Electrical Engineering V3 - Developers

Reminds me of the time I went out to my parent's shed to find something I had stored there, and had discovered the maggots of mud-dauber wasps (deceased) encased in cocoons of clay gathered by the mother wasp all over an older Compaq keyboard of mine. :sick:

Can someone let me know if this will work properly? It should, in theory, toggle OUT between 12v and Gnd with every low-edged pulse of TRIG. (the logic gate is a JK gate that toggles on the rising edge, so I added an inverter) [t]http://w3axl.com/wp-content/uploads/2016/05/sch3.png[/t] I don't do much with logic so this was made after much google-fu.

[QUOTE=papkee;50402347]Can someone let me know if this will work properly? It should, in theory, toggle OUT between 12v and Gnd with every low-edged pulse of TRIG. (the logic gate is a JK gate that toggles on the rising edge, so I added an inverter) [t]http://w3axl.com/wp-content/uploads/2016/05/sch3.png[/t] I don't do much with logic so this was made after much google-fu.[/QUOTE] Remove the input inverter and it'll work. Also an output buffer isn't really needed, CMOS logic has fairly good output drive as it is.

Why no inverter? If I don't include it, my radio won't turn on until I release the power button. From the factory it's supposed to turn on as soon as the button is pressed. Explain the magic please [editline]27th May 2016[/editline] This is replacing a stock power toggle circuit that I'm retrofitting into one that doesn't have it.

[QUOTE=papkee;50402571]Why no inverter? If I don't include it, my radio won't turn on until I release the power button. From the factory it's supposed to turn on as soon as the button is pressed. Explain the magic please [editline]27th May 2016[/editline] This is replacing a stock power toggle circuit that I'm retrofitting into one that doesn't have it.[/QUOTE] Ah I thought you wanted the reverse, keep the inverter then.

I'm looking for someone who's willing to do some minor freelancing work for me for a personal project. Can't pay much sadly (up to 70 eur or so could discuss more). All I need is the circuit diagram really. I need something that can do passthrough audio (input/output RCA plug), Ethernet and has a fast enough CPU and enough ram to sample audio at between 320 and 192 KB/s and store that for up to 30 seconds. Pref something where I don't need to write my own network stack. So if it can run a tiny build of Linux or (net)BSD that would be awesome. I'm only analysing the audio and sending information about that to a server.

Raspberry PI (30€) + USB supported sound card (10€) [url]http://elinux.org/RPi_VerifiedPeripherals#USB_Sound_Cards[/url]

[QUOTE=Fourier;50417778]Raspberry PI (30€) + USB supported sound card (10€) [url]http://elinux.org/RPi_VerifiedPeripherals#USB_Sound_Cards[/url][/QUOTE] I want to make a bunch of them and I want a good excuse to do some hardware programming for once.

A few months ago I got a package with Arduino Nanos in it. I decided to update their firmware because of the storage boost, but unfortunately I may have bricked them. The first two I am pretty sure that I've done the wiring wrong, resulting in both controllers being unresponsive when you're uploading a sketch to it, and the power led is on while the board is powered. The third one I wired it right, and tried to burn the bootloader, but Arduino failed to do it, resulting in the same as above. What I'd like to know is if it is irreversible, and it not, how can I get them working again.

[QUOTE=Mega1mpact;50417855]I want to make a bunch of them and I want a good excuse to do some hardware programming for once.[/QUOTE] well, then you need ARM with good ADC and ethernet module

[QUOTE=Fourier;50421040]well, then you need ARM with good ADC and ethernet module[/QUOTE] Would a SOC be worth looking into?

If you can't pay more than ~70€ for the design, you're definitely not going to use a SoC for it. Shit's expensive.

If you just want it to light up, I don't see why you'd need a microcontroller. A normally open microswitch controlling an NMOS, would work. Power -> resistor -> microswitch -> NMOS gate. NMOS gate -> resistor -> ground (pull gate low when microswitch isn't passing voltage through to the gate). Power -> LED strip -> NMOS drain.

If thought you really want a micro controller, go for the attiny85, its a 8 pin chip, if you have an arduino you can program it with that

LDR + op amp.

Reed switch, magnet pellet, LED strip and a power source. This doesn't even require a transistor. [editline]30th May 2016[/editline] [QUOTE=Satane;50421796]I also want to make it not turn on if the room is bright enough.[/QUOTE] Fuck, there goes my idea. :v:

[QUOTE=Satane;50421413]What should I get if I wanna make some drawers light up when I open them ? I'm guessing a bit of led strip, some kind of switch and some arduino thing. What type of switch would work best? What would be the cheapest microcontroller I can just plug in and use with like 10-15 io ports?[/QUOTE] [t]http://i.imgur.com/CkpSQFi.png[/t] That only has a single LED but that might do the job if you use a high brightness one, the off current is small enough that you could power it for a very long time with a small li-ion battery, even a coin cell would work if you don't open the draw very often.

[QUOTE=Satane;50423119] Something like this? [url]http://www.ebay.com/itm/5PC-Recessed-Magnetic-Window-Door-Contact-Security-Safety-Alarm-Switch-Reed-/141916704436?hash=item210ae50eb4:g:50EAAOSwKIpWAQem[/url][/QUOTE] That was the idea.

[QUOTE=Mega1mpact;50421189]Would a SOC be worth looking into?[/QUOTE] Why? You want to make 10 units, not 10000. but if you mean domain specific chip just for this purpose, maybe, but it will also wont cheap

[QUOTE=Mega1mpact;50417855]I want to make a bunch of them and I want a good excuse to do some hardware programming for once.[/QUOTE] The RPi also has a I2S interface on the GPIO header, so you could pair one with a decent codec and have a slightly nicer solution. If you wanted to build the entire board then the higher end Cortex-M parts start getting things like ethernet PHYs, DACs and larger memories, but they will still only run an RTOS and not Linux. STMicro make a huge range of MCUs so it's probably worth checking out. For SoCs you'd probably be limited to TI or Freescale, in actually being able to buy them, but as mentioned, it quickly gets expensive. Freescale do have some in large QFP parts last I checked but you'd need the SoC, RAM, flash, and make sure that you're routing was good enough, probably on a 4 layer board... You can get COMs (computer on modules) but they generally don't start cheap, you could possibly use the RPi Zero in the same way, solder the boards together through the GPIO header to get I2S and power, you would want to use the USB OTG for an ethernet adapter though, which could be on your board if you can get an ethernet part. You can use parts like the ENC28J60 over the GPIO header but that's not fast, < 10Mbit/s.

Started working on a robot, got done with the basic layout for now. [t]https://dl.dropboxusercontent.com/u/43645231/photos/electro/robot/2016-05-30 21.54.04.jpg[/t] I first want to get it working with user input (sending controller commands via RF), after that I'll look at using some sensors like the already mounted ultrasonic distance sensor at the front. After that, I might go look at more advanced stuff involving a raspberry pi.

[QUOTE=ben1066;50423888]The RPi also has a I2S interface on the GPIO header, so you could pair one with a decent codec and have a slightly nicer solution. If you wanted to build the entire board then the higher end Cortex-M parts start getting things like ethernet PHYs, DACs and larger memories, but they will still only run an RTOS and not Linux. STMicro make a huge range of MCUs so it's probably worth checking out. For SoCs you'd probably be limited to TI or Freescale, in actually being able to buy them, but as mentioned, it quickly gets expensive. Freescale do have some in large QFP parts last I checked but you'd need the SoC, RAM, flash, and make sure that you're routing was good enough, probably on a 4 layer board... You can get COMs (computer on modules) but they generally don't start cheap, you could possibly use the RPi Zero in the same way, solder the boards together through the GPIO header to get I2S and power, you would want to use the USB OTG for an ethernet adapter though, which could be on your board if you can get an ethernet part. You can use parts like the ENC28J60 over the GPIO header but that's not fast, < 10Mbit/s.[/QUOTE] Microchip has the PIC32MZ series which comes in a reasonable package and enough onboard RAM to pull it off, but yeah, you're gonna hit 70 EUR just in parts pretty fast.

Perfect timing with upgrading to gold. GENTLEMEN. I present some custom avionics which are still to be expanded for future versions for model rocketry! Overview video of the electronics: [video=youtube;eGEEWhy_IT8]http://www.youtube.com/watch?v=eGEEWhy_IT8[/video] Here's the results of my [URL="https://sites.google.com/site/lonewolfscircuits/sitefiles/Lunar_Express_Mk1_Flight_1_Data_Summary.PNG?attredirects=0"]two[/URL] [URL="https://sites.google.com/site/lonewolfscircuits/sitefiles/Lunar_Express_Mk1_Flight_2_Data_Summary.PNG?attredirects=0"]flights[/URL] recorded by the avionics (and [URL="https://sites.google.com/site/lonewolfscircuits/sitefiles/5-28-2016_4-28-pm_avionics_log_final.xls?attredirects=0&d=1"]one of the raw data logs straight from the terminal & processed[/URL]), as well as their [URL="https://sites.google.com/site/lonewolfscircuits/sitefiles/B6-4_Launch_Simulation_Results.png?attredirects=0"]counterpart[/URL] [URL="https://sites.google.com/site/lonewolfscircuits/sitefiles/C6-5_Launch_Simulation_Results.png?attredirects=0"]simulations[/URL] (and [URL="https://sites.google.com/site/lonewolfscircuits/sitefiles/Parachute_Descent_Simulation_Results.PNG?attredirects=0"]descent rate[/URL]). Fairly close in apogees. Here is the [URL="https://sites.google.com/site/lonewolfscircuits/sitefiles/Avionics_Overview.png?attredirects=0"]block diagram of the entire system[/URL], the [URL="https://sites.google.com/site/lonewolfscircuits/sitefiles/Lunar_Express_Mk1_Parts_List.xls?attredirects=0&d=1"]parts/mass list of both the rocket and avionics[/URL], the code is still in beta and a proper schematic is in the works. ALSO there was this [URL="https://scontent.xx.fbcdn.net/v/t1.0-0/q87/p206x206/13332928_10209596503259096_8959009184298670642_n.jpg?oh=4878f4ee0be660513d3bcaff0756c69e&oe=57DE7DA0"]massive as fuck rocket[/URL] (38lbs/17.2kg total with an apogee of 6000'/1828m) at the launch event I went to.

I didn't think this through [t]https://dl.dropboxusercontent.com/u/43645231/photos/electro/2016-06-01 16.16.54.jpg[/t] One of the caps basically touches the heatsink. I wonder how fast the capacitors will get fucked up by the heat they're gonna be receiving :v: I guess I'll turn around the heatsink, tho that'll ruins the ~aesthetic~

[QUOTE=scratch (nl);50436264]I didn't think this through [t]https://dl.dropboxusercontent.com/u/43645231/photos/electro/2016-06-01 16.16.54.jpg[/t] One of the caps basically touches the heatsink. I wonder how fast the capacitors will get fucked up by the heat they're gonna be receiving :v: I guess I'll turn around the heatsink, tho that'll ruins the ~aesthetic~[/QUOTE] Only depends upon how much power will be dissipated, and [URL="https://en.wikipedia.org/wiki/Electrolytic_capacitor#Comparison_of_electrolytic_capacitor_types"]aluminum electrolytics are pretty robust[/URL]. (Assuming extreme circumstances) By the time they're close to failing, the thermal shutdown of the 7805CV would kick in well before, as the junction temperature of it would be like +20°C of the tip of the heatsink.

[QUOTE=LoneWolf_Recon;50436439]Only depends upon how much power will be dissipated, and [URL="https://en.wikipedia.org/wiki/Electrolytic_capacitor#Comparison_of_electrolytic_capacitor_types"]aluminum electrolytics are pretty robust[/URL]. (Assuming extreme circumstances) By the time they're close to failing, the thermal shutdown of the 7805CV would kick in well before, as the junction temperature of it would be like +20°C of the tip of the heatsink.[/QUOTE] However, continously high temperatures significantly shorten the life of capacitors.

When that happens to me I either bend the fin another direction or just snap it off.

Are those universal memory programmers on ebay good? I've got some TSOP flash chips that need to be programmed and I was thinking about getting one of those and a tsop adapter. I figure I'll have other uses for the programmer as well so I can justify $50.

I've been running a Willem programmer for at least two years now. I can tell you that out of the box it really can't do any chips out of the ordinary but for conventional EEPROMs and EPROMs plus BIOS flash chips it isn't too bad. Supposedly the newer chinese USB units though can handle much newer chips.

Figured I would ask here. Have any of you built something and thought it was nice enough to revision so you don't electrocute yourself anymore? I want to cover my lighting project with a plastic mold but I don't know where or how to do that. A friend noticed it and asked if my time machine exploded...