Post-Processing

General discussion for dsp.stackexchange.com
14:16
@PulasthiUdugamasooriya We haven't given up on it.
Thu 17:17
Folks,
Does anyone have favorite references about software NCO (numerically controlled oscillators) ?
For a sense of scale, it would run in an Arm Cortex-M4 microcontroller, and generate frequencies between 10 and 20 kHz.
 

 The Skunk Works

To the optimist, the glass is half full. To the pessimist, the...
Fri 14:55
 

 Electrical Engineering

A place to talk with friends from the EE community about vacuu...
Thu 19:42
Yes, I mean DDS. The pure digital part of the DDS before the DAC.
Thu 19:41
What do you think about this NCO algorithm: zipcpu.com/dsp/2017/12/09/nco.html, or hesliplabs.com/blog/nco (same algorithm) ?
Thu 19:39
@tobalt I'm trying the LUT with interpolation at the moment.
Thu 17:18
Folks,
Does anyone have favorite references about software NCO (numerically controlled oscillators) ?
For a sense of scale, it would run in an Arm Cortex-M4 microcontroller, and generate frequencies between 10 and 20 kHz.
Thu 00:21
This is not a 6-terminal resistor, really. It's a 4-terminal where the sense lines expressly pick up in the middle of the high current trace.
Wed 00:43
I only have to write the bring-up code to test the hardware. Firmware at large is others’ task.
Wed 00:42
Folks,
I’ll have to write a limited amount of bring-up code for a SAM D51 microcontroller. What IDE would you recommend these days: Atmel Studio (Microchip Studio) or MPLAB ?
Jul 21 15:36
@Gr_10 Don't know what the recommendation is for hosting non-picture files. It may be a question for the EE.SE meta-board . I asked in the meta.SE chat, and the response was that it may be stack-specific.
Jul 17 16:17
@tobalt It will be a while before I resume posting answers on SE [don't know if SE will be around that long]. Chats still okay.
Jul 17 15:51
In addition to Lundin, you'll get Olin. (Nick too, fwiw.)
Jul 17 15:50
@tobalt Inviting you to mirror your question on EE.Codidact too. electrical.codidact.com
Jul 15 14:28
It might attack copper which is dangerous, come to think if it. Copper (transitional metals in general) catalyze decomposition of hydrogen peroxide. That’s how it will blow up in one’s face.
Jul 15 13:58
@tobalt Shops which wind motors, transformers, inductors could do a magnet wire cut&strip job for you. They should be equipped for processing magnet wire, I imagine.
Jul 15 13:55
Chemical stripping of magnet wire is a known technique. It's probably done with something milder than Piranha.
Jul 15 13:50
@rdtsc Oh one can. Piranha solution is a mix of concentrated sulfuric acid and hydrogen peroxide. It oxidizes most organic compounds. Piranha requires more precautions than aqua regia, arguably.
Jul 14 04:45
I was only able to find distributors of Keller’s more integrated sensors with pipe threads.
Jul 14 04:45
Jul 14 04:43
Folks, does anyone know who is the distributor for these Keller Pressure sensors ?
Jul 11 01:49
@tobalt How many sensor nodes? What are the distances?
Jul 10 21:52
Modbus over RS-485 is still alive, although may be too slow for 16 bit 10ksps.
Jul 10 21:49
@Lundin ... EtherCAT too, but the nodes consume a lot of power.
Jul 10 14:51
@tobalt That’s impossible on the fundamental level. The more informed one is – the more regrets he has, and hates himself. ; )
Jul 10 14:51
> ... And I am wondering whether it's possible to make an informed choice of a field bus without regrets and without hating my life lol
Jul 10 14:18
To make things a little more abstract and harder to look up, many MCUs have universal hardware which implements SPI, I2C, UART depending in configuration in firmware. It’s called different names in different MCU families. Atmel SAM D51 calls it SERCOM, Infineon calls it USIC, Texas Instruments calls it eUSCI.
Jul 10 14:18
@tobalt I/O pins on MCUs have a pin function mux. The SPI hardware can be one of the function sometimes. The specialized SPI pins on MCUs can be connected to a dedicated SPI hardware in the MCU which handles SPI transactions in hardware. It allows faster SPI, or less power consumption.
Jul 10 13:37
I2C and SMBus devices have fewer communication bus surprises.
Jul 10 13:36
There are plenty of devices which comply with core SPI spec, too.
Jul 10 13:36
Joking mainly, but I had to create tweaked SPI implementations on the MCUs too. AD7714 comes to mind with its DOUT/RDY# . Analog Devices is [or was?] a leader in SPI spec abuse.
Jul 10 13:25
@rdtsc SPI is more of a tradition, than a specification.
Jul 8 17:25
Speaking of PCBA shops. I'm having a dickens of a time with CircuitHub. (I have to use them for work.) I don't recommend them.
Jul 8 14:05
PCBAs without borders (give or take tariffs).
Jul 8 14:05
@Lundin I’m open to working with a PCBA shop in Poland, Slovenia, the Balts, Icelanders, Mexico, Argentina. Do they have PCBA shops with intake portals like JLC, or Sierra, or Tempo Automation?
Jul 8 13:59
@Lundin So far I’ve placed two PCBA orders with JLC in China. Nothing special about board complexity. Both have worked out. The first one was a prototype for work (qty of 50). The second one was a hobby production run (qty 10).
Jul 7 19:08
They have their own parts stockpile too. If you can use the parts from the JLC's stockpile, then the parts procurement time is shorter.
Jul 7 19:08
@VoltageSpike A month ago (in China) had put together 10 boards for me. PCB fab, assembly, shipping of final product took under 2 weeks. JLC procuring parts from DigiKey took about 2 weeks.
Jul 7 16:12
Does the assembly shop have to be in the US? Or in the Free World? Or can it be anywhere?
What kinds of quantities? What kind of lead time?
Is it for prototyping or for production?
Jul 7 16:11
@VoltageSpike Heh. Dealing with the same question as we speak.
Jul 6 20:57
Is any one using an IPC-2581 viewer? If you do then which one? ipc2581.com/free-viewer
Jul 6 00:23
@tobalt We had BNC cables hanging on the wall of the EE lab. They slithered into the pre-production unit which eventually went to the EMC scan. [You can guess the ending.] The cables were junk from Amazon, as it turned out. The shields were connected by about 20mm of drain wire. We had to go to the EMC chamber the second time.
 

 Photography Chat

All-things photography related discussion.
Jul 15 14:59
Jul 15 14:59
from this answer about rolling shutter
 

 The Hangar

General discussion about aviation.stackexchange.com The white ...
Jul 15 03:39
video about airliner avionics cooling
Jul 11 14:15
 

 English Language & Usage: Multi-Layer

Not for the faint of heart or those easily triggered by Englis...
Jul 8 15:17
Folks, what's the proper use of w/ w/o w/no abbreviations ?
Are they a local to GB or US or NATO, or are they generally understood by the English speakers?
Jul 7 16:40
Why would Investopedia have an article about Bill of Mtaerials?.. investopedia.com/terms/b/bill-of-materials.asp