. The Aurora SCRF uses its FPGA, Frank has used a PIC. It's probably worth having a 3.5MHz sound trap ahead of the vision modulator.
Well done for a nice neat PCB. If I was doing a "one off" I'd probably do it dead bug style on a bit of copper clad board.
PS: Am I right in thinking that it's your article about a PIC based testcard generator in the new Bulletin? That's a lot of result for minimal resources. If I was doing something like that I think I'd store each pattern as a literal on an SD card and read it with a CPU or CPLD. Ample capacity for loads of patterns and redily programmable. I think Karen Orton has done something like this. It's also the basis of the Richard Russell generator and the ImoGen. The difference is that now you can get a lot of fast flash for virtually no money.
Well done for a nice neat PCB. If I was doing a "one off" I'd probably do it dead bug style on a bit of copper clad board.
PS: Am I right in thinking that it's your article about a PIC based testcard generator in the new Bulletin? That's a lot of result for minimal resources. If I was doing something like that I think I'd store each pattern as a literal on an SD card and read it with a CPU or CPLD. Ample capacity for loads of patterns and redily programmable. I think Karen Orton has done something like this. It's also the basis of the Richard Russell generator and the ImoGen. The difference is that now you can get a lot of fast flash for virtually no money.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
