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JawnV6 posted:im not sure how to set your problem up, but i'd imagine it's measuring degrees off the vertical. "if i'm over 2 degrees the wrong way, fire the solenoid" is the problem statement? forget about time for now, how precise do you need the degree measurement to be? p much yeah, and i have no idea  i'm just copying that paper mostly. once i have anything working, in about 10 years, i'll look to lower the price.
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Feb 18, 2017 08:24
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https://www.arduino.cc/en/Tutorial/Potentiometer why this tutorial say to connect 1 pin with ground, one with the board, and then 1 to +V? surely the same effect is achieved with enabling the internal pullup resistor, then connecting it to the middle pin then connecting ground to either of the side ones?
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Feb 19, 2017 15:33
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if you connect both ends of the potentiometer to ground then the mid point will always be ground regardless of where you turn it.
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Feb 19, 2017 15:45
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Sweevo posted:if you connect both ends of the potentiometer to ground then the mid point will always be ground regardless of where you turn it. i get that, what i'm asking is the diff between code:code:
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Feb 19, 2017 16:26
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the goal is to use the pot as a voltage divider presumably. if you just pull up the middle of the pot you have... something. not a voltage divider. well at least not a useful voltage divider
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Feb 19, 2017 17:03
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Bloody posted:the goal is to use the pot as a voltage divider presumably. if you just pull up the middle of the pot you have... something. not a voltage divider. well at least not a useful voltage divider i see, it goes between 0 and 5 with all three pins connected. with just the middle you have something that goes between x and y where 0 < x < y < 5 and they both depend on the exact resistors involved
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Feb 19, 2017 17:08
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assuming you can enable the adc input and the pull up resistor at the same time then yeah
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Feb 19, 2017 17:21
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gonadic io posted:i see, it goes between 0 and 5 with all three pins connected. well, it'd go 0 < y < 5 tbh. the circuit pre: v0
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if you connect the potentiometer like the datasheet says, it's a slightly different situation because r1+r2 = some constant resistance always, so you can actually get all the way up to 5V as well as down to 0. also like bloody says you may not be able to enable that pullup and the adc at the same time.
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Feb 19, 2017 17:47
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the 0 x y 5 case was the hypothetical one with the pull up n poo poo
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Feb 19, 2017 17:48
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Bloody posted:the 0 x y 5 case was the hypothetical one with the pull up n poo poo More like 4 x y 20 lmao
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Feb 20, 2017 00:11
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gonadic io posted:
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Feb 20, 2017 02:09
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I think hardware RE seems really cool--that 33c3 talk on hacking pay-tv authorization / encryption was eye opening as an end-to-end display of ability. Are there any starter things for hardware hacking like there is CTF for software? Trying to think of some fun stuff to plug a JTAG or logic analyzer into that would be a good noob project.
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Feb 20, 2017 03:19
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Hed posted:I think hardware RE seems really cool--that 33c3 talk on hacking pay-tv authorization / encryption was eye opening as an end-to-end display of ability. Are there any starter things for hardware hacking like there is CTF for software? Trying to think of some fun stuff to plug a JTAG or logic analyzer into that would be a good noob project. the bunnie book about the xbox is cool. it goes over some beginner stuff and also some stuff like tapping into the HT bus but it's also an interesting read regardless of your expertise, sort of like watching any of the youtube hardware channels. you can get it for free too http://bunniefoo.com/nostarch/HackingTheXbox_Free.pdf edit: sorry, i actually read your post - dump cartridge video games - routers - convert a oldass keyboard to usb with like a teensy hifi fucked around with this message at 03:30 on Feb 20, 2017 |
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Feb 20, 2017 03:25
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so cool. i used to handle LN-200 IMUs while working at an aviation company but never saw an open one.
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Feb 20, 2017 18:08
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Hed posted:I think hardware RE seems really cool--that 33c3 talk on hacking pay-tv authorization / encryption was eye opening as an end-to-end display of ability. Are there any starter things for hardware hacking like there is CTF for software? Trying to think of some fun stuff to plug a JTAG or logic analyzer into that would be a good noob project. Theres a company here in the Netherlands called Riscure thats one of the leading ones in the field afaik and they do a ctf every year where they mail you a I had the opportunity to play with some of their equipment last week, voltagr glitching a smarcard, and it owns major bones. e: http://rhme.riscure.com/home spankmeister fucked around with this message at 18:17 on Feb 20, 2017 |
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Feb 20, 2017 18:15
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Thanks for the book link and the ideas guys. I will definitely check out the next CTF from that place. Wanna get that green glitcher 
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Feb 21, 2017 03:13
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Bah, still having issues with Rust and my Arduino. Anybody want to weigh in? http://stackoverflow.com/questions/42368675/why-does-getting-the-address-of-certain-linker-variables-halt-samd21-execution-i Honestly at this point I'm not far off just creating a dynamic library in Rust and doing the setup in C to call the Rust library.
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Feb 21, 2017 15:31
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at some point you'll have to read asm. if you've minimized it down to that one line, figure out what assembly is being generated from it one of the common tricks is to use a "b .", in C i'd write: __asm("b .") with volatility or memory clobber if the compiler was getting too clever with it. that opcode says "jump to the beginning of this instruction" so when the processor hits it, it'll spin right there until you interrupt with the debugger. from there you can manually adjust the PC and step over the instruction to see when the fault happens. put one right before your attempt to grab the etext my guess, based on kinda scanning the SO, is that rust isn't letting you see/touch that pointer and is subbing in some garbage value like 0x0 that's causing a DATA ABORT
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Feb 21, 2017 19:47
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what is a good ide to use with STM32 mcus? arduino due is a very comfortable environment but i can't ignore how ridiculously cheap the stm32f103c8 is so i ordered some eval boards and a cheap programmer in case the UART bootloader doesn't work
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Feb 21, 2017 19:57
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avoid The CUBE at all costs vim/emacs would be better
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Feb 21, 2017 20:16
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longview posted:what is a good ide to use with STM32 mcus? eclipse is ok, there's ARM gcc and openocd plugins that work as well as any other embedded tool chain (that is to say, finicky) http://gnuarmeclipse.github.io by eval board did you mean a nucleo board? if thats the case use the mbed online compiler until you hate it enough to spend an afternoon setting up toolchains
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Feb 21, 2017 20:23
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hobbesmaster posted:eclipse is ok, there's ARM gcc and openocd plugins that work as well as any other embedded tool chain (that is to say, finicky) http://gnuarmeclipse.github.io Yeah the eclipse/GCC toolchain is pretty great. Also grab the drivers from the STMCube, they seem to work just fine
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Feb 21, 2017 20:28
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Alright, I'll give Eclipse + extensions a try, thanks guys. though i might also see if the stm32 arduino port works at all, mostly depends on how much work it is to set up a graphics library with the normal ARM libraries. for my eval board i just ordered some of these: https://www.aliexpress.com/item/STM32F103C8T6-ARM-STM32-Minimum-System-Development-Board-Module-For-Arduino/32279776568.html really basic stuff that i should be able to put on a bread board to get the feel for the platform. i'm planning on rolling my own board initially to convert some old panasonic car-phones into 430 MHz ham radios, i need to drive an OLED display and maybe do a bit of tone generation with PWM so not doing anything really special. if it wasn't for the OLED display i could probably fit most of the functionality in an atmega328 or two. but if i can get it running without too many tears i'll probably use the chip for lots of other things since it's so nice to have enough ram to buffer at least an entire 128x64 mono display + be able to use floating point where needed without taking several ms per calculation
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Feb 21, 2017 20:49
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i want to reverse engineer one specific thing I have an old Japanese maritime weatherfax receiver that uses metallized recording paper and an electric stylus to print out wefaxes, but the "zones" and "stations" and "channels" are all hardcoded. I opened it up hoping for potentiometers or something and found it's stuffed full of dozens of ICs and either one or two ROMs (IIRC) plus all the analog parts no idea what even architecture it is
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Feb 21, 2017 21:17
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google the part numbers on the silkscreens a lot of it might also be something from this list: https://en.wikipedia.org/wiki/List_of_7400_series_integrated_circuits
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Feb 21, 2017 21:26
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some old designs used ROMs as gate arrays/lookup tables so if all you find is ROMs + standard logic that might be what they're doing
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Feb 21, 2017 21:46
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longview posted:some old designs used ROMs as gate arrays/lookup tables so if all you find is ROMs + standard logic that might be what they're doing if that's the case i'm even more hosed than if I had to disassemble some antique 4004 code or something and find integers i hate digital poo poo
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Feb 21, 2017 22:01
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hmm, this doesn't look goodcode:
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Feb 22, 2017 00:50
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I told you, bro! I told you about microprocessors! I warned you, dawg!
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Feb 22, 2017 01:48
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JawnV6 posted:avoid The CUBE at all costs
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Feb 22, 2017 06:23
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dumb noob question if i only have a 24V battery, and i use some DC/DC regulator to get it to 3.3 can i have pre:+24V ----- motor --|
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+0v --------------|i.e. i don't need to protect the arduino from the ground rail, 0 is 0? the motor will have a rectifier diode to prevent kickback.
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Feb 22, 2017 18:23
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i mean i'll probably have to step up to 24 instead of stepping down to 3.3 but the question is still relevant
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Feb 22, 2017 18:25
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triple post project update: i got digitial pio working in rust so my single-digit-button-counter https://www.youtube.com/watch?v=S8MtqhWVQ2E&hd=1 is now implemented entirely in rust with a little bash script to compile and upload! it's not especially good code, and i still can't get the address of __etext, but i'm pretty pleased that it's working
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Feb 22, 2017 21:46
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gonadic io posted:dumb noob question 0 is 0, yeah. some people might still warn you about noise from the motor, idk. do you want to control the motor using the arduino? i used https://www.sparkfun.com/products/10213 to control a higher voltage DC motor from a 3.3V arduino.
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Feb 22, 2017 21:52
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yippee cahier posted:0 is 0, yeah. some people might still warn you about noise from the motor, idk. yeah i have a bunch of those, currently i'm blinking an led with one but the plan is to control motors/solenoid valves with them
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Feb 22, 2017 21:54
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Yeah zero is zero mostly although the motor may make your ground noisy n poo poo
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Feb 22, 2017 22:07
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ie "ground is ground unless it isn't and then you're hosed"
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Feb 22, 2017 22:15
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nah like if you're working with highly sensitive analog stuff then you probably need to take caution with your grounds because they're not all zero and it matters n poo poo
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Feb 23, 2017 04:12
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it's all fun and games until your inductive load starts ringin', flips that pulse around, and rams it backwards through your switching bank and capacitor
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Feb 23, 2017 12:11
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atomicthumbs posted:it's all fun and games until your inductive load starts ringin', flips that pulse around, and rams it backwards through your switching bank and capacitor got myself some rectifier diodes to put across the motors and solenoid valves
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Feb 23, 2017 12:54
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