Recent Posts

Pages: [1] 2 3 4 5 6 ... 10 Next
1
Microcontrollers & FPGAs / Caught wind of a new STM32 series...
« Last post by technix on Today at 03:20:02 am »
The local ST authorized reseller called me in for a meeting, and I caught wind of something: a new line of STM32 called STM32A7 series. It does seem to me as if this line of chips would have Cortex-A7 cores, together with STM32F7/H7 as ST's way to one-up i.MXRT series and maybe even encroach into the low end i.MX6ULL market.

p.s. I wish they would have a low cost dual-core STM32A7 on this roadmap, which would compete with even Zynq 7010. Currently the cheapest dual core Cortex-A chip with open documents from a world-class reputable brand (this eliminates Allwinner, MediaTek, Rockchip etc which does not provide open documents themselves. Allwinner does have open documents available but that is a community effort not affiliated or even supported by Allwinner) on Taobao is XC7Z010 - AFAIK AntMiner used that chip for its sheer cheapness for a dual core name-brand ARM chip, and just let the FPGA side go to waste.
2
Beryllium Oxide "thermal links" were used on conduction cooled vacuum tubes, where the anode may be operating at thousands of volts above ground.

3
Repair / Re: Agilent DSO 6034A [Bootloop]
« Last post by Carrington on Today at 03:19:45 am »
EEPROM? AMD chip?
Can you post a picture?

Have you tried to recover it via usb?
https://www.keysight.com/main/editorial.jspx?cc=ES&lc=eng&ckey=670496&id=670496
4

On Electronica fairs Rigol showed also MSO8000 series scope. I remember it looks similar to MSO7000 except it is black like MSO5000. It has 10GS/s and 500M memory but I don't remember the bandwidth options. It is probably the same hardware as MSO7000 but for higher bandwidths. Unfortunately I don't have photos of it but I've found one picture on the net:

8000 has 1 and 2 GHz bandwidth, also software unlockable.  I'm not sure, but it probably has 2 ADC, so sample rate doesn't drop to less than 5GS/sec per ch. That needs to be verified though.
They also said they are going to release soon new series that will go to 4GHz with 20GS/sec converters.  It seems their chipset is still being refined on a  hardware level.

5000, 7000, 8000 all have IDENTICAL software, trigger, decode and measurement capabilities. They handle measurements very fast, but UI is very laggy at the moment. Dragging things on a screen with a finger is a guessing game.. Although much fancier R&S 3000 series is just a bit faster, but not much, so they are not the only ones with that problem.

Rigol new series hardware seems solid and with plenty raw power. Software platform needs more work, both in optimization of UI speed, and in functions. It has 4 math channels but hey are on the same level of complexity as DS1000Z series.  But as I said, they seem to be in active development of platform, so they will be adding capabilities. They might add advanced math pack later and such.
That remains to be seen.

Regards,
5
Repair / Re: HP 5340A Frequency Counter Resurrection
« Last post by TERRA Operative on Today at 03:17:51 am »
So I got a little bored and poked around where I shouldn't. :D
A good excuse to crack out the Amscope and see what's happening at the Ant Man level.

I had a look inside the Pre Amp Assembly #1 to check that nothing was obviously burnt out.
It all looks good for a visual inspection, and the transistors are still available too if needed, the larger metal can can be got NOS for a not completely unreasonable price, and the two smaller cans (2N5179) are available from Digikey, so that's good.

However, if the other two bits pictured in closeup are bad, it'll be up to what I can salvage from another unit. Fingers crossed they are ok...
6
Hello, i am locking for phasenoise infos about  gpsdo's from ebay  - allan deviation and 10.xxx  mhz is often / always shown in net - but phase noise, i missed.
NEC Star4+ and and - find nothing.
Can someone show phase noiseplots ?

greetings
7
Quote
Get the timing and factor squared away for proportional before even considering integral or derivative.
Excuse me but I don't understand what you are saying here. What's the timing? You mean to change the sampling period?

Quote
Here is a pretty good article about PID but Google is FULL of similar documents.  I like this one because I have Matlab and as soon as I get it printed, I'm going to play with it.

you probably forgot the link.

Quote
it'd think it should be, output += (error * KP) + ((prevError-error) * KD)

You probably are right. I'll double check it.
8
General Chat / Re: Gnu/Linux Considered Harmful
« Last post by tooki on Today at 03:16:32 am »
Well, you can move apps onto a disk on a Mac, fundamentally. Some applications don’t like this at all, but most are just fine with it. However, they do normally look for preferences, etc in the user’s home directory, not on the external disk.

There’s literally no difference in this regard between Mac OS X and classic Mac OS: both have a Preferences folder, and in both, an application on an external disk still looks for the preferences file in the Preferences folder. (It’s been a long, LONG time since Mac applications kept their preference files in the same folder as the application file!!!) Same with dynamic libraries and other assets in the Application Support folders. (Many assets will also work if simply located in the same folder as the application file. This is a way of e.g. providing a library without having to put it in the System folder.)

Some applications are smart, and will launch with the preferences file in an arbitrary location by dragging the preferences file onto the application icon.
9
The type of a pointer is of what it points to, rather than the pointer itself.

char usually represents 8-bit data which can be signed or unsigned depending on other keywords.

A compiler can treat char (without other keywords) as either signed or unsigned by default, which somebody chose to suit the environment.

The compiler for the first example must have char as unsigned by default, the second compiler has char as signed by default. It should be possible to change the default with compiler parameters, but you want to avoid doing that unless you want to recompile system libraries and have a non-standard environment.

Assuming you have a reason for your data to be unsigned char, the simplest way is to cast the type of your pointer to match the strcpy parameter type.

strcpy( (char *) bp, "Hellow");

Note that casting pointers is a normal thing to do but it is a blunt weapon that you should take care using.
10
Dodgy Technology / Re: Amazon Prime
« Last post by SiliconWizard on Today at 03:13:30 am »
In fact, before Amazon started pushing Prime in Germany, their regular shipments arrived within 1 or 2 days. Once they started to emphasize Prime, it feels like their regular shipping has slowed down, by at least a day on average.

I noticed that as well.
Pages: [1] 2 3 4 5 6 ... 10 Next