Electrical Engineering V3 - Developers

Anyone got experience with developing for STM32 or ARM MCUs in general? I'm looking to make a development board as a project (currently at a very general block diagram stage, nothing concrete as of yet except I'm probably going to be using an STM32F091), and I'm having trouble figuring out what my toolchain/programmer should be. The only MCU I've got any real experience with is PIC with MPLAB/PicKit 3. Ideally I'd like something with similar debugging capabilities within a reasonable budget. Should I go for a JTAG programmer, or ISP (which seems to be cheaper)? Any recommendations on development environment?

[QUOTE=LoneWolf_Recon;48889971]Hey guys, I'm having some trouble with my buck converter. Needless to say the output voltage is dropping from my designed 8V (Which holds steady to about 300mA Load) to around 6.5V at +500mA. I've verified that the MOSFET is being driven fully into saturation and all my other specs are correct, however I think I designed the inductor too high at 33uH thus having a slow inductor current response time to power the load at the right voltage.[/QUOTE] Increase R1 to 20m. [QUOTE=Nevec;48891599]Does anyone have any experience with EEGs for Arduino (or other platforms)? I want to make a simple sleep analyzer. Is it hard to make my own EEG? Or are there any cheap, ready-made kits?[/QUOTE] You can get ICs specifically designed for such an application, it's also possible to make your own using instrumentation amplifiers but it's not particularly easy, no idea about kits.

[QUOTE=DrDevil;48890495]Why no isolation slots?[/QUOTE] Can't see the voltage going high enough to -really- need it. all the low voltage will be isolated too. I might think about adding some on the next revision anyway.

[QUOTE=Dolton;48890046][URL="http://cds.linear.com/docs/en/datasheet/1624f.pdf"]The datasheet[/URL] has a couple equations for inductor selection but generally, no reducing the size will not help. The size of the inductor has more to do with ripple rejection, and mode of operation (CCM vs DCM). Do you have an oscilloscope to see what is happening at each node when the output voltage drops?[/QUOTE] I have a feeling it's somehow still in burst mode operation based upon the TG pin's trace. ([URL="https://sites.google.com/site/lonewolfscircuits/sitefiles/Traces.zip?attredirects=0&d=1"]Zip File of all traces[/URL]). That was an oversight on my part with R1, and I've set that to 20mOhms now. As far as I can tell the MOSFET is driving just fine as well as the diode, but something with the feedback to the LTC1624 seems to be the problem if (I think) its still stuck in burst mode while under heavy load.

So all but one set of the LEDs I ordered from China last week have arrived and I wanted to test them all out to make sure they're working because some have black specks in the center of the diode, or semiconductor part seems off center. But anyway, I went looking for my resistor collection so I could test them on a 9v battery. I couldn't find them anywhere. I don't know whats up with that. Walked outside on the porch to rummage through some junk I found [url=http://anotherprophecy.com/files/12vps.jpg]this[/url]. I think the ghost that haunts this house is fucking with me, then felt bad and brought me a power supply.

Probably verify that supply isn't an IED before you start using it though. Sketchy ungrounded plug and everything.

[t]https://i.imgur.com/ovdyR3F.jpg[/t] 800MHz folded dipole array is up. Now to get Unitracker and DSD+ running so I can listen to some police/EMS/business chatter. Also my [url=http://www.marinetraffic.com/en/ais/details/stations/2852]AIS station[/url] went up over the previous weekend; same concept, but in the VHF band instead of UHF band. [t]https://i.imgur.com/uoGs8ht.jpg[/t]

[QUOTE=papkee;48902978]Probably verify that supply isn't an IED before you start using it though. Sketchy ungrounded plug and everything.[/QUOTE] When I found it earlier, I powered it on. It hummed quietly, but with noticeable sound.

[QUOTE=false prophet;48903112]When I found it earlier, I powered it on. It hummed quietly, but with noticeable sound.[/QUOTE] Probably fine then, it looks like an old linear supply, I would however pop the case off and look at the input to the transformer to make sure there is no damage to the cable. Preferably the case should be earthed with a 3 pin plug, however it isn't a big deal with a linear supply as long as the primary side wiring is in good condition. One thing you can do to increase safety is fit a polarized plug and connect the case to neutral, this might not be desired however if you want a totally isolated output.

Well, my soldering iron and the needle on it has oxidized completely. Time to buy a new one that isn't piece of crap. Been looking at this one all day: [url]http://www.amazon.com/dp/B000AS28UC/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&colid=2OV5Y7YAY51LF&coliid=I8HS1J97R422H[/url] Yay or Nay?

[QUOTE=false prophet;48903344]Well, my soldering iron and the needle on it has oxidized completely. Time to buy a new one that isn't piece of crap. Been looking at this one all day: [url]http://www.amazon.com/dp/B000AS28UC/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&colid=2OV5Y7YAY51LF&coliid=I8HS1J97R422H[/url] Yay or Nay?[/QUOTE] It's not bad but you might want a little more power. For example [url]http://www.ebay.com/itm/ATTEN-937b-Anti-static-AC-110V-50W-Rework-Soldering-Station-Iron-Lead-Free-/160920947570?hash=item2577a2cb72[/url] or for a little more [url]http://www.ebay.com/itm/ATTEN-Digital-SOLDERING-STATION-AT201D-60W-Anti-Static-Lead-Free-UL-Listed-/150704523692?hash=item2316b089ac[/url] The tips and heating element are extremely cheap (but good) for those as well.

I just want temperature control. My current iron just heats up as much as it can, to the point that it becomes unusable due to burning my hand and not tinning.

For a home use iron, temperature control and Hakko 900-tip compatibility would pretty much be what I'd require. Being able to use the Hakko tips is nice, since apparently half of mainland China is building fake ones, so you can get them for cheap on eBay.

I recently got an 888D and love it to death. It's a huge upgrade from my pencil iron with the sanded tip that barely works.

Do not sand tips, you'll just fuck up the coating and now you've got the metal of the tip bonding with the tin, so it gets chewed up real fast.

[QUOTE=nikomo;48905803]Do not sand tips, you'll just fuck up the coating and now you've got the metal of the tip bonding with the tin, so it gets chewed up real fast.[/QUOTE] Oh I'm well aware. It was literally a case of "okay, we really need to get this done and the tip's fucked"

[QUOTE=false prophet;48903344]Well, my soldering iron and the needle on it has oxidized completely. Time to buy a new one that isn't piece of crap. Been looking at this one all day: [url]http://www.amazon.com/dp/B000AS28UC/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&colid=2OV5Y7YAY51LF&coliid=I8HS1J97R422H[/url] Yay or Nay?[/QUOTE] It's amazing in how many brands and shapes this iron comes in, I've probably seen over 10 different brands of the exact same iron so far. It's an ok iron, but it takes forever to get to temperature. I wouldn't pay more than 20$ including shipping for it though.

[QUOTE=false prophet;48903344]Well, my soldering iron and the needle on it has oxidized completely. Time to buy a new one that isn't piece of crap. Been looking at this one all day: [url]http://www.amazon.com/dp/B000AS28UC/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&colid=2OV5Y7YAY51LF&coliid=I8HS1J97R422H[/url] Yay or Nay?[/QUOTE] I'd recommend you to do some searching on red Weller products, there are some very strong opinions on them out there. If I remember correctly there isn't really any type of temperature feedback in that Weller iron either, the controller is just something comparable to a dimmer. Also, got something in for adjustment. [url=http://i.imgur.com/Ff3OaWc.jpg][img]http://i.imgur.com/Ff3OaWcl.jpg[/img][/url]

[QUOTE=ddrl46;48908758]I'd recommend you to do some searching on red Weller products, there are some very strong opinions on them out there. If I remember correctly there isn't really any type of temperature feedback in that Weller iron either, the controller is just something comparable to a dimmer. Also, got something in for adjustment. [url=http://i.imgur.com/Ff3OaWc.jpg][img]http://i.imgur.com/Ff3OaWcl.jpg[/img][/url][/QUOTE] Holy hell is that your lab?

there's so many buttons can i touch them

So I've got an SSOP chip with some solder bridges [I]under[/I] the pins, like behind them between the pads and the chip itself. I can't get them to wick away at all, even when I add more solder and wick then. They're pretty much stuck there. Any ideas?

Desolder chip and then resolder it, properly.

[QUOTE=papkee;48917473]So I've got an SSOP chip with some solder bridges [I]under[/I] the pins, like behind them between the pads and the chip itself. I can't get them to wick away at all, even when I add more solder and wick then. They're pretty much stuck there. Any ideas?[/QUOTE] Pics? Use more flux.

[QUOTE=nikomo;48917532]Desolder chip and then resolder it, properly.[/QUOTE] Yeah, I'll probably just end up doing that the next time I get access to a hot air station. It'll be the second time I've had to desolder this thing; the first was because of bad placement. It's all a learning experience, right?

got a 90W hair removal laser from garage sale for 10 bucks. a small wire made it not work, this was fixed quickly. now im burning some things and sell it then, because its listed on the internet for 38000€ / 55000$ [t]http://fs5.directupload.net/images/151018/cinitudh.jpg[/t] [t]http://fs5.directupload.net/images/151018/9i93smn8.jpg[/t] burning stuff is fun: [video=youtube;A-6_xjOqMWs]http://www.youtube.com/watch?v=A-6_xjOqMWs[/video]

Would mounting many smaller boards to a larger metal plate work as an efficient common ground, or would I run into issues with ground loops, etc? I want to use a large metal enclosure, but if I were to make one pcb to fit the card guides I'd be looking at $100. I'd rather slide the metal plate into the card guides and mount the smaller boards onto it.

[QUOTE=papkee;48932665]Would mounting many smaller boards to a larger metal plate work as an efficient common ground, or would I run into issues with ground loops, etc? I want to use a large metal enclosure, but if I were to make one pcb to fit the card guides I'd be looking at $100. I'd rather slide the metal plate into the card guides and mount the smaller boards onto it.[/QUOTE] How many boards and what do they do? I'm about to pick up this receiver that has some issues with the left channel. When I looked up the model on google I came across this [URL="https://docs.sony.com/release/ES_STR_05_Final.pdf"]technical brochure from Sony[/URL]. There's some great reading in it such as: [img]http://i.imgur.com/48CPUYk.jpg[/img] [img]http://i.imgur.com/K5OUINL.jpg[/img] [img]http://i.imgur.com/psI3Vvw.jpg[/img] :hammered:

[QUOTE=No_Excuses;48950006]How many boards and what do they do? I'm about to pick up this receiver that has some issues with the left channel. When I looked up the model on google I came across this [URL="https://docs.sony.com/release/ES_STR_05_Final.pdf"]technical brochure from Sony[/URL]. There's some great reading in it such as: [img]http://i.imgur.com/48CPUYk.jpg[/img] [img]http://i.imgur.com/K5OUINL.jpg[/img] [img]http://i.imgur.com/psI3Vvw.jpg[/img] :hammered:[/QUOTE] its easy to sell this shit to audiophiles nowadays you just need to call anything analog to get it to sell

[QUOTE=No_Excuses;48950006]How many boards and what do they do? I'm about to pick up this receiver that has some issues with the left channel. When I looked up the model on google I came across this [URL="https://docs.sony.com/release/ES_STR_05_Final.pdf"]technical brochure from Sony[/URL]. There's some great reading in it such as: :hammered:[/QUOTE] This is so dumb, everyone knows you can do the same thing by putting [URL="http://www.coconut-audio.com/proximitystone.html"]sparkly rocks[/URL] on top of the equipment. You won't even notice the improvement unless your power cables are [URL="http://www.coconut-audio.com/straightpower.html"]wrapped in carpet[/URL] and you turn every light off for an hour before hand to let the resonating power fluctuations dissipate.

[QUOTE=helifreak;48950330]This is so dumb, everyone knows you can do the same thing by putting [URL="http://www.coconut-audio.com/proximitystone.html"]sparkly rocks[/URL] on top of the equipment. You won't even notice the improvement unless your power cables are [URL="http://www.coconut-audio.com/straightpower.html"]wrapped in carpet[/URL] and you turn every light off for an hour before hand to let the resonating power fluctuations dissipate.[/QUOTE] $30k for that power cable...is that site actually serious? I've seen things like this before but the site layout is so amateur and the name, Coconut Audio.