hybridfree/eevblog-posts huggingface dataset:
FT245RL weird behavior. Fakes? - Page 1
Forum section: electronics / general

author: meneerbeer
author_rank: Newbie
timestamp: November 02, 2015, 01:59:02 pm
content: Hi, first post here, not sure if this is the correct subforum for this.I recently bought some FT245RLs from China (I know bad idea) for some custom designed PCBs. The FT245RL is a USB to parallel FIFO. After receiving everything, I soldered some FT245RLs to my PCBs and of course, the circuit was not working.Ok, so I started debugging. I read out the FT245RL with FT PROG and it recognizes as a 'FT232R'. I asked someone with a similar (working) circuit) to read out his. His identifies as a 'FT245R'.The FT232R is a USB to serial converter. Therefore my next step was to figure out if my "FT245R" showed the same behavior as you would expect from a FT232R. I probed pin 1 with a logic analyzer, which is the TXD pin of an FT232R. I sent some data to the FT245RL and guess what I see on my logic analyzer, serial output:So at this point I can only conclude that the FT245RLs I received are disguised FT232RLs. I am in discussion with the supplier and I get the following respone: "Our FT245RL chips which is correct ones as we shipped,we have other clients who bought this item from us before,never have problem."The supplier seems to be asking me to cut off all pins of the ICs I received before I get my money back.. I want to be absolutely sure I am not doing something wrong before I do that. Am I missing something? Can the FT232RL for instance be easily reprogrammed to a FT245RL, which is why I am having problems with them? Why would you package FT232RLs as FT245RLs? That does not make any sense at all?

author: bktemp
author_rank: Super Contributor
timestamp: November 02, 2015, 02:22:32 pm
content: I had exactly the same problem some years ago. But my FT245RL were bought from Digikey, so it is unlikely they were fakes.My guess is, FTDI screwed up the labeling of the parts. Maybe FT232 and FT245 use the same silicon and the output interface is beeing configured at some step during production?Since all parts from one delivery behaved the same I got new parts.I have used the wrong FT245RL as FT232RL and they work fine, so they are fully functional FT232RL.Maybe the faulty labeled parts from Digikey/FTDI ended up in China and are now beeing sold there.

author: meneerbeer
author_rank: Newbie
timestamp: November 02, 2015, 02:34:58 pm
content: I sent FTDI an email to ask if they can confirm the misslabeling. Not sure if they would ever admit it..
Price of the HAPS platform - Page 1
Forum section: electronics / general

author: Fantasma25
author_rank: Regular Contributor
timestamp: October 30, 2015, 11:16:15 pm
content: Hello! I got curious about the super high end FPGA platforms for SoC prototyping and I stumbled upon the HAPS 70 and HAPS 80 from Synopsys. But does anybody knows how much do they cost? This is just out of curiosity, but I estimate that it's in the order of hundreds of thousands of dollars O0 hahaThanks!

author: janoc
author_rank: Super Contributor
timestamp: October 31, 2015, 01:25:16 am
content: The rule is simple - if you have to ask for the price you don't have the budget for it.

author: crispy_tofu
author_rank: Super Contributor
timestamp: October 31, 2015, 06:02:43 am
content: Quote from: janoc on October 31, 2015, 01:25:16 amYeah, the fact that there are no pricings available usually means they're mighty expensive
TI/NS EOL of old process is due! LTB now! - Page 1
Forum section: electronics / general

author: MT
author_rank: Super Contributor
timestamp: November 03, 2015, 06:35:03 pm
content: TI is retiring GFBA6 process, EOL for many devices.http://www.proaudiodesignforum.com/images/pdf/ti_20150901004_09292015_eol.pdfSome have replacements other not, that's life,we are all going to die some day!
Atmega328 PWM duty cicle - Page 1
Forum section: electronics / general

author: cosminnci
author_rank: Regular Contributor
timestamp: October 29, 2015, 08:50:30 am
content: I try to make a pwm with a 1,563 hz frequency but I have problems changing the duty cicle.Code:const byte n = 9;TCCR2A = bit (WGM20) | bit (WGM21) | bit (COM2B1);TCCR2B = bit (WGM22) | bit (CS22) | bit (CS21) | bit (CS20);OCR2A = n;OCR2B = ((n + 1) / 2) - 1; // 50% duty cycleI know OCR2B is 8 bit and 255 valuesbut according to above I can use only 9 steps of duty cicle.how can I use the full range of 255 steps and still have the 1,563 hz frequency?thank you.

author: Kalvin
author_rank: Super Contributor
timestamp: October 29, 2015, 09:01:48 am
content: Have you checked whether PWM-output mode "Toggle OC2A on Compare Match" would help?

author: Brutte
author_rank: Frequent Contributor
timestamp: October 29, 2015, 09:14:55 am
content: What about formatting your code? 75 posts and no advance so far..QuoteThe code does not match the comment, the comment does not match the code.

author: cosminnci
author_rank: Regular Contributor
timestamp: October 29, 2015, 09:19:24 am
content: ok, I edited the post, using the code tags.

author: obiwanjacobi
author_rank: Super Contributor
timestamp: October 29, 2015, 11:21:19 am
content: I don't see you setting the clock source / prescaler...?

author: cosminnci
author_rank: Regular Contributor
timestamp: October 29, 2015, 11:34:22 am
content: the bit (CS22) | bit (CS21) | bit (CS20) sets the prescaler to 1024

author: obiwanjacobi
author_rank: Super Contributor
timestamp: October 30, 2015, 02:26:32 pm
content: Ok setting the WGM20:2 bits will select FastPWM mode (chapter 17.7.3). Looking at the Waveform Generation Mode description (Table 17-8) it looks like it only works on Output Compare A. The full period (cycle) is mainly determined by the prescaler.So you should be setting the COM2A0:1 flags (not the COM2B) to output the signal. Do not forget to set the appropriate DDR register to set that pin to output - otherwise you will not see it (when pin is set to input).Not sure what the numbers are to get your desired frequency but the formulas are also in the datasheet.Hope it helps,Marc
Chibios and Event on Serial  - Page 1
Forum section: electronics / general

author: antoniolinux
author_rank: Newbie
timestamp: October 24, 2015, 10:22:43 am
content: hi to all, i'm newbie of embedded word i have this problem write this thread in chibiOSCode:static THD_WORKING_AREA(waRead5, 128);static THD_FUNCTION(Thread5,arg) {(void)arg;chRegSetThreadName("th_Buffer");palSetPadMode(GPIOA, 9, PAL_MODE_ALTERNATE(7));palSetPadMode(GPIOA, 10, PAL_MODE_ALTERNATE(7));sdStart(&SD1, NULL);event_listener_t Uart1Data;eventmask_t flags;chEvtRegisterMask((event_source_t *)chnGetEventSource(&SD1), &Uart1Data, EVENT_MASK(1));while (TRUE) {chEvtWaitAll(EVENT_MASK(1));flags =chEvtGetAndClearFlags(&Uart1Data);if (flags & CHN_INPUT_AVAILABLE){sdWrite(&SD2,"OK\r\n",4);}}}i want start a event when arrived data on SD1, in this code when arrive data on SD1 i write ok on SD2i have this strange situation if i press reset the board and later i press button i see the event but later this i don't see nothing,i use chEvtGetAndClearFlags for clear the flags but don't workcan you help me?best regardsA.

author: ralphd
author_rank: Frequent Contributor
timestamp: October 24, 2015, 10:59:12 pm
content: Can't offer any help but it is interesting to see some sample ChibiOS code. Seems overly complicated for basic IO.

author: photovore
author_rank: Newbie
timestamp: October 25, 2015, 03:32:14 am
content: You should post this in the CibiOS forum. The author, Giovanni, is very active there and can probably provide the most correct solution.

author: Jeroen3
author_rank: Super Contributor
timestamp: October 25, 2015, 04:26:57 pm
content: There is no need to explicitly subscribe to an event of the serial io queue.When you call sdRead you actually callCode:chIQReadTimeout(&(sdp)->iqueue, b, n, TIME_INFINITE)Which will wait indefinitely for data, there is also sdReadTimeout, which obviously only waits the specified timeout to allow the thread to read other events. Such as an request to kill itself.Yes, it is complicated. Especially when you start to dissect the code and find the ingenious method used for inheritance in C.

author: antoniolinux
author_rank: Newbie
timestamp: October 26, 2015, 10:27:38 am
content: Hi to all, hanks for your feedback, i fix it with this code:Code:static THD_WORKING_AREA(waRead5, 128);static THD_FUNCTION(Thread5,arg) {(void)arg;chRegSetThreadName("th_Riempio_Buffer");event_listener_t Uart1Data;eventmask_t activeEvents;eventflags_t flags;chEvtRegisterMask((event_source_t *)chnGetEventSource(&SD1), &Uart1Data, EVENT_MASK(1));while (TRUE) {activeEvents=chEvtWaitAll(EVENT_MASK(1));flags =chEvtGetAndClearFlags(&Uart1Data);if (flags){sdWrite(&SD2,"OK\r\n",4);}}return 0;}i see the problem is theCode:CHN_INPUT_AVAILABLEnoe i want to use the idea of Jeroen3Code:chIQReadTimeout(&(sdp)->iqueue, b, n, TIME_INFINITE)i hope this post can help other people.Best regardsA.
Comfile Technology A.K.A. CUBLOC - Page 1
Forum section: electronics / general

author: German_EE
author_rank: Super Contributor
timestamp: October 30, 2015, 08:44:10 am
content: Has anybody dealt with Comfile Technology recently? They produce and sell a useful range of 32-bit Floating Point micro controllers but:1) Their support forum has no messages later than 20142) Email messages to both sales and support in the USA get bounced back with error messages3) There is no reply when I email their head office in Korea.Have they been taken over or is the company dead, killed by an abundance of Arduino and Raspberry Pi?

author: crispy_tofu
author_rank: Super Contributor
timestamp: October 30, 2015, 09:46:35 am
content: It looks like they released an update for their development environment earlier this month, so it might be taking its dying breaths. Interestingly, there's no news articles about it either... talk about fading into obscurity

author: andersm
author_rank: Super Contributor
timestamp: October 30, 2015, 11:56:39 am
content: Quote from: blueskull on October 30, 2015, 09:57:05 amThey most likelyareusing ARM microcontrollers, they're just packaged into modules and running their proprietary software.

author: German_EE
author_rank: Super Contributor
timestamp: October 30, 2015, 05:53:35 pm
content: They use ARM processors in their modules but they're programmed in BASIC rather than C or C++, they also have a useful range of LCD screens with additions to the chip software to directly talk to them.As for the need for 32-bit floating point math, if you want to work out the tuning word for a DDS chip then the formula is(2^32 / Clock Frequency in Hz) x wanted frequency in Hz, not easy to do in eight bits. PICAXE have a 32-bit FP coprocessor but it's a lot of messing around and isn't too well integrated.
VHDL question (solved) - Page 1
Forum section: electronics / general

author: Dago
author_rank: Frequent Contributor
timestamp: October 24, 2015, 04:21:29 pm
content: I have an entity with a generic of type natural. Then I have a function which takes a natural number as an argument and returns a natural number. I then try to create a variable in the entity with such as "variable foo : unsigned(my_function(my_generic) downto 0);" and modelsim will complain "no feasible subprogram found" about the my_function call. I pretty much also tried different types for the generic and function return type/argument etc. but no dice. This function works fine when called with for example some_other_variable'length but not with the generic.What is happening?Edit: Gah solved, I had an enumerated type the same name and I didn't realize this due to case insensitiveness...
PLCC-52 - Page 1
Forum section: electronics / general

author: kfc_n
author_rank: Contributor
timestamp: October 22, 2015, 05:54:34 am
content: Good day friends!I need help, Can anyone here suggest a 52pin PLCC that can replace an ATMEGA2560, I'm trying to make a PCB that would make changing of MCU easy. Unlike ATMEGA2560 which is really hard to troubleshoot.Thanks and Regards,Karl

author: ale500
author_rank: Frequent Contributor
timestamp: October 22, 2015, 06:34:06 am
content: You could make an adapter TQFP-64 to PLCC-52, Make it better PLCC-68, it is a bit bigger

author: kfc_n
author_rank: Contributor
timestamp: October 22, 2015, 06:48:01 am
content: Thanks for the quick reply buddy! I've done that for testing, but now, is there a counterpart of ATMEGA2560, with regards to specs, that is a PLCC type?

author: Jope
author_rank: Regular Contributor
timestamp: October 22, 2015, 08:27:15 am
content: Quote from: kfc_n on October 22, 2015, 06:48:01 amNo. PLCC packages are basically obsolete when it comes to modern ICs. If you look at Mouser, you will not find a single 16- or 32-bit microcontroller in this package. You will find some 8-bit µCs in PLCC, granddaddies like HC11s, 8051s, etc.; also some PICs. The only Atmel AVRs in PLCC are the ATmega8515 and ATmega8535.I am not sure what the whole point is. Why do you want to a socket in the first place? Is this supposed to be a development board? There are QFP sockets; not cheap though... And desoldering a QFP part is also not rocket science these days.

author: Ian.M
author_rank: Super Contributor
timestamp: October 22, 2015, 09:10:05 am
content: If its to make it easy to change the MCU on a development board, put a SMD part on a daughter card, with any other support components it needs really close to it (e.g. decoupling). You can also remap the connections to suit different MCU pinouts.

author: nctnico
author_rank: Super Contributor
timestamp: October 22, 2015, 09:52:36 am
content: Quote from: Ian.M on October 22, 2015, 09:10:05 amGo one step further: buy a pre-made module with 2.54mm spaced pins.
ARM with a dual switched regulator - Page 1
Forum section: electronics / general

author: brucebertrand
author_rank: Newbie
timestamp: October 21, 2015, 01:52:41 am
content: I'm looking at running an ARM micro and a few other devices on a board with an LTC3558, which has both buck and buck-boost regulated outputs. The buck-boost appears to be the four-switch type (non-inverting).Everything should run happily with a single 3.3V supply. Even though the ARM will work down to 1.8V, at least one device on the board has a dropout voltage of just under 3.3V. I'm planning on using a single LiPo cell to power the device, and would like to eek out as much runtime from it as possible. The entire project will draw around 100mA max, but with the possibility of frequent sleep periods on the micro and other devices, during which I might see something like 5 to 15mA total draw. I'm looking at LiPo cells in the neighborhood of 1000mAh.Considering the voltage requirements, I'm assuming that I'll need to use the buck-boost regulated output of the 3558.My question is this: Is there any reason I should even think about using the buck regulated output?Is there really a significant improvement in efficiency with buck topology vs buck-boost?Should I just run the micro on the buck and have it sit at 1.8 while everything else is at 3.3 on the buck-boost? (FWIW, I'm pretty new to this stuff, so this might be a big can-o-worms that I'm not quite ready for...)Should I come up with a single 3.3V rail topology that switches from the buck to the buck-boost at a threshold voltage?Thanks in advance!

author: nctnico
author_rank: Super Contributor
timestamp: October 21, 2015, 09:33:59 am
content: Just do the math when using a switcher versus a linear regulator! A switcher uses a few mA at least so it is likely not the best choice for powering a circuit which needs less than 100mA.

author: mark03
author_rank: Frequent Contributor
timestamp: October 21, 2015, 06:06:04 pm
content: I'm not sure there is much point in buck-boost from single-cell lithium ion, as there is not much recoverable energy from the cell below 3.2V (which your "3.3V" rail could drop to without the system failing).But as nctnico said, you just need to do the math. I would amend what he said, though, in that you can get switchers made specifically for low-power operation, maintaining reasonable efficiency down into the 1-10 mA region, with quiescent current far below a few mA. Just go to TI's web site, drill down to buck regulators with integrated switch, and have a look at the available Iq given your other requirements for packaging, input/output voltages, etc.Another factor, somewhat counter-intuitive, is that micros with a large supply range usually draw less current at, say, 1.8V, than they do at 3.3V. This means that even if you obtain the micro's rail from a linear regulator ("LDO" in industry-speak), you still use less power overall. Any efficiencies gained from a switch-mode regulator are over and above that.
I have problems to drive a 2.8 TF via SPI - Page 1
Forum section: electronics / general

author: ale500
author_rank: Frequent Contributor
timestamp: October 17, 2015, 08:17:35 am
content: I have a 2.8" TFT that I bough some years ago. Here is a photo of it. It should have a ILI9341 or similar controller (Maybe a ILI9325, it shouldn't need an A0 line). The thing is I want to drive it via SPI, according to the docu of this controller I need an Address (command/data) line... if I believe the writings on the silkscreen... then I don't need it... On the silkscreen is a "www.powermcu.com" website that at some point may have had such a display in store or so.Any help/ideas would be appreciated !Edit: I forgot the picture :/

author: FreddyVictor
author_rank: Regular Contributor
timestamp: October 17, 2015, 03:44:30 pm
content: all the displays I have have the A0 (or D/C : Data/Command mode) pina quick search gives thissimilar display- appears to be some working code at the bottom of the page which may help ?

author: unitedatoms
author_rank: Frequent Contributor
timestamp: October 17, 2015, 04:40:42 pm
content: This is my SPI TFT blog article. I hope you can find useful bits in my codehttp://www.unitedatoms.com/blog/pixel-herding-with-ili9341-on-quark/

author: obiwanjacobi
author_rank: Super Contributor
timestamp: October 17, 2015, 05:12:26 pm
content: Also sometimes called RS as in Register Select. Look right on the double row header...

author: ale500
author_rank: Frequent Contributor
timestamp: October 18, 2015, 09:26:12 am
content: I saw that pin on the PCB, what is a bit disturbing is the silkscreen legend... oh well, it is then as I thought. I'll try the code for both controllers and see which one works...
picoWiring beta - Page 1
Forum section: electronics / general

author: ralphd
author_rank: Frequent Contributor
timestamp: October 20, 2015, 03:38:50 pm
content: I've just released the first beta of picoWiring - a small Arduino/Wiring library for command-line AVR development.http://nerdralph.blogspot.ca/2015/10/beta-picowiring-arduino-compatible.htmlThe size improvements are significant. piggy-prog, based on ArduinoISP, requires under half the flash (<2K vs 4.5K) when built with picoWiring.
SHARP pocketcomputer PC 1401 manual - Page 1
Forum section: electronics / general

author: Roeland_R
author_rank: Regular Contributor
timestamp: October 17, 2015, 11:21:01 am
content: Hi,Yesterday my "new" pocketcomputer from 1983 arrived. Bought it on the dutch marketpace for only € 18,-. Programming it is not difficult at all, but it would be nice to find an english usermanual pdf. The sites I have found until now do trigger the Virus software to warn me. Does anyone now a safe download?Already found technical specs to connect a cassette recorder for saving and loading programs.

author: HighVoltage
author_rank: Super Contributor
timestamp: October 17, 2015, 12:08:03 pm
content: I have the original manual with my PC1401If you can not find a place to download, let me know and I loan it to you for scanning / copying

author: Balaur
author_rank: Unknown
timestamp: October 17, 2015, 04:28:58 pm
content: I've checked a few files from here, they seems OK:http://pcrus.narod.ru/manualse.htmlA full German one is here:http://www.instructionsmanuals.com/u2/pdf/calculadoras/Sharp-PC1402-de.pdf

author: Roeland_R
author_rank: Regular Contributor
timestamp: October 17, 2015, 06:08:31 pm
content: Thanks Balaur and HighVoltage for your help. The links are great. Kind regards, Roeland.
Atmel Simulator Stimuli creator - Page 1
Forum section: electronics / general

author: Finder
author_rank: Unknown
timestamp: October 16, 2015, 12:36:30 pm
content: Hello, I thought I'd share a some information about atmel studio simulator stimuli files, and a small program I made. Here is alinkto my website. Any feedback will be appreciated.

author: obiwanjacobi
author_rank: Super Contributor
timestamp: October 16, 2015, 05:45:17 pm
content: Register drop down says PINA-PINF - don't you mean PORT?And are the 8 lines in the main screen the 8 PINs?Would be nice to include peripherals like Usart and to be able to use BaudRate instead of having to calc the bit times...I think a numerical entry (table) would be faster for the user.A 'scope' view would be nice to check and correct errors.Also a clear all button.As it stands now its pretty crude - but I think the idea is terrific!PS: the source zip file does not contain all files? (opened with winrar)

author: Finder
author_rank: Unknown
timestamp: October 17, 2015, 01:28:11 pm
content: It says PINA-PINF because on AVR those are the input registers for the processor, and you can change the register to whatever you like.The 8 lines represent the 8 bits of the register (0-7).Other peripherals are in the planning stages once I figure out the best way of doing them.I was thinking of doing a table entry, but decided to do the graphical interface. Though i could do both now that this version works okay.The clear buttonI knew I forgot somethingZIP file should now contain all the files.
best free fixed point digital filter designer - Page 1
Forum section: electronics / general

author: NiHaoMike
author_rank: Super Contributor
timestamp: October 17, 2015, 07:26:53 pm
content: What's the best free software for designing fixed point digital filters? Open source would be a plus, as is native Linux support.

author: Kalvin
author_rank: Super Contributor
timestamp: October 17, 2015, 08:10:11 pm
content: I have used Octave for designing the digital filters, and then I have normalized the coefficients into range +/- 1.0. The I have implemented a simple testbench in plain C running on the PC in order to check that the rounding of the coefficients haven't created any problems.

author: NiHaoMike
author_rank: Super Contributor
timestamp: October 17, 2015, 09:28:00 pm
content: Quote from: blueskull on October 17, 2015, 07:31:33 pmMost likely IIR for low computational requirements.

author: NiHaoMike
author_rank: Super Contributor
timestamp: October 17, 2015, 10:20:25 pm
content: I prefer to learn how to use a free (preferably open source) tool to do it, since learning how to is part of the objective. The application I have in mind is to low pass filter an audio signal (200-1000Hz cutoff frequency, 4 or more poles, preferably adjustable on the fly) in order to drive a linear motor with closed loop control. The DSP I'm using is a dsPIC33F GS.

author: amyk
author_rank: Super Contributor
timestamp: October 17, 2015, 11:58:22 pm
content: A calculator and a brain? At least you don't have to use slide rules...

author: ehughes
author_rank: Frequent Contributor
timestamp: October 18, 2015, 12:25:15 am
content: I have a tool here:https://community.freescale.com/docs/DOC-100240For doing IIR Biquads. You can use the given filter taps and scale to your prefered fixed point format. For higher order, just chain together 2nd order stages.This project (MonkeyJam):https://community.freescale.com/docs/DOC-100149has an example implementation of a fixed point IIR biquad (Q31 format). It uses the SMLAL instruction to give you 64-bit precision in the accumulation of the state variables. This is important is your center frequency is << than you sample rate.The code for Monkey Jam also has a filter designer in the C code to build the filters "on the fly". It is designed to generate coefficients less than 1 (Q31 format) and for filters that implement post scaling. Should be easy to modify for your fixed point format.For IIRs, you need a wa. to atomically update the filter coefficients if you want an "on the fly" The MonkeyJam code has a straightforward way of doing it for reference.

author: AndyC_772
author_rank: Super Contributor
timestamp: October 18, 2015, 07:43:14 am
content: Take a look at:http://iowahills.com/This site has free to use FIR and IIR filter design tools, plus details on the code and methods for designing the filters.
usb microcontroller oscilloscope circuit Query - Page 1
Forum section: electronics / general

author: yalect
author_rank: Regular Contributor
timestamp: October 12, 2015, 06:55:23 pm
content: Hello,I would like to ask you if I can build simple high or medium speed PC/USB oscilloscope based on microcontrollerthank you

author: Howardlong
author_rank: Super Contributor
timestamp: October 12, 2015, 07:09:53 pm
content: There may be other examples, but the LPC4370 LabTool is exactly this used as a demo for the LPC4370. Not high speed, it's 60MSa/s using the MCU's integrated high speed ADC. It's about as good as it gets if you want to use an MCU's own ADC. Beyond that, getting enough bandwidth from an external ADC into an MCU might prove challenging without FIFOs, and then you'd need to think about how to trigger.

author: yalect
author_rank: Regular Contributor
timestamp: October 13, 2015, 07:38:18 pm
content: is there microcontroller oscilloscope project can's works at 50 Mhz ?
programming over SPI with multiple devices - Page 1
Forum section: electronics / general

author: Simon
author_rank: Unknown
timestamp: October 14, 2015, 07:57:24 am
content: I'm going to put an SPI device (ADC) in my system along side my AVR, but my AVR is programmed by SPI, presumably because my ADC needs enabling on the enable pin before it does anything there will be no conflict as the chip will just go high impedance when the AVR is put into programming mode and stops talking to it

author: Mr.B
author_rank: Unknown
timestamp: October 14, 2015, 08:09:55 am
content: I have done this before and not had any problems with it.The "other device" had a pull-up resistor on the CE to ensure it was not enabled while the AVR powered up.

author: mikerj
author_rank: Super Contributor
timestamp: October 14, 2015, 10:41:14 am
content: You should provide a suitable pull-up resistor on the chip select lines of any SPI slave devices, but provided this is in place there should be no problem.

author: Simon
author_rank: Unknown
timestamp: October 14, 2015, 11:58:31 am
content: I'l put a 10K pullup and I've found a free pin to act as the CS line phew how long ago did i start designing this thing ?
AVR parasitic pin capacitance < 10pF - Page 1
Forum section: electronics / general

author: ralphd
author_rank: Frequent Contributor
timestamp: October 13, 2015, 01:19:04 am
content: Not satisfied with the 10pF rule-of-thumb, I decided to measure the parasitic capacitance for AVR IO pins. While 10pF may be a reasonable number for a chip and a trace a couple cm long, the capacitance of a floating pin with no trace is as low as 6pF. Even with an attached trace and header, and plugged into a breadboard, parasitic capacitance is as low as 7pF with a QFN-32 ATmega328p.http://nerdralph.blogspot.ca/2015/10/parasitic-capacitance-of-avr-mcu-pins.html
PIC18 disassembler - Page 1
Forum section: electronics / general

author: Alex
author_rank: Regular Contributor
timestamp: October 10, 2015, 10:54:51 pm
content: Are you aware of a disassembler for the PIC18, PIC18F26K22 to be exact?Alex

author: oPossum
author_rank: Super Contributor
timestamp: October 10, 2015, 11:17:40 pm
content: A list of some disassemblers:http://www.piclist.com/techref/microchip/dissassemblers.htmI used this one a few years ago. Works well.http://www.etc.ugal.ro/cchiculita/software/picdisasm.htmI think there is a way to get MPLAB to do a dissembly, but I don't remember how.

author: Alex
author_rank: Regular Contributor
timestamp: October 11, 2015, 12:17:11 am
content: Thanks oPossum - I have in the meanwhile done a disassembly via MPLABX. You load the hex file as a prebuilt source to a new project. You then go to Window->PIC memory views->Program memory. You can also run the code in debug mode with the simulator and see for example what is written in SFRs.I have downloaded the picdisasm and done a disassembly. Looks robust and matches the MPLABX disassembly - at least the part I am interested in.Alex
STM32F4 and a 25Q128 (128MBit spi memory) - Page 1
Forum section: electronics / general

author: Monostable
author_rank: Contributor
timestamp: October 13, 2015, 09:51:03 am
content: Hello allI am currently trying to add some memory to on of my project (using a STM32F4 Discovery), to do so, I ordered three 25Q128A, I printed three small adapter (seepictures 1).I configured the SPI1 of the STM32F4 on the pins PA 5 6 7, and pin as an output to serve as CS (PE7), I placed the Pull-up / Pull Down resistor on the SClock and the CS as it was specified in the data-sheet.The schematics are onpicture 2.I tried to read the manufacturer ID, and it just send back incoherent data (p36 of the data-sheet specify that it should output 0x20 and it just output whatever it wants).Same goes for the Status Register.As for the writting / reading it is even more random, I don't think I'm able to write in the memory.At first I though it could be a cable disconnected or misplaced, so I got my oscilloscope and checked the signals (picture 3), and everything seems to be fine.I tried on the three chips, so I guess the problem comes from meI also included a link to theDATASHEETI use (there are two different but with similar content available on the internet)I am starting to run out of things to try to make this chip work with my micro-controller, would you have any hint ?

author: helius
author_rank: Super Contributor
timestamp: October 13, 2015, 09:59:21 am
content: How are you reading the SPI? The in and out bits are sent synchronously at the same time, so the MCU needs to send a byte of data to receive the response from the memory chip, after it has sent the command.

author: Monostable
author_rank: Contributor
timestamp: October 13, 2015, 10:02:05 am
content: Quote from: helius on October 13, 2015, 09:59:21 amI first send the command and then send a dummy byte, (as in picture 3, on this one the memory reply a simple 0x00)

author: mikerj
author_rank: Super Contributor
timestamp: October 13, 2015, 10:33:26 am
content: Have you configured the STM32 to use the correct SPI mode for the 25Q128 (clock phase and polarity)?

author: Brutte
author_rank: Frequent Contributor
timestamp: October 13, 2015, 10:43:52 am
content: Why the MOSI is so tiny wrt other?

author: Scrts
author_rank: Frequent Contributor
timestamp: October 13, 2015, 01:27:29 pm
content: Also chip select is set to high in the middle of the last clock cycle. It might push the SPI peripheral out of sync and it might be messy on the next transfer.

author: Monostable
author_rank: Contributor
timestamp: October 13, 2015, 02:02:39 pm
content: Quote from: mikerj on October 13, 2015, 10:33:26 amThank you so much! that was the problem !I can't belive I overlooked that part ....I feel so embarassed now.Quote from: Brutte on October 13, 2015, 10:43:52 amThe calibre is different, and I didn't bother changing itQuote from: Scrts on October 13, 2015, 01:27:29 pmI have checked with cursor, and the CS goes high right after the last clock tick. (yellow signal)
Any PSoC4/5 experts out there? - Page 1
Forum section: electronics / general

author: rwgast_lowlevellogicdesin
author_rank: Frequent Contributor
timestamp: October 10, 2015, 02:21:35 am
content: Ive been playing with the PSoC chips for a while, there pretty neat seeing as how you get a handfull of parts in 1 chip less than 5 dollars, granted most of these parts are pretty jellybean but sometimes thats all you needAnyways lately I have started to realize that an FPGA or maybe a CPLD is a better route for a few projects I want to do. I dont know much about them and they kind of scare me lol. Ive heard things like it takes close to 5 years to actually get good with them, that is doing more than building some glue logic or peripherals...I know there are alot of FPGA newb kits out there... but I was wondering if learning to build digital block in an HDL would get me off to a good start. I already own cypress stuff, I know how to use the IDE.. and from what I remember reading it is possible to build your own logic block in an HDL. But how will that translate to an altera/xilinx/lattice product? After using an HDL for PSoC will I be able to pick up on the bigger names and my only learning curve will be the IDE?I was also wondering if there was a way to build custom analog blocks? If there is I would guess they are made in spice?

author: miguelvp
author_rank: Super Contributor
timestamp: October 10, 2015, 02:38:27 am
content: Did you try modifying their components? that will give you access to the Verilog code if they used any for that component.

author: rwgast_lowlevellogicdesin
author_rank: Frequent Contributor
timestamp: October 10, 2015, 12:49:56 pm
content: Hmmm, so you could be an HDL guru, and still have a huge learning cure with there IDEs? Which vendor has the most friendly? Which chips do analog synth, there affodable and work with the free tools? Secondly i have heard VHDL is more of the industry standard and is safer to use along with getting you away from a C syntax?
FPGA and FT232H. Difference between, simulation, logic analyser and text file. - Page 1
Forum section: electronics / general

author: Boscoe
author_rank: Frequent Contributor
timestamp: October 06, 2015, 04:58:34 pm
content: Hi,Just need a little help with my project. It consists of an FPGA and a FT232H that is used in a data logger type fashion. On average data will be transferred at 5MB/s but I'm using the FT232H in 245 sync mode so I have written some hardware FIFOs to buffer my continuous data stream. I am having some trouble with it all though.In Modelsim everything works fine but I'm not using any libraries for my Cyclone IV FPGA so I may have some issues there.On my logic analyser everything is almost there apart from receiving an extra clock cycle after 'wr' goes low. The data on the bus also starts off differently than in the sim.Then in my console program I get weird results too. I'm sending just 2048 bytes over the bus at one time however I often get a random number of bytes being received, anything from 2040 to 2055. When I start trying to receive more than one packet (2048 bytes) I start loosing a large amount of data (almost half). Also the values I receive do not correlate with what I see on the logic analyser. For instance in my program the data should start at 0 and increment to 255 and then reset and continue. However, what I actually get is 255 to start (which is not on the bus!!) then 0 and continues normally. It then ends up with a 0, both of these values make sense for the sequence but they shouldn't be there as they are two extra bytes that aren't sent from the FPGA.I'm not sure what to believe. The logic analyser seems like the most reliable source of info.Any help or advice would be helpful!Thanks

author: ale500
author_rank: Frequent Contributor
timestamp: October 07, 2015, 05:17:00 am
content: It looks like as if the '232 is not sampling the data correctly, either due to frequency mismatch or due to sample/hold time violations.You may want to debug that link first. A simple state machine could be used to send data to the '232, it may sound silly but I'll go the extra step to be sure that you are driving all signals timely.

author: electro-logic
author_rank: Contributor
timestamp: October 07, 2015, 06:05:01 am
content: Hello,I've written some articles about FPGA and FT232H, see my blog athttp://electro-logic.blogspot.comJust use Google TranslateYou have to add timing constraints and sample txe also on falling edge to make ft232h worksLeonardo

author: Boscoe
author_rank: Frequent Contributor
timestamp: October 09, 2015, 06:35:31 pm
content: Thanks guys. I've had a read through your blog and it's interesting. I've nearly solved my issue in general but I just need to make 'wr' go high one clock cycle before i currently have it. I'm getting an extra 0 on the end of my stream. Other than that I sometimes get (randomly) 2052 received and always 2052, it's the normal data stream just with four '0's on the end which i find strange.
The GNU ARM Eclipse project has a new look and a new home at GitHub - Page 1
Forum section: electronics / general

author: ilg
author_rank: Newbie
timestamp: October 06, 2015, 08:41:44 am
content: OverviewThe [GNU ARM Eclipse project](https://github.com/gnuarmeclipse) includesa set of open source Eclipse plug-ins and tools tocreate/build/debug/manage ARM (32-bit) and AArch64 (64-bit) applicationsand static/shared libraries, using the latest GNU ARM GCC toolchains.New lookStarting with September 2015, the [GNU ARM Eclipseweb](http://gnuarmeclipse.github.io/) site has a completely new look.(see attached github-io-gae-home.jpg)Apart from the aspect (definitely cool!), the main functional change isthe addition of the right sidebar, to facilitate access to the projectdocumentation.The new site no longer uses WordPress; instead, it is entirely staticand was generated with Jekyll.New project home on GitHubWith GitHub gaining more and more traction, the GNU ARM Eclipse projectwas migrated from SourceForge to GitHub.RepositoriesThe migration of repositories was easy, each project was pushed into itsown repository.The current project repositories are:plug-inswindows-build-toolsopenocdqemubuild-scriptsBinary files as ReleasesThe migration of binary files was a bit more complicated, and, due tocurrent GitHub limitations, is incomplete. The main problem was raisedby the two Eclipse update sites, which require a certain folderstructure, and since GitHub currently does not support adding folders toreleases, the Eclipse update sites will remain hosted on SourceForge (athttp://gnuarmeclipse.sourceforge.net/updates).Except the Eclipse update sites, all future binary files will bepublished as GitHub Releases, attached to the respective projectrepositories.The archive of past releases was also migrated from SourceForge toGitHub.Issues trackersThe SourceForge trackers were replaced by the GitHub Issues trackers,one for each project.It is planned to preserve the content of the old SourceForge trackers,even if now they are locked and new tickets cannot be created there.Notifications via watched projectsFor those interested in receiving notifications, the recommended way isto subscribe to the GitHub projects, by clicking the Watch button andselecting Watching).In addition to the gnuarmeclipse/plug-ins project, it is alsorecommended to subscribe to the gnuarmeclipse/gnuarmeclipse.github.ioproject, to receive notifications for new Web posts.More infoFor more details about the GNU ARM Eclipse project, please refer to theproject sitehttp://gnuarmeclipse.github.io/.

author: Bassman59
author_rank: Super Contributor
timestamp: October 06, 2015, 04:51:15 pm
content: Thanks for the update!Your project is GREAT.-a

author: ralphd
author_rank: Frequent Contributor
timestamp: October 08, 2015, 04:50:20 am
content: From the description its not clear if it actually includes gcc.

author: aon
author_rank: Contributor
timestamp: October 08, 2015, 07:36:48 am
content: Quote from: ralphd on October 08, 2015, 04:50:20 amIt doesn't - the installation documentation has a chapter on getting the toolchain.
Which TI Arm CPU for 1080p video camera? - Page 1
Forum section: electronics / general

author: davorin
author_rank: Unknown
timestamp: October 06, 2015, 05:01:27 pm
content: Evnin'TI has a nice IP camera reference guide which should help to choose the right CPU for specific resolution/framerate needs...For example the DM368 would be enough for 1080P@30fps, also TI marks this device as active...but oddly the video evaluation module is labelled at their site as "NRND" (not recommended for new designs).So which TI CPU would be best for hooking up a camera to record video at this resolution?

author: lukier
author_rank: Unknown
timestamp: October 06, 2015, 05:13:30 pm
content: DM368 is quite popular in IP-CCTV cameras it seems.Search for DM368 on Aliexpress and plenty CCTV cameras, from full devices to board modules pop up, often quite cheap.It is not a very modern part, hence probably the low price and popularity on Aliexpress. Another similar old cheap chip is Hi3516/Hi3518 from Hisilicon.The thing is that it is almost impossible to do any serious processing, these CPUs are simply too slow, so the video stream is more or less a fixed pipeline. There is a sensor interfacing block (parallel pixel bus), then image signal processor that controls the sensor (exposure, gain etc) and hardware H264 encoder block and that's pretty much it. That's why they get away with 100 Mbit Ethernet on these boards.I have a couple of Hi3516 camera modules that I'm planning to experiment on. On the internet there is leaked SDK and datasheet for the chip, it is running u-boot and 3.0 linux kernel. The drivers for the hardware accelerated blocks are closed source binary blobs.If you only need recording that might be a viable option, provided the bitrate will be low enough for built-in Ethernet/USB host/SD card controllers.

author: rsjsouza
author_rank: Super Contributor
timestamp: October 06, 2015, 07:10:22 pm
content: Quote from: davorin on October 06, 2015, 05:01:27 pmIMHO the DM368 is a good part - there is a lot of video encoding/processing done by coprocessors, which relieve the main ARM9 processor from the heavy lifting (in the past I used its less-powerful siblings DM355/DM365).The dev kit being NRND is odd, but perhaps it is only the complete breakout board that is in this stage. I recall a company called Appro and itsIPNC kitseems it is still in production.TI has other video processors based on Cortex A8 such as DM385 and DM388, but I never worked with them. I am pretty sure they have more processing power, but double check if they have a stable software devkit (SDK) for them.
another poorly-designed cheap Chinese AVR board - Page 1
Forum section: electronics / general

author: ralphd
author_rank: Frequent Contributor
timestamp: September 29, 2015, 11:22:38 pm
content: I recently bought a 268c UNO compatible board. While some things are nice like the extra holes for breakout pins, whoever designed the board didn't know that SMD ceramic resonators shouldn't have external loading caps. I've seen Chinese boards *without* parts populated that should be there, but this is the first time I've seen one with parts that shouldn't be there.http://nerdralph.blogspot.ca/2015/09/under-3-chinese-arduino-uno-compatible.htmlWhile removing the caps got the clock frequency within +- 0.5%, I think I'll also try changing the clock fuse settings to full swing instead of low power to see if it makes more of an improvement.

author: amyk
author_rank: Super Contributor
timestamp: September 30, 2015, 12:38:41 am
content: They decided to go with cheaper resonators instead of crystals and forgot to remove the caps? Also, not all resonators have built-in loading caps.

author: ralphd
author_rank: Frequent Contributor
timestamp: September 30, 2015, 01:45:10 am
content: Quote from: amyk on September 30, 2015, 12:38:41 amThe resonators often aren't any cheaper than hc49 crystal oscillators. The SMD resonator has 3 pads, like the ones with loading caps. The timing improvement from removing the caps also indicates the resonator has internal caps.

author: westfw
author_rank: Super Contributor
timestamp: October 01, 2015, 09:56:05 am
content: I find it ... philosophically interesting ... that these boards HAVE beendesigned(even if poorly.) The stereotype and expectation for the cheap boards is that they'll all be copies of some (probably reasonable) design from somewhere else. And yet, we see boards with no bypass caps, boards with extra crystal caps on a resonator, boards with no input/output caps on the regulator, a variety of usb/serial converter chips/circuits, a variety of extra connector footprints, and so on. In a way, it's very encouraging...

author: ralphd
author_rank: Frequent Contributor
timestamp: October 01, 2015, 11:03:44 am
content: Quote from: westfw on October 01, 2015, 09:56:05 amAgreed. I think it proves what a drama queen Banzi is with his attack of the clones hype.

author: richardman
author_rank: Frequent Contributor
timestamp: October 05, 2015, 08:19:07 am
content: Quote from: westfw on October 01, 2015, 09:56:05 amSo you are saying that it's like the test for bridge loading: you build a robust bridge, and then start removing stones until it falls down. Then you rebuild with the last stone un-removed?
New Complete Hardware+Software Kit for C Cortex-M Programming - Page 1
Forum section: electronics / general

author: richardman
author_rank: Frequent Contributor
timestamp: October 05, 2015, 06:13:22 am
content: // EDITED: Content posted to buy/sell/wanted subforum. Sorry for the trouble. One thing I should leave here is that we have implemented "JumpStart API" which is an abstraction layer that is higher level than (most) OEM HAL, for example, I2C objects on top of I2C_WIRE object, but still does not prevent you from accessing the full power of the chips, for example, unlike mbed and Arduino. ALso that we are offering complementary kits to bloggers etc. please see the proper post for details.

author: Karel
author_rank: Super Contributor
timestamp: October 05, 2015, 06:36:46 am
content: Quote from: richardman on October 05, 2015, 06:13:22 amThere is a reason there's a separate thread for it:https://www.eevblog.com/forum/buysellwanted/

author: richardman
author_rank: Frequent Contributor
timestamp: October 05, 2015, 08:05:36 am
content: Thank you Karel. I will move / copy-delete this.