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LadyN

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Joined: 26/01/2019
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Posted: 08:16pm 13 Feb 2019

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Dave, which specific boards did you order?

Andrew, if I build the STM-O-Scope, then flashing your firmware to the board is all that's needed to run and use this project right (no extra hardware needed)

I am excited to get started!

mackoffgrid

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Posted: 09:17pm 13 Feb 2019

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Hi N,
My Project as it sits uses the parallel LCD, whereas the stm-O-Scope uses a SPI LCD.
The link to the LCD I use is in my second post.

The analog Pins are the same.

If you use the SPI LCD, My code will work but you would have to change the LCD library.
If you use the parallel LCD, STM-O-Scope should work but you would need to use the libraries I used.

In either case you would have to change defines of the relevant port pins for LCD.

It would be no biggie either way.

I am drawing a PCB as per the Schematic I posted. You will be able to use either LCD.

I have no idea which LCD is actually faster but I will presume the parallel is faster.

The STM-O_scope as per Andrew Hull's github doesn't have any buttons or encoders but some of the variations of it do, I have not taken this into consideration when drawing the schematic as I want the PCB to be small enough to fit behind the LCD. I do provide 9 port pins which are un-allocated on headers just in case.

The parallel 2.4" LCD is quite a bit cheaper!

Cheers
Andrew

davef
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Joined: 14/05/2006
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Posted: 09:25pm 13 Feb 2019

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LCD
... without touch

STM32 board Edited by davef 2019-02-15

LadyN

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Posted: 11:02pm 13 Feb 2019

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Thank you Andrew, Dave.

I don't see very well even with my magnifying glass like glasses on so that little LCD will be hard to use for me. I will buy it anyways as its affordable and I need to start with a working build before I start changing it.

My computer has a big screen and high contrast so that I can see better.

I will take the excellent work you have done and modify the firmware to not need the LCD so I can use a computer client instead - my concern is the bandwidth/speed limitation of USB serial but we will see when we get there.

I am assuming we are using both the ADC channels with DMA, which will allows us to do the max sample rate, hence freeing up the processor to do high speed USB in the first place.

davef
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Posted: 11:15pm 13 Feb 2019

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STM32 dev board

Think the first attempt was incorrect

mackoffgrid

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Joined: 13/03/2017
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Posts: 460

Posted: 12:46am 14 Feb 2019

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Dave,
That LCD has the SPI interface, directly compatible for STM-O-Scope. I note thats its still 240x320 like the 2.4" model.

My preference is
LCD 2.4" 240x320 parallel, mcufriend
LCD 3.5" 320x480 parallel mcufriend

Natalie,
Referring to the schematic I posted - I have made effort to make the PCB compatible with both projects. The analog front end is simple, and using through hole parts, once populated may not suit both projects? but it could.

Using a 3 resistor configuration I can use a transformer secondary as an input, (I'm using a 9vac-measured transformer on my bench) but when I use a module like the ACS712 module I'll leave the pullup resistor out and change the values to translate the 5v signal to 3.3 volt.

Cheers
Andrew

davef
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Posted: 04:30am 14 Feb 2019

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There appear to be a lot of threads on the Arduino for STM32 forum about issues with mcufriend LCDs. But if you have that sorted great.

Can't find that one on Aliexpress.Edited by davef 2019-02-15

mackoffgrid

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Posted: 05:13am 14 Feb 2019

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This is the same as I used, LCD 2.4" 240x320 parallel from ailExpress.

davef
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Posted: 06:06am 14 Feb 2019

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Hi Andrew,

I should have said that I can't find the 3.5" you referred to on Aliexpress.

I will order a couple of the units above just so I have an easy path to success!

mackoffgrid

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Posted: 07:06am 14 Feb 2019

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Dave,

No worries. you're right they are scarce on aliExpress.
LCD 3.5" 320x480 parallel - China ebay
LCD 3.5" 320x480 parallel - AliExpress - more expensive

davef
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Posted: 08:40am 14 Feb 2019

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But it was there!

mackoffgrid

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Posted: 09:26am 14 Feb 2019

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Inside the Zip are the eagle files, and Gerber files and current PDF of schematic.
You can use Gerbv to view Gerber files.
2019-02-14_191147_PowerScope_004_20190214_1.zip

After review, I am going to order this PCB with some others I am doing. This may take a week or two for me to get the other boards ready. Standard order qty is 10, I want about 4 or so, the rest will be up for grabs at cost.

The PCB is 2.8" x 2.1".

Maybe Mike (wiseguy) might have some ideas of using the rest of the 100mm x 100mm ?

Cheers
Andrew

wiseguy

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Joined: 21/06/2018
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Posted: 12:48pm 14 Feb 2019

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I dont know why the size was designed as 2.8" x 2.1" - I have not been following the thread closely but if it is not a rigid constraint, rearrange the board slightly to 100mm x 49.5mm and place 2 on the 100x100mm and then you can get 20 units back for the same price....

I just finished assembling my inductance/saturation tester and am pleased with the results so far (after debugging my inverted current sense and drive polarity inversion it actually worked). I use a variable pulse width with a variable repetition rate. For a saturation current starting at 30A it is only drawing ~ 200mA from a 20V supply !. Using the Warp forward converter style drive with diode recovery.

Now if only I could remember the l=di/dt crap I can figure out what it all means.....

If at first you dont succeed, I suggest you avoid sky diving....
Cheers Mike

mackoffgrid

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Posted: 08:01pm 14 Feb 2019

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Mike, the PCB does have constraints as it is back packing 2 different LCD's with connectors near the cut line on 3 sides.

I am also interested in the inductance / saturation tester - worthy of a topic of its own.

Cheers
Andrew

davef
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Posted: 09:22pm 14 Feb 2019

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Andrew,

If the shipping to NZ is reasonable I will take 2 or 3.

Dave

mackoffgrid

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Posted: 12:34am 15 Feb 2019

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Australia Post to NZ
Economy Air (click on Letters)
Letter 50g AUD 2.10
" 125g AUD 4.20

My kitchen scale estimate, each board is approx 12 grams.
Each pcb will be somewhere between AUD $1 to $2.50, will depend on what else I order.

Cheers
Andrew

davef
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Posted: 08:30am 15 Feb 2019

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Thanks. Make it 2 or 3 depending on any other requests you get.

DaveEdited by davef 2019-02-16

LadyN

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Joined: 26/01/2019
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Posts: 408

Posted: 06:40pm 15 Feb 2019

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mackoffgrid said

I am also interested in the inductance / saturation tester - worthy of a topic of its own.

YES! YES!

Andrew, should I create the topic or can you?

That project will be VERY useful

mackoffgrid

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Posted: 12:35am 21 Feb 2019

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I received my 3.5" MCUFriend LCD, - it did NOT have a touchscreen. (So /I have ordered another with touchscreen). The packet is labeled 3.5" UNO Module, Driver:ILI9486.

The original library I used does not drive this particular LCD so I'm now using "MCUFRIEND_kbv" by David Prentice. https://github.com/prenticedavid/MCUFRIEND_kbv

This library drives both the 2.4" and the 3.5" LCD's.

I have attached my copy of the library because I had to modify "utility/mcufriend_special.h" to accommodate the pins I have used. This is the correct file for such changes but changing it is not for the faint-hearted. A #DEFINE has been added to "mcufriend_shield.h" so that the mcufriend_special.h is used.

2019-02-21_102955_MCUFRIEND_kbv-INVERTERSCOPE.zip

Some changes were required for the new library.

2019-02-21_103331_InverterScope_kbv.zip

Cheers
Andrew

davef
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Posts: 499

Posted: 05:29am 13 Mar 2019

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Hi Andrew,

Got my STM32 dev boards and 2 types of LCDs. Did you go ahead with the PCB order?

Thanks,
Dave

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