Re: "Analogue" indication on Oled display
On Tue, Sep 13, 2022 at 08:36 AM, Harvey White wrote:
I've done some display work, and I generally find that the Arduino (at least the MEGA series) is too slow and has too little memory to be useful for involved graphics.? However, there's a U8xxxx library out there that seems to be a standard for arduino projects.? I've transitioned to the STM32 series a while ago.
I would add, for those that don't know, the Arduino ecosystem is oriented towards being relatively easy and educational and such. But when performance is important, it's better to use the MCU chips "more directly", meaning (typically) code written in C, using the vendor's development GUI (they all tend to be similar), and taking advantage of the vendor's own driver libraries.? Note that for nearly all applications, any of the major MCU vendors can get the job done. They have dozens of chips, a bunch of Eval Boards, code libraries, tutorials, etc. I think that the STM32 series is good, but I've never used it. Over the years I've implemented many dozens of apps for MCUs (in my 'real job' and as a hobby), for a long time using Microchip parts, then in more recent years T.I. Now retired, I still do a lot of hobby projects using T.I. Tiva, MSP430, and MSP432 -series parts. Any more, I always use an Eval board as the basis of the HW. Most of the boards are less than US$20, have an on-board USB programmer, have a bunch of 0.1" pins to connect to, and sometimes other useful parts. I've made custom PCBs in the past, but it no longer feels like a good investment of my time. Pete
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Tektronix scope bandwidth?
Way back about 1970 I was told that
Tektronix rated their scope bandwidths at +/- 1 dB.?
?
Question?? Is that true and if so, do they
still do that?
?
Paul, W8AEF
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Re: "Analogue" indication on Oled display
On Amazon, I think I've seen a transparent LCD capable of
graphics, somewhere in the 20 to 30 USD range.? Putting a meter
behind that might work.
Harvey
On 9/13/2022 4:38 AM, Michael Kellett
wrote:
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Is the R &S actually a moving coil meter with an LCD scale -
that's very nice but expensive to replicate !
MK
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Re: "Analogue" indication on Oled display
I've done some display work, and I generally find that the
Arduino (at least the MEGA series) is too slow and has too little
memory to be useful for involved graphics.? However, there's a
U8xxxx library out there that seems to be a standard for arduino
projects.? I've transitioned to the STM32 series a while ago.?
While I do have some code, I haven't tried real-time graphics
with it.? It's built for flexibility and versatility.? It takes
display packets (can manage remote displays), decodes them, calls
graphics primitives, and then writes to a 32 bit display image.?
That writing can be directly to the display hardware or a buffer.?
(for some chips, you need the buffer because of display pixel
mapping).? A background task can take an update packet on a queue
to refresh the actual image on the display.
Currently, it runs the SSD1306/SSH1106 OLED displays, the ILI9341
320 * 240 TFT displays, and should be able to run S1D13517 and
S1D13781 EPSON graphics chips.?
Lots of built in primitives, multiple fonts, graphics, character
graphics/icons, etc.
What may be of use to you is the basic TFT routine (common to all
displays) and the individual chip drivers.? Currently, I have
versions that run on AZURE and FreeRTOS.?
You could either hardware design a specific board or design a
daughter board for one of the Nucleo boards.? I have suggestions.?
Harvey
On 9/13/2022 8:40 AM, David Holland
wrote:
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I've been attacking it this-a-ways....?
?(Screenshot is from my linux/SDL "port")?
There's some other (older) examples?here:?
(Yes, I've been piddling?with it for a long while....)
I've got too many old meters that have multiple differing
scales upon them, depending on what functions are selected,
for a single scale replacement to be entirely satisfactory.
(I'm looking at you, assorted tube testers &
VTVMs...)? ??
While most of my meters still work, I thought it'd be
nice to have a relatively functional drop in replacement.
I'm intending to use an AMC3302 for single
supply/isolation purposes, as well as 480x320 TFT for
display purposes....
I've got code that works on an Arduino (Mega2560),
however, the pointer resolution, and update speed were too
coarse/slow for my liking.?
(Either PROGMEM and/or the?TFT display is too slow, or
my code is the suck.? (Probably the latter.))? ? ? -- See
the animated IMGUR links off the ARF thread.
I'm working on throwing hardware at it, via a Raspberry
Pico.? ?The increased flash will permit me to try some
code?
optimizations I've thought of that trade off compute
cycles for memory.
?So if someone has highly performant code they'd like
to share, I'm all ears.? I might learn something from it.?
David
Keep going Michael,
?
I like the approach.
?
Kind regards
?
Matthias
?
?
?
?
I had thought about moving the
pointer so that its position on the display represents
the absolute level and its position on the scale
represents the precise level.
Zooming in and out is certainly possible as well.
One of the problems with a low resolution display is
that the character fonts don't scale well so you need
to fine tune the numbers shown on the scale quite
carefully.
On the other hand the processing of data is a great
deal simpler - the 128 x 64 pixel monochrome display
can be fully represented by 1kbyte of ram, a 320 x 240
colour display needs 150kbytes.
So you really do need 150x the processing power and
150x the data transfer rate - or to be a lot smarter
in how it works.
I have some other displays to play with so I'll
experiment with them as well.
MK
|
Re: "Analogue" indication on Oled display
@ David Holland,
Thanks for the info. I took a look at your links and video - the
performance from your Arduino is better than I expected.
I've got some 480 x 320 display with // data input to play with.
My initial goal was to keep it cheap and simple - the Oled
displays are great for that.
A high res full colour display will be much nicer, and much more
work.
I've got some which are powered by FTDI's graphics controller to
try as well ........
First I mean to get the Oled into a state where it can be used,
with a little board on the back with the micro on it. Not planning
isolation at this stage.
Michael Kellett,
MK Electronics Ltd.,
Unit 4,
Greenlaw,
Castle Douglas,
DG7 2LH,
01556 506999
07968 111148
On 13/09/2022 13:40, David Holland
wrote:
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Show quoted text
I've been attacking it this-a-ways....?
?(Screenshot is from my linux/SDL "port")?
There's some other (older) examples?here:?
(Yes, I've been piddling?with it for a long while....)
I've got too many old meters that have multiple differing
scales upon them, depending on what functions are selected,
for a single scale replacement to be entirely satisfactory.
(I'm looking at you, assorted tube testers &
VTVMs...)? ??
While most of my meters still work, I thought it'd be
nice to have a relatively functional drop in replacement.
I'm intending to use an AMC3302 for single
supply/isolation purposes, as well as 480x320 TFT for
display purposes....
I've got code that works on an Arduino (Mega2560),
however, the pointer resolution, and update speed were too
coarse/slow for my liking.?
(Either PROGMEM and/or the?TFT display is too slow, or
my code is the suck.? (Probably the latter.))? ? ? -- See
the animated IMGUR links off the ARF thread.
I'm working on throwing hardware at it, via a Raspberry
Pico.? ?The increased flash will permit me to try some
code?
optimizations I've thought of that trade off compute
cycles for memory.
?So if someone has highly performant code they'd like
to share, I'm all ears.? I might learn something from it.?
David
Keep going Michael,
?
I like the approach.
?
Kind regards
?
Matthias
?
?
?
?
I had thought about moving the
pointer so that its position on the display represents
the absolute level and its position on the scale
represents the precise level.
Zooming in and out is certainly possible as well.
One of the problems with a low resolution display is
that the character fonts don't scale well so you need
to fine tune the numbers shown on the scale quite
carefully.
On the other hand the processing of data is a great
deal simpler - the 128 x 64 pixel monochrome display
can be fully represented by 1kbyte of ram, a 320 x 240
colour display needs 150kbytes.
So you really do need 150x the processing power and
150x the data transfer rate - or to be a lot smarter
in how it works.
I have some other displays to play with so I'll
experiment with them as well.
MK
|
Re: "Analogue" indication on Oled display
I've been attacking it this-a-ways....? ?(Screenshot is from my linux/SDL "port")?
There's some other (older) examples?here:?
(Yes, I've been piddling?with it for a long while....)
I've got too many old meters that have multiple differing scales upon them, depending on what functions are selected, for a single scale replacement to be entirely satisfactory. (I'm looking at you, assorted tube testers & VTVMs...)? ??
While most of my meters still work, I thought it'd be nice to have a relatively functional drop in replacement.
I'm intending to use an AMC3302 for single supply/isolation purposes, as well as 480x320 TFT for display purposes....
I've got code that works on an Arduino (Mega2560), however, the pointer resolution, and update speed were too coarse/slow for my liking.? (Either PROGMEM and/or the?TFT display is too slow, or my code is the suck.? (Probably the latter.))? ? ? -- See the animated IMGUR links off the ARF thread.
I'm working on throwing hardware at it, via a Raspberry Pico.? ?The increased flash will permit me to try some code? optimizations I've thought of that trade off compute cycles for memory.
?So if someone has highly performant code they'd like to share, I'm all ears.? I might learn something from it.?
David
Keep going Michael,
?
I like the approach.
?
Kind regards
?
Matthias
?
?
?
?
I had thought about moving the pointer so that its position on the display represents the absolute level and its position on the scale represents the precise level.
Zooming in and out is certainly possible as well.
One of the problems with a low resolution display is that the character fonts don't scale well so you need to fine tune the numbers shown on the scale quite carefully.
On the other hand the processing of data is a great deal simpler - the 128 x 64 pixel monochrome display can be fully represented by 1kbyte of ram, a 320 x 240 colour display needs 150kbytes.
So you really do need 150x the processing power and 150x the data transfer rate - or to be a lot smarter in how it works.
I have some other displays to play with so I'll experiment with them as well.
MK
|
Re: DC-5.5 GHz signal generator evaluation boad
Yes, there are a development board but its really expensive compared with the excellent used signal generators available. The board don’t includes output leveling and attenuator. The output match is very bad as the frequency goes up as the spectral purity. Needs very good external band filters, leveled amplifier good matched and step attenuator to become an acceptable signal generator. The good phase noise specs are related to numerical controlled oscillators but the implementation derates the spectral purity a very important specification for a signal generator. ? At this point I really prefer old school analog designs for T&M applications.?
Ing. Patricio A. Greco
Taller Aeronáutico de Reparación 1B-349
Organización de Mantenimiento?Aeronáutico de la Defensa OMAD-001
Laboratorio de Calibración ISO 17025?AREA: RF/MW?
Gral. Martín Rodríguez 2159
San Miguel (1663)
Buenos Aires
T: +5411-4455-2557
F: +5411-4032-0072
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Hi all
I looked at the AD9166 datasheet ... and somebody else needs to build
that for me. ?And whoever builds it needs to make it as easy to use as
a 1970s sig gen like the 8640. ?Otherwise I'll keep rescuing these old
boatanchors from the junkpile until I am too old to pick them up.
After that, I guess I'll have to use my General Radio unit oscillators
with a discrete freq counter ($15 from ebay) and a level meter
(junkbox or surplus HP432).
For me, "easy to use" means designing both frequency control and power
output controls that I don't need to look at to use -- IOW, a knob for
each. ?Any engineer who designs these controls three levels deep into
a pushbutton-driven physical interface with a 3" screen is an idiot,
and I would happily fly halfway around the world to beat him senseless
with his own manufactured product.
73
Jim N6OTQ
|
Re: DC-5.5 GHz signal generator evaluation boad
Hi all
I looked at the AD9166 datasheet ... and somebody else needs to build
that for me. And whoever builds it needs to make it as easy to use as
a 1970s sig gen like the 8640. Otherwise I'll keep rescuing these old
boatanchors from the junkpile until I am too old to pick them up.
After that, I guess I'll have to use my General Radio unit oscillators
with a discrete freq counter ($15 from ebay) and a level meter
(junkbox or surplus HP432).
For me, "easy to use" means designing both frequency control and power
output controls that I don't need to look at to use -- IOW, a knob for
each. Any engineer who designs these controls three levels deep into
a pushbutton-driven physical interface with a 3" screen is an idiot,
and I would happily fly halfway around the world to beat him senseless
with his own manufactured product.
73
Jim N6OTQ
|
Re: DC-5.5 GHz signal generator evaluation boad
Hello,
?
some time ago I started to compile an Excel-Spreadsheet with the Phase Noise parameters of various signal generators.
You can find it here:
?
?
I will be happy to add the data of other signal generators. Please feel free to send the data to me.
?
Kind regards
?
Matthias
?
?
?
?
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On 02/09/2022 16:38, Carter, Michael wrote:
Jim, your mention of the HP 8640B made
me curious about the SSB phase noise
specs of the AD9166 system.? At 100 MHz
it appears to be equivalent to that of
the 8640B, but I couldn't find a spec
for the 8640B at 1000 MHz to compare
the two signal generators.? I agree that
the price of the AD9166 and frequency
coverage makes it an attractive alternative,
especially if low SSB phase noise is required
to serve as a reference source.
The 8640B datasheet gives "typical measured" SSB phase noise at 512MHz as -130dB/Hz at 10kHz offset. Option 002 contains an internal doubler, so the phase noise at 1024MHz would be ~6dB more, i.e. -124dBc/Hz.
At 512MHz, it hits the broadband noise floor of -145dB/Hz at 50kHz offset, so the figure at 1024MHz would be somewhere between -145 and -140dBc/Hz, probably closer to -145dBc/Hz.
I don't have one, but I do have an HP8642B, which is even quieter (and incredibly heavy).
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Re: DC-5.5 GHz signal generator evaluation boad
On 02/09/2022 16:38, Carter, Michael wrote:
Jim, your mention of the HP 8640B made
me curious about the SSB phase noise
specs of the AD9166 system.? At 100 MHz
it appears to be equivalent to that of
the 8640B, but I couldn't find a spec
for the 8640B at 1000 MHz to compare
the two signal generators.? I agree that
the price of the AD9166 and frequency
coverage makes it an attractive alternative,
especially if low SSB phase noise is required
to serve as a reference source.
The 8640B datasheet gives "typical measured" SSB phase noise at
512MHz as -130dB/Hz at 10kHz offset. Option 002 contains an internal
doubler, so the phase noise at 1024MHz would be ~6dB more, i.e.
-124dBc/Hz. At 512MHz, it hits the broadband noise floor of
-145dB/Hz at 50kHz offset, so the figure at 1024MHz would be
somewhere between -145 and -140dBc/Hz, probably closer to
-145dBc/Hz.
I don't have one, but I do have an HP8642B, which is even quieter
(and incredibly heavy).
--
Regards,
Tony
|
Re: "Analogue" indication on Oled display
Keep going Michael,
?
I like the approach.
?
Kind regards
?
Matthias
?
?
?
?
I had thought about moving the pointer so that its position on the display represents the absolute level and its position on the scale represents the precise level.
Zooming in and out is certainly possible as well.
One of the problems with a low resolution display is that the character fonts don't scale well so you need to fine tune the numbers shown on the scale quite carefully.
On the other hand the processing of data is a great deal simpler - the 128 x 64 pixel monochrome display can be fully represented by 1kbyte of ram, a 320 x 240 colour display needs 150kbytes.
So you really do need 150x the processing power and 150x the data transfer rate - or to be a lot smarter in how it works.
I have some other displays to play with so I'll experiment with them as well.
MK
|
Re: "Analogue" indication on Oled display
I had thought about moving the pointer so that its position on the display represents the absolute level and its position on the scale represents the precise level.
Zooming in and out is certainly possible as well.
One of the problems with a low resolution display is that the character fonts don't scale well so you need to fine tune the numbers shown on the scale quite carefully.
On the other hand the processing of data is a great deal simpler - the 128 x 64 pixel monochrome display can be fully represented by 1kbyte of ram, a 320 x 240 colour display needs 150kbytes.
So you really do need 150x the processing power and 150x the data transfer rate - or to be a lot smarter in how it works.
I have some other displays to play with so I'll experiment with them as well.
MK
|
Re: "Analogue" indication on Oled display
Is the R &S actually a moving coil meter with an LCD scale - that's very nice but expensive to replicate !
MK
|
Re: "Analogue" indication on Oled display
Rhode & Schwarz used that technique on their URV 35 level meter, it works quite well. ? Regarding comments about accuracy. If the display is used for adjusting a null, sensitivity and stability are more important than accuracy. ? Rodger Bean ?
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From: [email protected] <[email protected]> On Behalf Of saipan59 (Pete)
Sent: Tuesday, 13 September 2022 06:47
To: [email protected]
Subject: Re: [Test Equipment Design & Construction] "Analogue" indication on Oled display? Very nice Michael,
As a variation that is used for "nulling" a signal, how about moving the pointer instead of the scale (like a mechanical meter), but dynamically adjust the *markings* on the scale to match the "recent average" of the signal. So, a low-res meter automatically becomes a hi-res meter as you get closer to the Null.
Or, a similar concept that could be used for *any* application maybe(?):
Initially the scale is wide, to cover the entire dynamic range. But as the signal is averaged over a few seconds(?), the scale "zooms in" to automatically show high precision at any particular value. If the signal starts moving, then it "zooms out" automatically...
Pete
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Re: "Analogue" indication on Oled display
Very nice Michael,
As a variation that is used for "nulling" a signal, how about moving the pointer instead of the scale (like a mechanical meter), but dynamically adjust the *markings* on the scale to match the "recent average" of the signal. So, a low-res meter automatically becomes a hi-res meter as you get closer to the Null.
Or, a similar concept that could be used for *any* application maybe(?):
Initially the scale is wide, to cover the entire dynamic range. But as the signal is averaged over a few seconds(?), the scale "zooms in" to automatically show high precision at any particular value. If the signal starts moving, then it "zooms out" automatically...
Pete
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Re: "Analogue" indication on Oled display
Suffering frequent double vision, I didn't realize at first the double print on the ribbon was not my eyes.
I prefer an analog meter to see changing numbers, but that of course doesn't have either accuracy or resolution. An OLED display of a meter movement with 4 digit readout added, and switch to ribbon for extreme excursions would be nice.
John
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On 9/12/2022 9:45 AM, Michael Kellett wrote: I think there was some mention in this group of the resolution needed on a digital display to make it useable for tuning purposes. This got me thinking about how it might be done and I came with the idea (probably done by HP or whoever in the 1950s :-)? of using a ribbon type display.
I used a 128 x 64 pixel 2.42" Oled display with an SPI interface because these are easy to get and very cheap.
I'm driving it with a and ST STM32G071 micro clocked at 64MHz and the display update rate is about 150 frames per second. (it may not actually update anything at this speed but that's how fast the micro changes the display memory).
The ribbon makes it easy to see which way the signal is moving. In the videos the range is 100dB and the resolution is 0.04dB so I'm getting an effective approx 2500 divisions.
I'm trying to decide if this is worth taking any further and welcome any comments.
Videos at:
<>
(if the link doesn't work right away try again later - my upload speed here is very slow)
MK
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Re: "Analogue" indication on Oled display
I've done a similar, but simpler, version of this concept. I use 2 red/green bargraphs which can be mounted end-to-end with the green ends touching (or nearly so). In order to achieve decent resolution for my purposes (indicating a null), I vary the sensitivity according to how far off null the system is. i.e., for the 2 innermost green segments, only a small voltage change is required to light the next outer segment; for that segment, double that voltage change is required, etc. - with the sensitivity decreasing by a factor of 2 for each increment away from null. I don't use a computer since the instrument does not have an embedded processor. Logic and analog can do it.
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Re: "Analogue" indication on Oled display
Timely because I am in the 'I need that'
stage to monitor the output power of my VHF/UHF transverters.
?
Paul, W8AEF
?
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From: [email protected]
[mailto:[email protected]]
On Behalf Of Michael Kellett
Sent: Monday, September 12, 2022
9:46 AM
To: [email protected]
Subject: [Test Equipment Design
& Construction] "Analogue" indication on Oled display
?
I think there was some mention in this group of the resolution needed
on a digital display to make it useable for tuning purposes. This got me
thinking about how it might be done and I came with the idea (probably done by
HP or whoever in the 1950s :-)? of using a ribbon type display.
I used a 128 x 64 pixel 2.42" Oled display with an SPI interface because
these are easy to get and very cheap.
I'm driving it with a and ST STM32G071 micro clocked at 64MHz and the display
update rate is about 150 frames per second. (it may not actually update
anything at this speed but that's how fast the micro changes the display
memory).
The ribbon makes it easy to see which way the signal is moving. In the videos
the range is 100dB and the resolution is 0.04dB so I'm getting an effective
approx 2500 divisions.
I'm trying to decide if this is worth taking any further and welcome any
comments.
Videos at:
(if the link doesn't work right away try again later - my upload speed here is
very slow)
MK
|
"Analogue" indication on Oled display
I think there was some mention in this group of the resolution needed on a digital display to make it useable for tuning purposes. This got me thinking about how it might be done and I came with the idea (probably done by HP or whoever in the 1950s :-)? of using a ribbon type display.
I used a 128 x 64 pixel 2.42" Oled display with an SPI interface because these are easy to get and very cheap.
I'm driving it with a and ST STM32G071 micro clocked at 64MHz and the display update rate is about 150 frames per second. (it may not actually update anything at this speed but that's how fast the micro changes the display memory).
The ribbon makes it easy to see which way the signal is moving. In the videos the range is 100dB and the resolution is 0.04dB so I'm getting an effective approx 2500 divisions.
I'm trying to decide if this is worth taking any further and welcome any comments.
Videos at:
(if the link doesn't work right away try again later - my upload speed here is very slow)
MK
|
Re: 10 MHz reference inputs
On 9/12/2022 5:50 AM, Dr. David Kirkby,
Kirkby Microwave Ltd wrote:
the amount of service information in Keysight manuals is next to
useless
Not just the service manuals.? The user manuals on their
current gear are largely useless and frequently flat wrong.
--
mailto:oz@...?
Oz;? POB 93167; Southlake, TX 76092 (Near DFW Airport)
If electricity comes from electrons, does morality come from morons?
|
saipan59 (Pete)
Patricio A. Greco
Tony Casey
John Kolb