hybridfree/eevblog-posts huggingface dataset:
STM32F1XX use with Eclipse, Code Sourcery, GNU - Page 1
Forum section: electronics / general

author: Ribster
author_rank: Frequent Contributor
timestamp: November 10, 2013, 11:01:52 pm
content: Hey Everybody,I am putting my toe into the pool of ARM-chips.To cut right to the problem:I'm trying to program an STM32F100C8T6-chip via JTAG.In order to make my .HEX file, i decided to follow the instructions for using Eclipse as an IDE.Ref:https://sites.google.com/site/stm32discovery/open-source-development-with-the-stm32-discovery/setting-up-eclipse-for-stm32-discovery-developmentThere are many tutorials about using this IDE, but this one is pretty detailed.I got it to a point where i have everything to compile, but the linker gives errors.It's about the "stm32_flash.ld" linker file.During my build i get following error:Code:c:/program files (x86)/gnu tools arm embedded/4.7 2013q3/bin/../lib/gcc/arm-none-eabi/4.7.4/../../../../arm-none-eabi/bin/ld.exe:E:/Dropbox/Projecten/_Technisch/Eclipse/A0025 - SE - STM32 breakout\startup_src\stm32_flash.ld:79: syntax errorcollect2.exe: error: ld returned 1 exit statusThe linker flags, and script i am using are the same as the tutorial.Code:-T "${ProjDirPath}\startup_src\stm32_flash.ld" -mthumb -mcpu=cortex-m3 -mfix-cortex-m3-ldrd -Wl,-Map=linker.map -Wl,-cref -Wl,--gc-sectionsThe file has 79 lines, so it doesn't specify at which specific point it is getting into trouble, it just gives an error at the end of the file.Can anyone give me some advice where to look ?I've read somewhere that the linker complaines when something is declared but not defined.Maybe i am including a wrong .c-file, but i have no direction to search with this general error.I already spend 2 weeks into getting this working , so i'm quite desperate.. ;-)Cheers.

author: dannyf
author_rank: Super Contributor
timestamp: November 10, 2013, 11:18:20 pm
content: QuoteCheck out CoIDE: based on eclipse, with the best project wizard in my view.

author: Ribster
author_rank: Frequent Contributor
timestamp: November 10, 2013, 11:22:35 pm
content: Hey Dannyf,Thanks for the fast reply.I've come across CoIDE aswell, but decided to use eclipse. I'll give that one a go.When you say 'Project wizard', do you mean: Easy to follow wizard who does all the setting up for you?Greets

author: dannyf
author_rank: Super Contributor
timestamp: November 10, 2013, 11:30:18 pm
content: QuoteCoIDE IS eclipse, a customized one.Project wizard helps you set up the project and gets you going quickly, which seems to be what your issues are at this point.CoIDE is one of the easiest ARM IDEs I have used, if not the easiest one.

author: Ribster
author_rank: Frequent Contributor
timestamp: November 11, 2013, 12:00:51 am
content: Quote from: dannyf on November 10, 2013, 11:30:18 pmThis is what i'm talking about.15 minutes and the LED's on my self-etched board are blinking.Thanks man, i owe you one!I guess the topic is closed.Will be continued.. With a projectpost.. ;-)

author: dannyf
author_rank: Super Contributor
timestamp: November 11, 2013, 01:49:31 am
content: Glad that it worked for you.
ARM Techcon 2013 - Where's NXP - Page 1
Forum section: electronics / general

author: Pat Pending
author_rank: Regular Contributor
timestamp: November 01, 2013, 06:09:49 pm
content: At ARM Tecthcon the big news was that Intel is now going to fab ARM processorson the other hand NXP was absent from this years event.In prior years NXP had a large presence at the show but not so this past week.What's up with NXP???

author: tszaboo
author_rank: Super Contributor
timestamp: November 07, 2013, 06:48:05 pm
content: Today I walked by their local R&D center, they were still there...
zilog z0860008psc - Page 1
Forum section: electronics / general

author: deames
author_rank: Newbie
timestamp: November 04, 2013, 02:59:03 pm
content: I have a zilog z0860008psc chip. Anyone know what it is and happen to have a pinout for it ?

author: Crazy Ape
author_rank: Regular Contributor
timestamp: November 04, 2013, 08:16:16 pm
content: Read the line after that number, the one that says "Z80 CPU", it should give you a clue as to what it is.The 8 at the end of the number you posted designates speed (8MHz)Info:www.happytrees.org/chips?page=chip&manufacturer=Zilog&part=Z0840008PSChttp://www.cpu-world.com/CPUs/Z80/Zilog-Z0840008PSC.htmlhttp://www.cpu-world.com/info/Pinouts/Z80.htmlIgnore all that, I missed the 6, it's a Z8 CPU.

author: amyk
author_rank: Super Contributor
timestamp: November 05, 2013, 09:10:02 am
content: The Z084is a lot more common... what's the datecode on this one?

author: Crazy Ape
author_rank: Regular Contributor
timestamp: November 05, 2013, 10:05:02 am
content: Quote from: amyk on November 05, 2013, 09:10:02 amYeah, I missed the 6 in the part number, it's a Z8 CPU, not a Z80... OOoops!

author: deames
author_rank: Newbie
timestamp: November 05, 2013, 12:23:31 pm
content: Two other sets of numbers on chip. 73979-1 and 9237. Most definitely not a z80, way too small, only 28 pins.Had a feeling it might be a z8, but can't find any info on it anywhere.

author: Crazy Ape
author_rank: Regular Contributor
timestamp: November 06, 2013, 02:31:05 am
content: Not much info on the net about it (but now it's all in one place)Here's some brief specifications:http://www.datasheetarchive.com/shortform-datasheet/Z08600-08PEC.htmlIt seems it was also known as the "Z8 MP/3/7088 MODEL 7000 R255"http://pdf.datasheetarchive.com/indexerfiles/Datasheets-XX1/DSAXX0078.pdfhttp://cpufpu.ic.cz/zilog/z8.htmlThe 2K ROM makes it pretty much useless as far as reprogramming goes.Pinout (Reconstructed from Kicad file)https://github.com/GaroaHC/PenseBem/blob/master/kicad/lib/z0860008psc.libPin Function--------------------1 +5V2 XTAL23 XTAL14 /RESET5 /DS6 Port3.57 GND8 Port0.09 Port0.110 Port0.211 Port0.312 Port0.413 Port0.514 Port1.015 Port1.116 Port1.217 Port1.318 Port1.419 Port1.520 Port1.621 Port1.722 Port2.123 Port2.224 Port2.325 Port2.426 Port2.527 Port3.128 Port3.6

author: deames
author_rank: Newbie
timestamp: November 06, 2013, 05:35:57 am
content: Thanks Crazy Ape, now I can toss it with a clear conscience. Hate to throw away usable parts.

author: amyk
author_rank: Super Contributor
timestamp: November 06, 2013, 11:20:39 am
content: Unlike the mask-ROM 8051s which could still be used with external ROM by disabling the internal one.
Microchip PIC18 Explorer Board - Page 1
Forum section: electronics / general

author: VintageTekFan
author_rank: Regular Contributor
timestamp: November 05, 2013, 01:31:48 am
content: Several years back I got more interested in microcontrollers, so I purchased a PIC18 Explorer board.I used it a total of 2 times, and put it into its original storage. A couple years later, I decide to bring it out again for another project, and I can't program it. Target ID (0) mismatch. All my research online says that the PIC is burned out, bummer.So I figure I'll start tracing signals from the programmer, since I can verify that works. First signal I try is Vpp. On this board, it routes through a jumper block, and a switch. I trace the Vpp signal to the switch. But no further. Not in any position of the switch. So after two uses of the switch, it's bad.So I jump out the switch, and lo and behold, it works! Just the damn switch was the problem.I load up the demo code. And the built in LCD is crapped out. I'm calling it quits on this for tonight.

author: AlfBaz
author_rank: Super Contributor
timestamp: November 05, 2013, 02:01:35 am
content: Unlucky I guess.I've had an explorer 16 board with a number of mcu daughter boards for years. The damn thing just wont die and I hang a lot of dodgy shit off it

author: JTR
author_rank: Regular Contributor
timestamp: November 05, 2013, 01:59:57 pm
content: Are you sure that it is not just the LCD contrast setting? The times I have seen long forum threads on LCD code not working when it just turned out to be a tweak of the contrast pot.

author: VintageTekFan
author_rank: Regular Contributor
timestamp: November 05, 2013, 06:45:45 pm
content: Quote from: JTR on November 05, 2013, 01:59:57 pmFairly certain - there are missing lines in random vertical and horizontal planes.Looking at the display, it is a glass substrate on a foam tape strip, so any pressure could easily torque the board. But a replacement display appears cheap on Digikey (8.35 USD). I may just replace it. I have since replaced the failed switch with jumpers, too.At least I got the thing working again.I'm planning on using it to develop an interface to a Motorola M12+T for a GPSDO, but thats another thread.
VHDL FPGA System design resources  - Page 1
Forum section: electronics / general

author: Harvs
author_rank: Super Contributor
timestamp: October 16, 2013, 03:04:22 am
content: I'm at the stage where I know the basics of VHDL and digital logic design. Probably at the level you'd expect of a graduate EE.I'm looking to learn more about taking a somewhat complex requirement, say a non-trivial bus, and implementing it without it becoming a mess.There is truck loads out there on this for sequential languages (e.g. C/C++), where there's all sorts of strategies for breaking down a requirement into segments based on various things and then applying OO principles etc. Then clean coding principles to ensure your code is self descriptive and maintainable.I haven't been able to find anything for hardware descriptive languages yet. And the books I've read tend to somewhat arbitrarily assign functionality to modules without any discussion on why they chose to do it that way.Any thoughts?

author: TerminalJack505
author_rank: Super Contributor
timestamp: October 16, 2013, 03:56:20 am
content: I ran across some documents a couple years back that propose something called 'structured VHDL'.Document 1,document 2,document 3.You might check them out. I don't do enough VHDL coding to really know whether or not that's a good way to write VHDL. There might be issues with the synthesized code (less optimized, for example) since it is more abstract than the 'data flow' method.I played around and came up with an object-oriented style of template that is based on Mike Treseler's 'two process' method. The attached file is an example of this.

author: Harvs
author_rank: Super Contributor
timestamp: October 16, 2013, 04:57:42 am
content: I have to laugh at the analogy made in that first docQuoteRing any bells with OSH schematic trends these days?

author: Kohanbash
author_rank: Regular Contributor
timestamp: November 01, 2013, 01:40:20 pm
content: I think once you are comfortable with the basics of an HDL the next step is to become familiar with a toolset.A lot of FPGA development is based on knowing the tools and flow to create a design from scratch. This includes pin placement, timing, and using existing IP.If you are interested in doing embedded processor work then you need to learn how to connect all the IP, create IP, and work with registers between the hardware and software layer.Hope that helps.

author: nctnico
author_rank: Super Contributor
timestamp: November 01, 2013, 04:04:49 pm
content: Quote from: Harvs on October 16, 2013, 04:57:42 amIMHO thinking in terms of diagrams, gates and logic chips is a bad start. If you develop software you don't start with drawing a diagram... So adopt software development methods for writing HDL.
How to reduce the data rate?(OV7670 + AL422B(FIFO) Camera Module) - Page 1
Forum section: electronics / general

author: rozeh
author_rank: Regular Contributor
timestamp: October 08, 2013, 06:05:52 am
content: i bought this module:OV7670 + AL422B(FIFO) Camera Moduleand i want to send the live video of the camera by thisNRF24L01but i have a problem.I don't know is the RF module suitable(NRF24L01) for this job?I think the data rate of the NRF24L01 isn't enough for camera. what's your opinion?If you agree with me, in your opinion, how can I solve this problem?(in other word, can I reduce the size of the camera's data(video)?)I should send the video by NRF24L01 for 1Mbps or more. in addition, I use of the ST32F103RET6 for this job.if the information is not enough, please ask me your question untill answer to you.also, i have already asked my questionhere

author: saigai
author_rank: Contributor
timestamp: October 09, 2013, 05:54:50 am
content: Since the image is captured in the FIFO, you can proceed to send the image forward as slowly as you like. I've done it via normal usb/serial adapter myself..After this, It's up to debate wether the stream should be called a slideshow instead of video...

author: rozeh
author_rank: Regular Contributor
timestamp: October 13, 2013, 11:13:46 am
content: Thanks a lot for reply. by which MCU you do it?

author: saigai
author_rank: Contributor
timestamp: October 22, 2013, 05:38:10 pm
content: Quote from: rozeh on October 13, 2013, 11:13:46 amI used msp430 to transfer the image at a ridiculously slow speed. This is not an useful application of the camera, but demonstrates well that there's no need to "reduce the data rate", as the data rate is completely up to you.More details here:http://www.rpg.fi/desaster/blog/2012/10/20/ov7670-fifo-msp430-launchpad/Your actual question is probably if the NRF24L01 can be used to transfer images at a high enough speed to call it video. Unfortunately I have no idea.

author: Jeroen3
author_rank: Super Contributor
timestamp: October 31, 2013, 03:37:45 pm
content: They claim to have 2 Mbps air data rate.If on a sunny day you actually reach half of that, you'll have about 150 KB or Kpixel per second of a grayscale image.Thats about 0.4 fps.If you MCU can handle that.
looking for a blackfin dsp board with ethernet onboard - Page 1
Forum section: electronics / general

author: legacy
author_rank: Super Contributor
timestamp: October 25, 2013, 09:38:46 pm
content: hii have bought an ANALOG DEVICES ADZS-BF537-EZLITE EVAL board, which is blackfin + ethernet (+ uart)unfortunately the board is very very big and i need something smaller, anything around on the market ?edit:there is also ANALOG DEVICES ADZS-BF537-STAMP, but is too big too

author: enz
author_rank: Regular Contributor
timestamp: October 26, 2013, 08:44:23 am
content: Maybe this site is worth a look:http://ww2.bluetechnix.com/en/bluetechnix/home/(click on "Tiny Boards")

author: legacy
author_rank: Super Contributor
timestamp: October 26, 2013, 04:54:26 pm
content: interestingprice list

author: codeboy2k
author_rank: Super Contributor
timestamp: October 26, 2013, 06:24:20 pm
content: Quote from: legacy on October 26, 2013, 04:54:26 pmwhat did you find interesting?

author: Alexei.Polkhanov
author_rank: Frequent Contributor
timestamp: October 27, 2013, 01:39:49 am
content: Those Bluetechnix boards are not small, they are "miniaturized" hence the premium pricing ... Probably 8+ layer PCB?

author: senso
author_rank: Frequent Contributor
timestamp: October 27, 2013, 03:33:28 am
content: QuoteNice, support paid by the questions, weeds out all the stupid questions right of the bat

author: nctnico
author_rank: Super Contributor
timestamp: October 27, 2013, 11:23:47 am
content: In my experience Bleutechnix isn't very strick about 3 support questions. The documentation on their website isn't always up-to-date.

author: legacy
author_rank: Super Contributor
timestamp: October 29, 2013, 12:46:12 am
content: I found a board around with BD537 on it, unfortunately it has no bootloader, so an other problem is to get a serial bootloader for blacken, or an ethernet bootloader, i am thinking about uboot but it is too big for its tiny serial boot flash ='(
Verilog newbie help - Page 1
Forum section: electronics / general

author: jeremy
author_rank: Super Contributor
timestamp: October 26, 2013, 10:18:48 pm
content: Hi guys,I've been trying to learn verilog lately, and my latest project is to build a serial port echo device. I'm a bit stuck working out how to proceed to the next stage of my design.I've tested both RX and TX modules separately and they work just fine (I'm using the ones fromhere). I am having trouble putting together a one-shot system that will trigger the data transmit. Basically, RxD_data_ready is high when the module is not receiving data, so I'd like to pulse the transmit line. However, every time I try to implement a flag like has_sent_data, I get multiple driver errors. I understand why these are there, but I don't really know how to get around them. Can anyone give me a hint?My current code is attached (snipped a little to keep it short):Code:wire ready_to_read = rxd & ~txd_busy;async_receiver asr(.clk(clk), .RxD_data_ready(rxd), .RxD_data(rxd_data), .RxD(avr_tx));async_transmitter ast(.clk(clk), .TxD_start(txd_start), .TxD_data(led), .TxD(avr_rx), .TxD_busy(txd_busy));always @(ready_to_read)beginled <= rxd_data;if (has_sent == 0)beginhas_sent <= 1'b1; // this is the multiple driver problemtxd_start <= 1'b1;endendalways @(posedge clk)beginif (current_data != rxd_data)beginhas_sent <= 1'b0; // this is the multiple driver problemcurrent_data <= rxd_data;endend

author: codeboy2k
author_rank: Super Contributor
timestamp: October 27, 2013, 01:39:14 am
content: Instead of the always@(ready_to_read) block, why not just move all that down into the always@(posedge clk) block and test for ready_to_read with a simple if statement. It will be synchronous to the clock now, and no more multiple drivers.

author: jeremy
author_rank: Super Contributor
timestamp: October 27, 2013, 03:46:00 am
content: Yep, that fixed it. I suppose that thinking about it now, the rxd signal is synched with the clock anyway...

author: codeboy2k
author_rank: Super Contributor
timestamp: October 28, 2013, 01:26:04 am
content: Quote from: jeremy on October 27, 2013, 03:46:00 amGood that it fixed it. Yes, I was thinking the same too.. that at least one of the two signals rxd or txd_busy was already synchronous to the clock anyways, so just bring it all into the one process block synchronous to the clk edge.
A 16 Pin DIL Micro controller with VDD on Pin16 and Vss on Pin8 - Page 1
Forum section: electronics / general

author: Clint
author_rank: Regular Contributor
timestamp: October 26, 2013, 08:38:20 pm
content: Any Idea where I might get an MCU that fits this spec 16 Pin Total DIL Device.Need VDD on Pin 16 and VSS on Pin 8 to match a current part, only doing binary conversion with all other pins.Cheers

author: Kjelt
author_rank: Super Contributor
timestamp: October 26, 2013, 09:11:38 pm
content: Why not choose any microcontroller that you already know and have the tools for and design a conversion pcb to a dil 16 socket?The VDD and GND fixed on two pins and all the other pins free for I/O is a difficult requirement, because it implies:- that the uC has it's own clock source.- the uC has no external reset pin which at itself is already quite rare.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: October 26, 2013, 09:15:58 pm
content: Quote from: Kjelt on October 26, 2013, 09:11:38 pmSeveral MCUs have internal clock and internal reset as options - e.g. almost all PICs.16 pins isn't very common though - you may end up needing to do an adaptor PCB, or maybe using an 18 or 20 pin one with some pins and a wire or 2 cut short.

author: Unknown
author_rank: Unknown
timestamp: October 27, 2013, 02:49:59 pm
content: But at that point you don't have to care about pinout anymore either, so you might as well pick any micro available in SOIC with > 18+ pins. Almost all of them will have at least 14 GPIO pins.
TL866 and vintage eproms - Page 1
Forum section: electronics / general

author: Ericho
author_rank: Regular Contributor
timestamp: October 26, 2013, 10:30:48 am
content: Hi,I'm restoring an old Williams pinball machine and to trouble shoot it I tryed to bake a 2716 testrom in a tl866 programmer.Althou the programmer supports ST M2716 eproms, in reality it does not. The data sheet shows these old eproms need a 25V VPP and the TL866 goes to 21V VPPReading is not a problem.27c16 eproms are not a problem to program in a tl866I found some NMC27C16BQE-200 on ebay and with a 12.5V VPP. this works fine in the TL866aJust wanted to share this trap with this forum, better to verify the data sheets then to believe the support list of the tl866 (when dealing with vitage eproms)Kind regards,Eric
AT89S52 Question about Ports - Page 1
Forum section: electronics / general

author: Kurtsta
author_rank: Newbie
timestamp: October 29, 2013, 05:55:26 am
content: Hello,Being relatively a beginner when it comes to electronics, there are just some things that confuse the hell out of me...Is anyone able to explain to me what this sentence means:"As inputs, Port 1 pins that are externally being pulled low will source current (IIL) because of the internal pull-ups."If more context is required, the paragraph containing this sentence can be found on page 4 of the AT89S52 datasheet.

author: amyk
author_rank: Super Contributor
timestamp: October 29, 2013, 05:58:48 am
content: It means there are resistors from the pins to the positive supply rail, so if you connect one of the pins to ground, current will flow out of them.

author: Kurtsta
author_rank: Newbie
timestamp: October 29, 2013, 07:10:08 am
content: Ok, that makes more sense. When you say "so if you connect one of the pins to ground, current will flow out of them." do you mean it must be connected directly to ground, or can a load (perhaps a 7-segment LED display) be placed between the pin and ground?

author: Psi
author_rank: Super Contributor
timestamp: October 29, 2013, 07:39:16 am
content: The pin will naturally rise to VCC because of the pullup.Any attempt to lower the voltage on the pin (like connecting a load) will cause some current to flow from VCC through the internal pullup and out of the mcu pin.Pullup resistors inside a MCU are very large, usually around 50k, so the max current you can get out is 5v VCC / 50,000 ohms = 0.0001A or 0.1mAThe current too small to light up an LED.You may see a very faint glow in a dark room.But why would you want to connect an LED to an input?

author: westfw
author_rank: Super Contributor
timestamp: October 30, 2013, 02:08:33 am
content: QuoteThe 8051 microprocessors don't have the sort of IO ports you're used to on more modern processors. They're "bi-directional" open-drain outputs; you can write 0s and the pins will sink substantial current, or you can write 1s in which case the internal pullup allow the pins to be pulled down by an external signal (and read as 0.) You don't get high-impedance, and you don't get much source current.To connect an LED, put it between VCC and the pin, rather than between the pin and GND, and reverse your logic (outputting 0 turns the LED on.)

author: amyk
author_rank: Super Contributor
timestamp: October 30, 2013, 11:21:27 am
content: Quote from: Psi on October 29, 2013, 07:39:16 amHigh brightness LEDs start glowing visbly at a few uA, and are quite noticeable at 100uA...

author: Kurtsta
author_rank: Newbie
timestamp: October 30, 2013, 11:41:11 am
content: Thanks heaps to everyone for the information that you have provided. Everything is starting to make more sense now
TFT LCD pinout help  - Page 1
Forum section: electronics / general

author: odell
author_rank: Contributor
timestamp: October 26, 2013, 04:37:30 am
content: I need some help with a TFT LCD driver board pinout. The LCD is a 7" inch TFT LCD module 800x480 SSD1963 w/touchpad PWM (link for the LCD would be below). The problem I'm having is I'm finding very little data for the driver board. I found a pinout to diagram for it. but that's basically what I found for it. if somebody can help me out with the name of the board or tell me what the abbreviations mean for the pinshere is the link for the LCDhttp://www.ebay.com/itm/7-inch-TFT-LCD-module-800x480-SSD1963-w-touchpad-PWM-arduino-AVR-STM32-ARM-/121017488870?pt=LH_DefaultDomain_0&hash=item

author: Harvs
author_rank: Super Contributor
timestamp: October 26, 2013, 05:02:00 am
content: Did you notice that on that ebay page there's a download link for a ZIP file with everything in it?

author: odell
author_rank: Contributor
timestamp: October 26, 2013, 05:36:41 am
content: Quotealready looked at the download zip. nothings in there that I need. what I need is the 40 pin pin out diagram out of the LCD driver board and what the abbreviations mean on the pin out.

author: Harvs
author_rank: Super Contributor
timestamp: October 26, 2013, 08:32:07 am
content: Quote from: odell on October 26, 2013, 05:36:41 amHave another look. There's a schematic with all pins labelled and all IC's labelled.The datasheets for all those ICs are available by doing some googling.I've used an almost identical LCD before, but I don't think there's anything I could tell you that's not on that schematic.

author: David_AVD
author_rank: Super Contributor
timestamp: October 26, 2013, 08:55:49 am
content: The pin names are pretty much the same for all those type of LCDs. There's usually descriptions in the example code. Download the SSD1963 data sheet as well.
ARM Cortex-M Online MOOC class... - Page 1
Forum section: electronics / general

author: grego
author_rank: Frequent Contributor
timestamp: October 24, 2013, 03:44:50 pm
content: Anyone who's interested, Jon Valvano (professor at University of Texas/Austin for comp-e) is moving one class to a MOOC format:https://www.edx.org/course/utaustin/ut-6-01x/embedded-systems-shape-world/1172If you're interested in learning something new you might consider checking it out. I'm not affiliated (and there's no cost for the class anyway unless you buy the lab components which he gives you the BOM for) but though folks might be interested.

author: Kremmen
author_rank: Super Contributor
timestamp: October 24, 2013, 07:31:24 pm
content: Already enrolled
In your experience, what RTOS is the best for PIC32? - Page 1
Forum section: electronics / general

author: m4l490n
author_rank: Contributor
timestamp: October 18, 2013, 07:28:58 pm
content: Hello everybodyBased in your experience, what RTOS performs better in the PIC32? I'm currently starting to use FreeRTOS but I don't know if this is the best RTOS for PIC32. I have seen some kind of benchmarking results between RTOSes here:http://www.microchip.com/forums/tm.aspx?m=279201But I don't really trust in that kind of things. I'm looking for someone that had actually worked with one or several RTOSses and share their experience about what RTOS is the best for the PIC32 according to the projects in which you have deployed the RTOS.Also I think that this kind of experience/knowledge will be very useful not jut for me.Best Regards!!

author: andersm
author_rank: Super Contributor
timestamp: October 19, 2013, 03:08:07 pm
content: How likely is RTOS performance to be a real issue? If it is, then I would think that either you've designed your application badly, or you've selected an unsuitable hardware platform.If you still think it's a big factor in selecting your RTOS, you candownload the benchmarkand compare yourself.

author: tszaboo
author_rank: Super Contributor
timestamp: October 23, 2013, 12:10:56 pm
content: Few years back, I was working with a self-written, non preemptive basic RTOS based on the uC. Task switching was made in assembly, and we used static memory. It is not all that hard to write one, based on your requirements. But of course I was working with talented people who know programming much better than me.
can a CPLD work like a DG413 analog switch? - Page 1
Forum section: electronics / general

author: grips03
author_rank: Contributor
timestamp: October 22, 2013, 03:49:09 am
content: I have a project that uses 2x DG413 analog switch and 3 74xx series logic gates. I know I can replace the 3 74xx with a CPLD and I've done that before and most likely will do it here again.However can a CPLD also work like an analog switch? The each analog switch offers 3 paths between two wires. Each path has a different resistance, the analog switch allows the right path to be selected based on the input.

author: mrflibble
author_rank: Super Contributor
timestamp: October 22, 2013, 04:22:59 am
content: I seriously doubt it. Switches like the DG413 are reasonably low resistance bi-directional switches with low charge injection. I don't see how you're going to duplicate that using a CPLD. If the question is "can any random CPLD do everything I can do with an DG413?" then the answer is no. If you have very relaxed requirements, then maybe. But assuming the DG413 is there for a reason, that's not too likely...

author: grips03
author_rank: Contributor
timestamp: October 22, 2013, 04:55:41 am
content: good to know CPLD can't act like analog switch.I wish Dave would do a show on what can and can not be built using CPLDs. For logic stuff they are awesome. Perhaps because that is what they are designed for

author: Stonent
author_rank: Super Contributor
timestamp: October 22, 2013, 07:37:49 am
content: I would assume anything analog is a no-go for a CPLD or FGPA, because you're building on logic devices, 1's and 0's, arrays of transistors etc.

author: amyk
author_rank: Super Contributor
timestamp: October 22, 2013, 10:16:22 am
content: Some digital ICs can be forced to work in linear mode (e.g. CD4000 series being used as audio amps) but they will draw more power, possibly to the point of failure.

author: Laurynas
author_rank: Contributor
timestamp: October 22, 2013, 12:40:01 pm
content: PSoC could be an answer here. CPLD capabilities + configurable analog.you can leave PSoC's MCU sleeping if you don't need it

author: free_electron
author_rank: Super Contributor
timestamp: October 22, 2013, 12:48:06 pm
content: Cpld Complex Programmable LOGIC Device.Clear now ?
Interfacing SRAM with Basys 2 - Page 1
Forum section: electronics / general

author: wornwinter
author_rank: Newbie
timestamp: October 28, 2013, 08:56:51 am
content: Hey guys.I've been getting my feet wet with the Basys 2, managed to get to grips with VHDL, and write a simple pong game from scratch. Although I've been trying to interface it with an SRAM chip, the one at the following link:http://uk.farnell.com/jsp/search/productdetail.jsp?SKU=1562896Unfortunately, it hasn't been going well. I've yet to actually do anything with the chip other than power it on! Does any one have any example VHDL, or even some reading material that might help me? I've been doing more or less everything that the SRAM datasheet specifies, but I think the problem lies with my timing... I'm still trying to learn that.Thanks a lot!
STM32F4 Disco VCP USB example - Page 1
Forum section: electronics / general

author: Harvs
author_rank: Super Contributor
timestamp: October 18, 2013, 12:33:17 am
content: For anyone wanting to get a virtual comm port up an running on the Disco board I've attached an example. You'll need the ST USB library "STM32_USB-Host-Device_Lib_V2.1.0" and the standard peripheral libraries. I've just provided a screenshot from keil of the files included in the project since I know most don't use Keil, therefore attaching the project would be pointless.This is nothing more than the ST VCP to UART bridge example with the UART stuff removed, the pin and clock configurations sorted out for the disco board, and the hundreds and hundreds (maybe thousands?) of lines of extra stuff for all their other boards and auto documentation removed. Seriously their example is like wading through a sea to find the relevant code.You've got two functions of significance in the usbd_cdc_vcp.c file.uint16_t VCP_DataTx (uint8_t* Buf, uint32_t Len)uint16_t VCP_DataRx (uint8_t* Buf, uint32_t Len)They're pretty obvious, you need to implement whatever you want to add data to the IN buffer, and process data from the OUT buffer.In this example I've got a counter in the main function which adds an ascii string of the current count every overflow, and a case statement turning a led on and off in the Rx section.Hopefully this may save you some time...
Free seminar about driving an TFT LCD with STM32 by ST Electronics - Page 1
Forum section: electronics / general

author: silent
author_rank: Contributor
timestamp: October 14, 2013, 11:53:39 pm
content: Hello.I think it might be worth looking:http://www.st.com/web/en/seminar/Efficient_driving_TFT_LCD_STM32F429ST is organizing a free 1-day seminar in 18 locations between october and december. There will be a seminar and a practical session which might be nice. They will also give away STM32F4x9 discovery kits to play with it the LCD at home.Is anyone signed up already? ;-)

author: dannyf
author_rank: Super Contributor
timestamp: October 15, 2013, 12:00:06 am
content: The part on emWin would be quite interesting.

author: Stonent
author_rank: Super Contributor
timestamp: October 15, 2013, 12:00:33 am
content: There's a decent sized ST facility in my part of Texas about 20 minutes away, odd that they didn't use that for this.

author: AlfBaz
author_rank: Super Contributor
timestamp: October 15, 2013, 12:22:46 am
content: It sucks to be in OZ

author: Stonent
author_rank: Super Contributor
timestamp: October 15, 2013, 12:27:01 am
content: Quote from: AlfBaz on October 15, 2013, 12:22:46 amBut there are flying monkeys in Oz!

author: MadElectron
author_rank: Newbie
timestamp: October 16, 2013, 11:22:13 am
content: Quote from: silent on October 14, 2013, 11:53:39 pmThanks for the tip!Signed up here in Germany.

author: chris0822
author_rank: Newbie
timestamp: October 16, 2013, 05:33:29 pm
content: QuoteI second this, appreciate you bringing it up. I attended one of these ST Seminars about a year ago on their low power parts and I highly recommend it. Plus you get a really nice free lunch.There is one in the US using the same dev boards, I just signed up for if anyone is interested:http://www.st.com/web/en/learning/seminar/STM32_F4_Cortex_M4_MCU_Seminars

author: Dongulus
author_rank: Regular Contributor
timestamp: October 16, 2013, 06:52:42 pm
content: Quote from: chris0822 on October 16, 2013, 05:33:29 pmI'm considering one in San Diego. I can't think of any applications for this microcontroller in any of the projects in my department though. I don't know if I could convince anyone at work that attending is for work related purposes.

author: chris0822
author_rank: Newbie
timestamp: October 16, 2013, 11:03:57 pm
content: QuoteThe seminar in Philadelphia that I attended was useful for picking up some tips/tricks in working with the Keil compiler during the hands on session. They gave you a nifty RFID development board that could power their low power chip wirelessly through the RFID radio.This upcoming seminar looks like it includes another nice dev board. We use STM32F4's for various projects where I work so going to this one is probably justified to see what's new. The first half of the seminar is sitting through their marketing pitch on ST.
Topic unknown - Page 1
Forum section: electronics / general

author: biiçh
author_rank: Newbie
timestamp: October 18, 2013, 12:02:45 pm
content: .User was not happy with the first response and has deleted their post

author: tszaboo
author_rank: Super Contributor
timestamp: October 18, 2013, 12:21:08 pm
content: Yes, there is probably someone. Sorry, stupid question -> stupid answer.I'm curious although. What on earth are you trying to control with a PID on a LED?
13,56 MHz RFID in software - Page 1
Forum section: electronics / general

author: Tost
author_rank: Contributor
timestamp: October 04, 2013, 10:45:00 am
content: Some people emulated 125 kHz-RFID-tags with just a coil connected to a small 8-bit µC. Does that theoretically work for 13,56 MHz Mifare-Classic in a similar way? May be with some additional passives to realize the load modulation? If I get it correctly there are much more clock cycles available compared to the 125 kHz version. The 847.5 kHz subcarrier may generated by hardware pwm.

author: NoNRG
author_rank: Newbie
timestamp: October 07, 2013, 04:42:53 am
content: 13.56 MHz is used for NFC communication. You might try researching examples using NFC.Here's a quick example of automatic impedance matching different antennas for use with 13.56 MHz.http://www.nfc-research.at/fileadmin/papers/2008/14/2008_07_23_csndsp08.pdf

author: dpavlin
author_rank: Newbie
timestamp: October 07, 2013, 01:39:16 pm
content: It dies indeed work for 13.56 MHz Mifare tags. Chameleon project athttp://sourceforge.net/p/chameleon14443/home/Home/implementats it using AVR to create emulator for ISO 14443 contactless smartcards. As additional bonus, it's open hardware project together with eagle schematics, board and documentation.

author: Tost
author_rank: Contributor
timestamp: October 13, 2013, 07:23:01 pm
content: Great! That was exactly was I looking for. Thanks a lot dpavlin.
Why not so many HC908 .asm projects? - Page 1
Forum section: electronics / general

author: Circlotron
author_rank: Super Contributor
timestamp: October 13, 2013, 01:06:54 am
content: Everywhere I look people are doing stuff with pics and avrs and stuff I never heard of. I do all my stuff in assembler on Motorola HC908 micros. Okay, so assembler might not be the language of choice for everyone, but if one is using assembler, what is the attraction for other micros, especially pic?

author: ataradov
author_rank: Super Contributor
timestamp: October 13, 2013, 01:20:25 am
content: It probably has something to do with overall popularity of the Motorola MCUs. I honestly was sure that HC08 is dead, so I had to go to digikey and check. They seem to to be more expensive and are not so rich on peripherals.

author: AlfBaz
author_rank: Super Contributor
timestamp: October 13, 2013, 01:21:40 am
content: probably the eco system that you find lacking on the HC908 ie. a large code base, large community, plenty of support etc

author: Marco
author_rank: Super Contributor
timestamp: October 13, 2013, 03:12:17 am
content: HC08 was popular, a decade ago before any of the manufacturers really started to get hobbyist focused ... PIC was first, then AVR. It's hard to make a dent in PIC/AVR's first mover advantage without a whole lot of PR (like TI and to a lesser extent ST have done).As for HC08, I don't think Freescale even has a low cost starter kit for it ... it's basically in the same boat as 8051 and 6502.

author: westfw
author_rank: Super Contributor
timestamp: October 13, 2013, 05:16:36 am
content: For a long time, the Motorola microcontrollers were difficult to purchase in anything smaller than "production" quantities. IIRC, they were also relatively late to Flash technology, leaving the "reprogrammable" category to (very expensive) UV-erasable parts.

author: amyk
author_rank: Super Contributor
timestamp: October 13, 2013, 12:32:32 pm
content: They're not particularly hobbyist-friendly and Motorola/Freescale MCUs tend to be found more in automotive applications.
Why does the PIC slow down when I connect some current loads? - Page 1
Forum section: electronics / general

author: Tricka90
author_rank: Regular Contributor
timestamp: October 09, 2013, 08:02:40 am
content: I'm making a PIC controlled LED lamp. I'm noticing that every LED I add to the circuit the PIC program slows down more. Why is it happening and how can I work around this problem?I'm using a PIC 16F876 with 12MHz chrystal oscillator.If you need more information I'll be happy to give them.

author: ve7xen
author_rank: Super Contributor
timestamp: October 09, 2013, 08:31:08 am
content: Are you changing the code when you add an LED? If the PIC is clocked from a crystal it won't appreciably change speed just because you've changed the load on its IO pins. Something in your code has changed, or is behaving differently, when you're adding the LEDs.Posting your code may help.

author: dannyf
author_rank: Super Contributor
timestamp: October 09, 2013, 10:30:36 am
content: QuoteYou must be living in an alternate universe,.Seriously, what exactly did you observe that led you to that conclusion?

author: Psi
author_rank: Super Contributor
timestamp: October 09, 2013, 10:46:18 am
content: My guess is he's doing some sort of matrix or pwm

author: Jeroen3
author_rank: Super Contributor
timestamp: October 11, 2013, 08:19:06 pm
content: If you are running from internal oscillator, or any other external crystal which requires schmitt triggering, and the LED's are directly on the pic pins you might be exceeding maximum current limits.Causing voltage drop, causing oscillator artifacts.

author: WarSim
author_rank: Frequent Contributor
timestamp: October 11, 2013, 10:17:34 pm
content: Quote from: Jeroen3 on October 11, 2013, 08:19:06 pmI agree with your assessment. All PIC FRCs have voltage for speed requirements. You may be browning out the chip slowing the FRC OSC or even triggering the BOR whenever you turn on too many LEDs. Either way it is starving for attention (pun). :-)

author: dannyf
author_rank: Super Contributor
timestamp: October 11, 2013, 10:35:25 pm
content: QuoteYes, likely polling.
Board to board connector - Page 1
Forum section: electronics / general

author: fagiano
author_rank: Regular Contributor
timestamp: October 08, 2013, 05:09:05 pm
content: Hi, I have too choose a connector to link 2 boards together, the signals will be 3.3V logic at no more than 150/200Mhz, is it ok to just use an 2.54mm IDC connector or I should be looking at something more exotic? Are ribbon cables an ok at this speeds?thank you in advanceciaoAlberto

author: marshallh
author_rank: Unknown
timestamp: October 08, 2013, 07:02:51 pm
content: How many signals? Single ended or diff pairs? How long is the distance, can you make them overlap within 2cm?Ye olde pin header cables are not really a good fit at this speed.Also important are return paths (every other conductor is ground e.g. ATA-100) and termination.

author: fagiano
author_rank: Regular Contributor
timestamp: October 09, 2013, 04:08:51 pm
content: I have ~30 signals plus power, no differential pairs. I can skip the ribbon cable and do a board to board connection. I was just wondering if a cable would work. It's a little bit easier to move it around the bench but is not essential if it ends up being too much trouble.thank youAlberto

author: tszaboo
author_rank: Super Contributor
timestamp: October 09, 2013, 05:51:36 pm
content: Samtechttp://www.samtec.com/has detailed specifications and measurements in the GHZ+ region for most connectors. Read a bit. I would suggest to use a LOT of GND pins.
AVR Dragon and ATmega32U4 - Page 1
Forum section: electronics / general

author: vj90
author_rank: Newbie
timestamp: October 08, 2013, 03:02:17 am
content: I am an EE student and I have a little of experience with the MSP430, just the very basics.I want to get started and get experience on my own. I have project in mind and I have been investigating and I have come to choose ATmega32U4 as the MCU that I am going to use. AVR Dragon would be the interface that I would use to debug/program.Now, I am not too sure how would I do this.How would I connect an ATmega32U4 (which comes in a TQFP 44 packaging) to the AVR Dragon?

author: Spikee
author_rank: Frequent Contributor
timestamp: October 08, 2013, 08:42:25 am
content: Via the ISP pins on the micro ? -> see datasheet and look for programming

author: form
author_rank: Contributor
timestamp: October 08, 2013, 05:42:53 pm
content: I think he means the bare micro.To program it that way you need an (expensive) TQFP-socket.The usual way is to program (or debug) it while it is soldered to your final PCB via an JTAG-pinheader.

author: fudgebobs
author_rank: Contributor
timestamp: October 08, 2013, 08:16:05 pm
content: Quote from: vj90 on October 08, 2013, 03:02:17 amSurface mounts can be a real pain. I found this site last year doing a project which helped me out tons:http://www.proto-advantage.com/store/They are based off Ontario, Canada. They basically sell breakout boards for various surface mount packages. They break them out into standard 2.54'' spaced slots. You can then solder male or female header breakouts and wire them to the AVR Dragon.To see how to wire them to Dragon, take a look at the PDF guide that comes with the Dragon and also at the specific datasheet for the ATMega32U4.All the best.
Propeller chip in an Arduino form factor - ASC+ in the Zumo Robot - Page 1
Forum section: electronics / general

author: stempile
author_rank: Contributor
timestamp: October 08, 2013, 05:13:14 am
content: I am not the worlds greatest Spin (the native Propeller language) programmer, however same is true for C or C++ (The 8-core Propeller now has a C compiler with a Parallax supported IDE.)I live right down the street from Parallax in Northern California, USA so I have an extra fondness of the Propeller chip... On an impulse buy I picked up the Pololu Zumo robot chassishttp://www.pololu.com/catalog/product/2504with an Ardunio shield (motor control, IR sensors, compass, buzzer, button, Vreg). Happen to fit nicely with a local robot group contest.The ASC+http://www.parallax.com/product/32214snapped in perfectly and pinned out mostly as expected given an Arduino was used. I wrote several objects now on the Prop Object Exchange that took advantage of most of the shields components. What I like most is that I don't have to program based on interrupts.With the Zumo I start up a Cog (Propeller processor core, 8 total) and execute a state machine for motor PWM control. From the Main program I can simply pass variables to control direction and speed. In another cog I am able to start up a similar process to manage the 6 IR edge/line sensors and again simply read values through variables on the main program.I still have 5 unused cogs with my project - future will include an RGB LED Driver, extra sensors (sonar) and plan to make use of the compass. I may be adding encoders also.If folks are interested I can share more details of the project and some of the minor obstacles given ASC + --vs-- Ardunino challenges I had to resolve....
Simple way to export data from EEPROM through AVR. - Page 1
Forum section: electronics / general

author: fenclu
author_rank: Regular Contributor
timestamp: October 07, 2013, 01:48:09 pm
content: I'm designing a little data logger based on an ATMega8 which basically writes some values to an external EEPROM and then is supposed to export that data through USB. I know that the ATMega8 doesn't support USB. I think that the easiest way (from user's point of view) is to have the data saved as a .txt file on a mass storage device. I also know that it's pretty easy to do on an SD card using SPI. What's the easiest way to export my data through USB?

author: fenclu
author_rank: Regular Contributor
timestamp: October 07, 2013, 04:29:08 pm
content: Yeah, but will it work as a mass storage device?

author: dannyf
author_rank: Super Contributor
timestamp: October 07, 2013, 06:46:18 pm
content: QuoteQuoteWhich question are you working on? As they have different answers.

author: fenclu
author_rank: Regular Contributor
timestamp: October 07, 2013, 07:00:32 pm
content: There's one question, I just didn't make it clear enough. I want to know the easiest way to export data from AVR (with an external EEPROM) through USB.

author: dannyf
author_rank: Super Contributor
timestamp: October 07, 2013, 07:17:03 pm
content: QuoteThat's like asking what's the best way to travel the ocean in your wagon.You probably want to ask yourself which is more important to you: export data from the AVR or export data from the AVR through USB.You have an option to make your life a lot easier (or a lot harder if you go the other way).

author: Mr Smiley
author_rank: Frequent Contributor
timestamp: October 07, 2013, 07:20:44 pm
content: What I’d do, ( and do do on pics ) is either use, as mentioned above, the uart or bit bang to a single pin to a ttl><usb adaptor to a pc rs232 serial terminal which has the option of serial capture to file, then just open in a spread sheet.You can, in windows, map a serial com port to a usb port, also in Linux.On every byte sent also send a space or comma so the spread sheet can organize into rows/columns.So with your RS232 terminal running on your pc in capture to file mode, the pc connected to a ttl><usb adaptor serial link, the link Tx connected to a pin on your uart or whatever on your data logger, press a button on your data logger to initiate a serial stream and all will be captured.You only need a single pin plus ground for no handshaking serial.Or you could write your own dedicated pc end terminal in c and do whatever you want with the data.

author: fenclu
author_rank: Regular Contributor
timestamp: October 07, 2013, 07:37:28 pm
content: There's also the V-USB -http://www.obdev.at/products/vusb/index.htmlBut I somehow can't see it working for my purpose.