Recent Posts

1

Power/Renewable Energy/EV's / Re: Why are all Vicor PI3 modules suddenly out of stock or obsolete?

« Last post by Faringdon on Today at 11:34:34 am »

You have contacted your local Apps Guy from VicorPower?.
I find with Vicor you need to do that.

2

Microcontrollers / Re: Has anyone used ASAN & MSAN, and relevance to embedded arm32

« Last post by peter-h on Today at 11:33:42 am »

Yes; those help with a) using the FreeRTOS internal heap (which I don't use) and b) overrun of the task stack due to e.g. some function which has big local variables.

The problem with using those checks is that they only tell you if the thing has blown up. One needs a separate tool to check if there is enough margin. I got a graphical tool developed on freelancer.com which shows the 64k RTOS stack area and it shows the unused stack space etc. Anyway that's a bit off topic

3

FPGA / Re: Analog video output with FPGA ?

« Last post by langwadt on Today at 11:26:24 am »

If you want 8 bits per channel, look for the cheapest RGB video DACs and be done with it.  I know it's overkill, at these thing can run at +200Mhz, but it's easy and regulated outputs, with 75ohm cable driver built in with static immune outputs.

Try this guy:

ADV7125xxxxxx are still available at $7 to $9 USD a piece.  (search for alternate suffix as the 330MHz version I listed may be overkill)

ADV7123xxxxx are available at $5.37 USD, but you will need to buy 10 of them.  These are the cheapest if you go to ~25 pieces at they drop to $4.40 USD.

you can also get a clone of the ADV7123, for ~$2

https://www.lcsc.com/product-detail/Digital-To-Analog-Converters-DACs_HTCSEMI-HT7123ARQZ_C2886392.html

4

Projects, Designs, and Technical Stuff / Re: Accurate sine wave in terms of amplitude

« Last post by sw_guy on Today at 11:19:16 am »

>What is the target distortion ?
I do not know yet.

One option is that: do not care. I can measure what the amplitude is and then do the math one way or another.

5

Repair / LED Strip lights flashing like a bad 90s rave

« Last post by Grytpype on Today at 11:18:29 am »

Hi All, Hope you're all well!

My LED strip lighting just decided to crap out and now, very consistently, strobe as per the attached gif.

The components inside the power supply all look fairly straight-forward to me bar the SMD led driver (BP3319MB) on the bottom-side of the PCB.

I swapped out the SIF10N65C mosfet in a straw-clutching moment with a near-as-damn-it equivalent but the disco continues. The caps all measure ok and I can't see anything else obvious.

Anyone have any experience / ideas on what this could be? They're not expensive to replace but feels like this could be something fixable.

Thanks in advance!

6

Test Equipment / Re: Choosing between entry-level 12-bit DSOs

« Last post by gf on Today at 10:56:19 am »

Can the TSA do amplitude modulation?
Put in some AM at about 10% of the frequency.

It only supports a limited number of amplitude levels (I think 8 or so) for the the modulating signal, so it's a "stair step sine wave".
And the modulating signal is limited to 10 kHz.

7

Projects, Designs, and Technical Stuff / Re: Corrosion on DIP pins

« Last post by rsjsouza on Today at 10:50:35 am »

Assuming there was no ingress of any kind, as mentioned before the manufacturing of the computer might have either scratches some parts or left residue that slowly corroded over the decades. I have seen many boards like that.

One additional point is that there were crap and good leadframes as well especially from that era (1970s-1980s), even with parts from the same manufacturer but different lots or country of origin. Standards for handing and storage of ICs were still being developed.

Just an additional annoyance: MOSTEK is known nowadays to have a relatively high incidence of memory rot, which renders the IC unusable due to internal degradation even on ICs that are physically in good shape.

Good luck in your repair/restoration!

8

Embedded Computing / Re: Is it possible to read AHCI registers using setpci on Linux?

« Last post by magic on Today at 10:46:48 am »

AFAIK setpci only access the configuration address space of PCI. If the registers you are looking for are there then you are set. If they are in some MMIO region, I don't see a way of reading them with setpci.

However, the related lspci (with -v flag) will tell you where the MMIO registers are mapped in the CPU physical address space. Knowing this, you could presumably read them by means of /dev/mem or something like that (note: in recent times there were some attempts to restrict or completely remove this mechanism on security grounds and I'm not sure how it works in mainstream distributions these days).

9

Beginners / Re: Comparator circuit seems to be oscillating (well, pulsing, really). Solutions?

« Last post by Tandogan on Today at 10:35:38 am »

Hi

I need your help.

I have checked the capacitors on my digital piano and got the following results in ESR levels. I used the peak ATLAS ESR70 gold.

10000 uF 25V - ESR 0.01
2200 uF 25V - ESR 0.02
470 uF 10V - ESR 0.20
100 uF 25V - ESR 0.43
47 uF 16V - ESR 0.64
10 uF 16V - ESR 1.01
1 uF 50V - ESR 1.10

I am especially suspicious about ther results for 10 micro and 1 micro F. They should be around 8 and 5 respectively. Do these results mean that I need to change the 10 micro and 1 micro D capacitors?

Thanks for your replies.
Tan

10

Mechanical & Automation Engineering / Repurposing PVC Pipe for DIY Projects

« Last post by jonovid on Today at 10:28:37 am »

looks like a good Idea for one of a kind electronics enclosures , modified power tools or battery box's

what type of PVC glue would you recommend for this? as it must melt the PVC laminate sheets into one solid block without delamination over time .