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[15:13:49] <z0idb3rg> hi
[15:42:38] <hjohnson> so is the jtagice3 worth the investment?
[16:11:58] <megal0maniac> I love mine
[16:28:54] <Tom_itx> hjohnson, i suppose if you plan to do alot of debugging it would be
[16:29:20] <Tom_itx> i don't think most basic programming would warrant one
[16:32:10] <hjohnson> Tom_itx: eventually i'm going to be debugging a fairly complex xmega project (running FreeRTOS, multiple threads etc... so I think debugging is going to be critical)
[16:32:28] <Tom_itx> xmega uses PDI for debugging doesn't it?
[16:32:35] <Tom_itx> or do they also support jtag?
[16:33:03] <megal0maniac_afk> WHAT DID I MISS?
[16:33:08] <megal0maniac> jtagice3?
[16:33:10] <Tom_itx> megal0maniac alot
[16:33:12] <Tom_itx> :D
[16:33:21] <megal0maniac> It supports everything except high voltage stuff and TPI
[16:33:34] <Tom_itx> TPI is purely for the small tinys
[16:33:39] <Tom_itx> and some odd ones
[16:33:47] <Tom_itx> like the 20 and 40
[16:34:19] <megal0maniac> But they're adding more and more ARM devices to the supported list as well. Works with all atmegas, most attinys, and I think all AT32 UC3 and a lot of the SAM ARM chips
[16:34:30] <megal0maniac> zlog
[16:36:36] <megal0maniac> xmegas usually do both JTAG and PDI. But I don't know why you'd want JTAG when PDI is about as fast, less pins and doesn't override IO
[16:39:15] <megal0maniac> hjohnson: So if you've got the cash, definitely a worthwhile investment
[16:39:51] <megal0maniac> And lest we forget, the dragon is full of shit :D
[16:40:15] <hjohnson> the project I'm first working on is a tank level sensor based on mega16m1
[16:40:41] <hjohnson> i'm doign that to get my feet wet on a cheaper project first, make sure my soldering skills are up, and so forth on something that has a bom cost of $40 or so, rather than $500 :o
[16:41:00] <megal0maniac> Ah, for the CAN
[16:41:05] <hjohnson> yeah
[16:41:39] <hjohnson> http://gerblook.org/pcb/HY9q99BEZy8VN7Z5eWvSHj that's my tank level sensor right now
[16:42:16] <hjohnson> so testing my ability to build a) a buck supply b) running QFNs
[16:43:54] <megal0maniac> Nice :)
[16:45:18] <hjohnson> i'll need to bit-bang I2c, but that's not too hard
[16:50:05] <megal0maniac> I feel like it might be easier than using the dedicated peripheral :P
[16:50:55] <hjohnson> heh
[17:10:50] <Tom_itx> hjohnson, you gonna try to hand solder qfn?
[17:11:00] <hjohnson> Tom_itx: no, i'm going to reflow it
[17:11:04] <Tom_itx> if you are, i'd mod the pads so they extend beyond the chip edge
[17:11:19] <Tom_itx> i reflowed a few in my oven with mixed results
[17:11:32] <hjohnson> Tom_itx: part of this is to test and practice my reflow technique
[17:11:46] <hjohnson> since my eventual project is to build this:
http://gerblook.org/pcb/imgmxHk2oBxBy6QPXSVKBB#front
[17:12:02] <Tom_itx> http://tom-itx.no-ip.biz:81/~webpage/boards/atmega32u4/atmega32u4_1.jpg
[17:12:20] <Tom_itx> those did ok but i did have to touch them up a bit with the iron
[17:13:00] <Tom_itx> the header looks like it could be fun
[17:13:17] <Tom_itx> the rest not so bad
[17:13:17] <hjohnson> which header?
[17:13:26] <Tom_itx> at the top
[17:13:31] <Tom_itx> looks like a header anyway
[17:13:31] <hjohnson> J2?
[17:13:36] <Tom_itx> yeah
[17:13:40] <hjohnson> actually that's 0.5mm, not too bad
[17:13:45] <hjohnson> i've done those by hand
[17:13:51] <Tom_itx> same
[17:14:16] <hjohnson> the tough one is the GPS LNA (U19) and the other QFNs
[17:14:45] <hjohnson> i'm pretty happy with Exar though, they sent me $90 in UARTs for free :P
[19:37:10] <hjohnson> hrmm.. trying to remember... on the avr, when an interrupt fires, does it automatically push the entire register file onto the stack, or do you have to take care of the registers yourself?
[19:37:15] <hjohnson> (in an interrupt handler)
[19:37:45] <LoRez> you push what you're going to mess with generally
[19:37:52] <hjohnson> that's what I thought
[19:38:46] <Valen> gcc takes care of it for you if you are using that I believe
[19:39:17] <hjohnson> Valen: yeah, but now that I think about it, I remember it pushing all the registers onto the stack even if I wasn't using them
[19:40:09] <LoRez> ah, in gcc, yeah, it'll do it for you. I figured you were playing with assembly
[19:40:37] <hjohnson> LoRez: well, yeah, i'm debating whether I should hand-code the assembly for this one interrupt handler, or just write it in C and let it optimize as best it can
[19:54:29] <Lambda_Aurigae> write it in C then hand optimize the generated assembly!
[19:54:39] <hjohnson> Lambda_Aurigae: hah
[19:55:06] <Lambda_Aurigae> that way you can cut out a lot of things you don't need like a plethora of register pushes and such.
[19:55:48] <hjohnson> the handler I'm thinking about is basically just to clock in/out data for bit-banging I2C
[21:42:55] <Engen> Anyone here familiar with ALU design?
