Geehy APM32F407 as STM32F407 replacement, does anyone use?

[up8051]

Hi,

I am trying to replace the STM32F407VGT6 chip with Geehy APM32F407VGT6 chip.
Unfortunately, I only have access to the BIN File, (PIN2DMD project for pinballs).
At first it seemed like everything was fine (I have two devices: first with ST second with APM and the same firmware), all device functions work (USB, SD CARD, UART ...).
But there were some performance issues with the animation displaying: dropping frames.
A short video showing the problem:
https://drive.google.com/file/d/1GzR-Issybevt_F9sV32YMADpYpionxpl/view?usp=sharing
Upper = ST chip
Lower = Geehy chip
both have the same firmware (PIN2DMD V4.37).
As you can see in the video, in the case of APM, animation frames are lost.

Does anyone use these chips?
Has anyone found a difference in the operation of STM and Geehy?

I am also sending a request to FAE but I don't have an answer yet.

BR JarekC

[ozcar]

Unfortunately, I only have access to the BIN File, (PIN2DMD project for pinballs).

With that constraint, it sounds like an overly optimistic hope.

But then I never heard of pin2dmd, so I took a look, and just about the first thing I find, straight from the horse's mouth, is "Please make sure you buy a genuine STM board. Cheap chinese copies may cause problems and are not supported."

[up8051]

PIN2DMD is a well-known project among pinball owners.

https://pin2dmd.com/
https://github.com/lucky01/PIN2DMD.

The APM32F407 was the first replacement that appeared to be binary compatible.
The author of PIN2DMD that I contacted suggests problems with interrupts.

I am looking for other users of Geehy processors.

BR JarekC

[peter-h]

Interesting. I am using the 417 (crypto add-on) but the APM32F407 seems to include that.

Can't find any pricing. Who sells these?

[up8051]

Local electronic wholesaler, price is about 15€ +VAT    (+10pcs)

I got a reply from the FAE:  APM has NVIC with 8 levels, STM has 16 levels.
And here is the cause of the problems.

[peter-h]

Where is this wholesaler? Nothing on google.

€15 is not cheap; I have bought 500 x 32F417 100 pin QFP for GBP 5.20. Took a while to turn up but they did. I would not buy a chinese "407" unless it was something like $2. Too much risk...

Why these "copiers" emulate 99% of the ST chip and not the other 1%, I don't understand. It's a strange mentality, and I'd say not untypical of the culture (make a fast buck and move on). They would get 100x more sales if they did it properly.

[up8051]

The problem is also that they don't exactly describe the difference?

I tried to find a supplier for the F407VGT6 / 417VGT6 at a reasonable price but I failed.
The lowest price for STM I got from Chinese suppliers is $ 28, but I don't trust them.
You can get e.g. F404VET6 remarked to F407VGT6.

That's why I tried Geehy,  they have a local distributor in my country.

[peter-h]

NVIC with 8 levels, STM has 16 levels.

That is either in the data sheet, or it isn't. That's quite a big thing. Not a problem if you are the coder but a lot of binaries won't run.

You can get e.g. F404VET6 remarked to F407VGT6.

Well, with everybody and their dog in China counterfeiting everything that can be counterfeited... I posted about the fake Maxim MAX3089 chips which we got burnt with.

BTW the 407 datasheet
https://www.geehy.com/uploads/tool/APM32F405xG%20407xExG%20datasheet%20V1.1.pdf
does not mention any crypto features. That would be a 417.

[up8051]

Unfortunately improving the interrupt handling

Code: [Select]

#define __NVIC_PRIO_BITS 3U /*!< APM32F4XX uses 3 Bits for the Priority Levels */ did not fix the problem 

[DavidAlfa]

Stop being Geehy, be STraight!  (No pun intended)
Sorry, the joke was too easy

[mon2]

While our review of this line is still ongoing..had to source some extra tools which took some time...wish to share a great contact @ factory.

Steve <removed last name for privacy>
Field Applications Engineer
< removed phone # for privacy > ;  PM if it is of interest
steveg[at]as2inc.com
APEX Semiconductor USA/Geehy Semiconductors USA
https://www.apexsemi-usa.com/

and for a sales contact:

Apex Semiconductors (USA) Company Limited
3010 Lee Avenue Sanford, NC 27332
< removed phone # for privacy > ;  PM if it is of interest
marks[at]geehy.com

So far, the support from the US contacts has been excellent.

[up8051]

I correspond with:
Field Application Engineer  Geehy Semiconductors Co., Ltd
Larry Lai
Email: larry.lai[at]geehysemi.com

I can't understand why they won't make a list of the differences between APM and STM.
and application note of the type "Migration from STM32F4xx to ATM32F4xx".
It is difficult to compare 1,000 pages of documentation by yourself.

For now, I am waiting for the answer if there are any other differences apart from NVIC priority levels.

[robots]

Sorry to resurect older thread, but there is no place on net that discusses this topic.

We are researching usage of APM32F407xG.

One very obvious problem we found is that the ADC calibration in system memory is missing. (non existent)

Second problem, and i dont know it thats just me. The device is supposed to have 192kB of memory, but debugger fails to read memory, and starts reading at 128k mark (going backwards, scrolling memory view in eclipse). So there is only 128kB of ram.

[wek]

Second problem, and i dont know it thats just me. The device is supposed to have 192kB of memory, but debugger fails to read memory, and starts reading at 128k mark (going backwards, scrolling memory view in eclipse). So there is only 128kB of ram.

And if you do the same in STM32F407?

JW

[robots]

OMG, 

you are correct. I have gotten very confused on this one. Of course there is 64kB of CCM ram.
:-)

[peter-h]

Cube can do some funny stuff
https://www.eevblog.com/forum/microcontrollers/is-st-cube-ide-a-piece-of-buggy-crap/msg4316272/#msg4316272

The APM32F407xG looks interesting. I wonder why they call it 407 when they seem to have the crypto stuff which the ST 417 has. But I wonder how complete it is. Is it available? I can't see anyone selling it.

I looked at the ADC calibration feature of the ST 417 and decided to do my own one in factory test.

[up8051]

APM32F407 don't have crypto module.

[peter-h]

https://www.geehy.com/apm32?id=49
says so. But no mention in the data sheet.

I would be amazed if this was a drop-in replacement for a 32F4x7 for example. There are so many critical details in the peripherals. Could they have been synthesised with the same sourcecode?

ADCs are always custom designed, hence I am not surprised they could not get it to work the same way.

[up8051]

APM32F4xx User Manual page 296

HASH processor (HASH)
Note: Only APM32F415xG/APM32F417xExG series products have such module