STM32F103 any good?

[old gregg]

I suggest that you should start with examples provided by ST instead of reinventing the wheel. Besides, all STM32F103 chips have internal temperature sensor so it could be a good starting point for verifying your theory.

i've actually tried that as well and any of those examples worked.

[Brutte]

At the moment I've terrible experience with the ADC, it simply doesn't work (..)
i've actually tried that as well and any of those examples worked.

Sounds like a contradiction.

[old gregg]

oups...I meant none of the example worked.

the ADC OEC flag is set and working but nothing moves in the ADC data register.

[Kilrah]

And about the bootloader - the chip has USB device peripheral and ST provides DFUse.

The F1s however don't have the DFU bootloader, only F2 and up.

[Rasz]

And about the bootloader - the chip has USB device peripheral and ST provides DFUse.

The F1s however don't have the DFU bootloader, only F2 and up.

http://libopencm3.org/wiki/USB_DFU

[Brutte]

oups...I meant none of the example worked.

What have you done to that poor uC?  It is hard to blame a uC when other (last week at Nuremberg ST stated 1.6 billion of them) work as expected. Can you tell us something about your hardware design? Perhaps get some reputable f103 eval (nucleo) to run ST examples. BTW, the f103 is used in numerous USB scope designs as even smallest versions are capable of converting 2x1Msps at 12-bit resolution.

The F1s however don't have the DFU bootloader

in ROM but you can download anything to flash. Of course there is this chicken-egg problem at the beginning. Just my remark about using a USB-to-serial converter to upgrade a USB chip.

[dadler]

Is there any real reason to use these when the F410 is about the same price with better specs?

http://www.mouser.com/Search/ProductDetail.aspx?R=STM32F410RBT6virtualkey51120000virtualkey511-STM32F410RBT6

[dannyf]

In many cases costs are not the only reason or even a major reason to pick a part.

[old gregg]

What have you done to that poor uC?

you guessed it....I've fried it it seems (or at least the input).

I used a second identical one and it worked as expected. Go figure what I've done to that uC.

Is there any real reason to use these when the F410 is about the same price with better specs?

it was cheap, small enough for what I want to do with it and easy to manage for one-off project.

[Brutte]

What have you done to that poor uC?

you guessed it....I've fried it it seems (or at least the input).

I have made some remarks about STM32 IOs at the beginning of this topic. Not all IOs are 8V tolerant. However, that does not explain how come the internal temperature sensor misbehaved. Perhaps you have fried a multiplexer or ADCs..

[old gregg]

I must have coocked the input driver or something. I'll check if the logic driver still work or not. I hate Breadboard for that kind of crap... (or it may as well be the uC which was already dead on the inside ... just to pretend I'm not responsible )

[rexnanet]

I've known ST microcontrollers existed for a long time but haven't really used any.

But after getting very frustrated with a PIC32MX that didn't want to work (or failled after a few flash writes) (maybe because of cloned pickit lol) I quited! $%#$% them!

I'm also using a Stellaris Launchpad (now TIVA) to do some projects but it's a bit pricy to have a board for each project.

Then I saw that some people got F103 overclocked (up to 128M) and some other guys got it to work with arduino IDE (I'm not a big fan of arduino but it has lots of code already done...) I started to get interested.

Then I saw the price!!! 2-3€ for a board and 2-3€ for a programmer?!?! "Thats worth giving a try!"

It's fast I've managed to get SPI and I2C working with the master clock at 128Mhz and its faster than the Stellaris!
It has fewer pins but for small projects it's enough. For bigger ones I'm getting a F429 and also a F746.

There are not many ready made examples to get started but going step by step it's fairly easy to get stuff working.

[Sal Ammoniac]

It's fast I've managed to get SPI and I2C working with the master clock at 128Mhz and its faster than the Stellaris!

Do you really need the extra speed enough to risk running the part at a clock rate well above what it's specified for?

[rexnanet]

Do you really need the extra speed enough to risk running the part at a clock rate well above what it's specified for?

In this case yes

First, I'm just testing the micro to see what it's capable of.
Second, Im not making anything that has a risk involved.
Third, I'm using it to interface a SPI TFT, so more speed=more fps=nicer interface

Yes, it's a risk and it might fail but for this purpose it's not a big deal.

[TonyD]

I'm a bit late to the discussion but I'd just to say we've been using the STM32F103RB at work for the last 5-years or so, in about 30 products will in total volume of 40K+ pieces a year. We found it a fine uC and good support from ST (sorry for the flag waving). It must have something going for it if its being copied by a far-east company ;-)

[dannyf]

if its being copied by a far-east company

GD......,

I suspect many of the 103s on ebay are actually GD.

[martinayotte]

I suspect many of the 103s on ebay are actually GD.

GD are not fake/clone of STM, only that they are almost compatible.
So, pictures of board on eBay that showing STM should be STM. Boards with GD will cleary show the GD logo.

[michaeliv]

GD are not fake/clone of STM, only that they are almost compatible.
So, pictures of board on eBay that showing STM should be STM. Boards with GD will cleary show the GD logo.

Any reason to think that they are genuine other than the rock-solid trustworthiness of Chinese sellers ?
I think he was saying that the STM32 chips are re-branded GD32 chips.
Kind of like how certain op-amps & voltage references are re-marked and sold for higher prices (happened to me).
Are the GD32 / STM32 chips not 100% compatible ? Does anyone know any differences between them ?

[stmdude]

Are the GD32 / STM32 chips not 100% compatible ? Does anyone know any differences between them ?

They seem to be at least very compatible. There's no way of testing every single gate in them.

Olimex got in contact with GigaDevices, and got samples to test:
https://olimex.wordpress.com/2015/12/21/gd32f103rbt6-the-stm32-pin-to-pin-compatible-chinese-mcus-sample-test/

[dannyf]

Are the GD32 / STM32 chips not 100% compatible ?

The demo I have seen suggests that they are binary compatible. You can also use ST libraries to develop for GD32, .

From a hardware perspective, the GD has a newer core, runs faster, and has a "working" I2C module - the I2C module on F1 is not exactly flawed. Just that they are not compatible with ST library but that's more (but not a complete) an indication of ST software developers than its hardware developers.

The only known issue (that I'm aware of) is that the GD chips have a noisier ADC.

[michaeliv]

the GD has a newer core, runs faster

Do they actually run faster or is it more a case of "well we clocked it higher at 25C and it worked for us, mark it faster in the datasheet".
As in, if you clock the STM32 & GD32 at 120MHZ, the STM32 will give errors when the GD32 will not ?
Also is there a software way to tell which chip is which, like FTDI detected managed to detect non-FTDI chips? I'm asssuming that measuring ADC noise would not be that reliable.

[dannyf]

GD32(F103) runs at 108Mhz, on a r2p1 core, with WS0 flash. Whether that translates into actual faster speed all depends on what you are "running" on it: Reading from flash for example is much faster. Writing to flash is considerably slower however.

There are also some well-known differences as well.

One of the frustrations with GD32 has been the inability to tell it apart from STM32 using software alone.

[martinayotte]

Yes, GD and STM are almost compatible. One difference that I know is that PLL has more bits to provide more frequency ratios, for example, to get proper USB clock even if MCU isn't at the same frequency as STM.

BTW, for those who wish to see that the GD die isn't a clone of STM at all, here is a nice link, which also explain why the Flash is much faster on GD than STM :

http://zeptobars.com/en/read/GD32F103CBT6-mcm-serial-flash-Giga-Devices

[savril]

Are the GD32 / STM32 chips not 100% compatible ?

The demo I have seen suggests that they are binary compatible. You can also use ST libraries to develop for GD32, .

If I'm right, the SDK for GD32 was a carbon copy of STM32 SDK only with the ST copyrights removed (GD have changed some source files since the launch however).
There is a legal complaint from ST and that source copy seem an advantage on ST side.

Even if they can't forbid the chip as it is not a silicon copy, ST may be able to make all software developed with their SDK illegal to run on non ST chips. And so all products made with ST SDK (or GD copied one) could be marked as counterfeits...

As a hobbyist, I don't care. But if I was making a product, I would think twice before including a GD chip in my design.

[dannyf]

the SDK for GD32 was a carbon copy of STM32 SDK

Some changes to the stm libraries are needed to support the higher clock rates. Other than that, you can literally use the stm32 library to develop code for gd32.