**** BEGIN LOGGING AT Wed Oct 26 02:59:58 2005 Oct 26 18:01:52 hey Oct 26 18:02:00 <[g2]> welcome Oct 26 18:02:31 <[g2]> ep1220 is just finishing up a JTAG board Oct 26 18:02:52 <[g2]> so an 8 line USB FXS adapter eh ? Oct 26 18:03:07 <[g2]> FXS is customer phone line right ? Oct 26 18:03:23 the internal, house side Oct 26 18:03:40 <[g2]> right Oct 26 18:04:12 <[g2]> so 8 RJ11s Oct 26 18:04:41 yeah Oct 26 18:04:54 <[g2]> lemme guess asterisk in a box Oct 26 18:05:08 it's nothing more then a glorified DAC with some extra stuff for ringing Oct 26 18:05:52 asterisk box does all the hard work Oct 26 18:06:08 <[g2]> I would think a cheap DSP handle the 8 lines no ? Oct 26 18:06:39 it's based around a PIC device Oct 26 18:06:52 <[g2]> ah 8 PICs ? Oct 26 18:07:28 <[g2]> are you just thinking usb 1.1 and that's way the 8 limit ? Oct 26 18:08:04 no 1 PIC with 8 inbuilt ADC and an external SPI connected DAC Oct 26 18:08:18 the 8 way limit is because I ran out of ports on the PIC Oct 26 18:09:52 <[g2]> so are the usb side are you running isochronous data ? Oct 26 18:10:11 <[g2]> and interrupts ? Oct 26 18:11:18 it uses 8 intersil SLICs with a PIC 18F4455 Oct 26 18:11:55 i've yet to actually produce a physical board - but the interface should be very simple in theory Oct 26 18:12:15 I have an 18F4455 I was looking to use somewhere :) Oct 26 18:12:23 <[g2]> how easy are the SLICs to get ahold of ? Oct 26 18:12:25 <[g2]> hey ka6sox Oct 26 18:12:36 <[g2]> mithro is interested in doing open hardware Oct 26 18:12:42 18F4455s are very cool Oct 26 18:12:42 excellent! Oct 26 18:12:51 the inbuilt USB is really handy Oct 26 18:13:14 I have 3 samples and looking to use it for a SCADA application Oct 26 18:13:26 [g2], cool..thats a nice thing. Oct 26 18:13:52 basically i'm after doing something a bit simpler before i actually try and get out this other device Oct 26 18:14:01 <[g2]> mithro ka6sox builds boards Oct 26 18:14:46 okay I saw talk about what looks like a device for Asterisk Oct 26 18:15:03 ka6sox: want me to start from the beginning? Oct 26 18:15:28 ya...sounds interesting from what I saw :) Oct 26 18:16:15 okay - i decided that FXS devices are too expensive Oct 26 18:16:30 yep Oct 26 18:16:35 so I wanted a cheap replacement Oct 26 18:17:21 <[g2]> mithro is this for asterisk ? Oct 26 18:17:44 hence i designed a 8 line FXS USB device which should be able to be built for under $50 US Oct 26 18:17:50 excellent Oct 26 18:17:55 however i have never done hardware before Oct 26 18:18:18 [g2], we could use this on a SLUG....excellent Oct 26 18:18:31 so I'm bound to have made quite a few "beginner" mistakes Oct 26 18:18:31 <[g2]> ka6sox or a loft :) Oct 26 18:18:48 do you have design tools (EDA stuffs)? Oct 26 18:19:08 the device is pretty underpowered - most of the processing has to be done by Asterisk Oct 26 18:19:30 mithro, its only going to be a USB A/D D/A converter Oct 26 18:19:55 ka6sox: basically a glorified USB A/D D/A Oct 26 18:19:58 yep Oct 26 18:20:03 * [g2] still wonders why not use a DSP Oct 26 18:20:08 cost. Oct 26 18:20:16 [g2]: programming expertise Oct 26 18:20:23 his goal is <$50 Oct 26 18:20:25 <[g2]> hey they were only $5 years ago Oct 26 18:20:38 i could use a TI DSP which would cost only a little more then the PIC Oct 26 18:20:45 but its all the glue and other stuffs that drives cost. Oct 26 18:20:54 but i hate DSP programming, no free tools Oct 26 18:21:00 <[g2]> most of the DSPs support glueless Oct 26 18:21:31 glueless? Oct 26 18:21:47 i'm more comfortable with PICs personally Oct 26 18:22:01 there are some Pic DSP devices. Oct 26 18:22:23 (co processor like devices) Oct 26 18:22:53 yeah Oct 26 18:23:08 start with a PIC - replace with a DSP at a later date Oct 26 18:23:38 <[g2]> I know a guy that's been doing dsp stuff forever Oct 26 18:23:46 most sample rates are up around 8khz (64kb sample rate) Oct 26 18:24:05 in fact the TI DSP removes the requirement for most of the chips Oct 26 18:24:10 but they are impossible to hand solder Oct 26 18:24:35 yep Oct 26 18:24:42 so... Oct 26 18:24:52 basically i need a simple project to get my feet wet Oct 26 18:24:56 <[g2]> well most things are smt right ? Oct 26 18:25:06 [g2]: yeah everything is SMT Oct 26 18:25:22 through hole stuff takes up to much space Oct 26 18:25:56 plus goes through the board making it hard to trace stuff with only two sides Oct 26 18:26:03 <[g2]> I think there's a place that does boards for $5 a square inch on the first run Oct 26 18:26:34 <[g2]> I've heard they do it for $2.50 of you know what your doing after a run or two Oct 26 18:26:43 cheapest i've seen is $33 boards Oct 26 18:26:59 * mithro hates soldering :P Oct 26 18:27:06 <[g2]> I'd imagine this would be a small board Oct 26 18:27:43 [g2]: do you have Cadsoft eagle? Oct 26 18:28:17 <[g2]> no I don't... I'm not doing a lot of layout yet, but that'll be next Oct 26 18:29:01 i can send you the prototype PCB layout if you wanted to have a look see Oct 26 18:29:04 <[g2]> I'd like to do a couple small boards first before a full system board Oct 26 18:30:20 <[g2]> mithro I think there's the design and then the layout Oct 26 18:30:35 hrm? Oct 26 18:31:24 the current board size is "100 x 80 mm (4 x 3.2 inches)" Oct 26 18:32:16 so... Oct 26 18:32:17 <[g2]> would you need to go 8 ports out of the box ? Oct 26 18:32:22 thats fairly significant Oct 26 18:32:27 <[g2]> what about 2 Oct 26 18:32:28 100X80mm Oct 26 18:32:57 the SLIC chips are pretty big and I need 8 off em Oct 26 18:33:03 <[g2]> right the ixp42x board is 4x6 Oct 26 18:33:08 <[g2]> twice the size Oct 26 18:33:18 i could go with the smaller version Oct 26 18:33:26 but i can't assemble them then Oct 26 18:33:32 <[g2]> but has a 32-bit 533Mhz processor, flash, memory, two ethernets, power ..... Oct 26 18:34:04 8 rj-11s take up quite a bit of space too Oct 26 18:34:40 ya. Oct 26 18:36:15 external connections: 8 rj-11s, power connector and a USB connector Oct 26 18:36:25 <[g2]> ah another hw hacker joins the frey Oct 26 18:36:55 chips: 1xPIC 18F4455, 8xIntersil SLICs, 1 Maxim port extender, 1 TI DAC Oct 26 18:37:11 but as I said, it's a rather complicated project to start with Oct 26 18:37:24 <[g2]> complicated is a relative term Oct 26 18:37:39 what is the Intersil part #? Oct 26 18:37:44 [g2]: compared to a 8 led light flasher :P Oct 26 18:38:14 HC55185 Oct 26 18:39:20 don't downplay the importance of Flashy LED's Oct 26 18:39:26 the closest i've come to hardware before now is a breadborded audio amplifier i built in PED and a few self assemble electronics kits from Dick smiths electronics Oct 26 18:39:42 I can program a PIC pretty well Oct 26 18:40:52 so i was thinking something a long the lines of a PIC+DECT chip for a simple DECT->IP bridge Oct 26 18:41:24 with only USB1.1 we have to be careful that the overhead and latency don't become an issue. Oct 26 18:42:05 the DAC might be very unforgiving of not having data when it needs it. Oct 26 18:44:46 true Oct 26 18:44:56 so.... Oct 26 18:45:42 whats are you people recommending? how should I start? Oct 26 18:46:02 when do you have to have this finished? Oct 26 18:46:39 etenity Oct 26 18:46:48 * mithro is a student doing this in my free time Oct 26 18:47:42 okay so this isn't for a class? Oct 26 18:47:46 nope Oct 26 18:48:39 well...you have some good ideas there yourself... Oct 26 18:48:53 the parts you have chosen are pretty nice. Oct 26 18:49:45 i could have possibly done it for a final year project next year, but my failure of some course has kind of thrown next year into a bit of chaos Oct 26 18:52:01 i would still like to try something a bit simpliar to start with Oct 26 18:52:20 my software skills are pretty good - my hardware skills are still developing Oct 26 18:55:36 k Oct 26 18:56:31 we used to use 2048kb/s as our loops in the old days..but they were syncronus Oct 26 18:58:03 ? Oct 26 18:58:28 I like the flashy light. Oct 26 18:59:32 Mmmmm Noodles... Oct 26 19:00:23 * ka6sox remembers telephone back in the OLD days...like 25yrs ago. Oct 26 19:00:30 today we have IP phone. Oct 26 19:15:14 mithro, all of us are here a lot...so pop on in here when you can. Oct 26 19:51:55 okay **** ENDING LOGGING AT Thu Oct 27 02:59:56 2005