Just a quick posting about some STM32F1XX based boards which seem to popped up recently on eBay, with Arduino in their description
The fist one I noticed was this one
TM32F103C8T6 ARM STM32 Minimum System Development Board
Although these devices have Arduino in their title, its a bit missleading, as its impossible to use them as with the normal IDE and they require both additional hardware files, (see my next post) and also a USB to Serial adaptor to upload code into the board
This board seems to have been designed and produced by a Chinese company called vcc-gnd
This board claims to have an RTC, but its unclear what this is, where its attached or how to use it.
Next up this this board, which is described as
STM32 ARM Cortex-M3 Leaflabs Leaf Maple Mini Module for Arduino
This board is a clone of the LeafLabs Maple mini board, it differs from the previous board in that it has 2 buttons, and also some additional hardware to allow the board to reset its own USB connection (to force the PC to re-enumerate the USB bus)
The schematic for this board can be found on GitHub https://github.com/leaflabs/maplemini/blob/master/maplemini.pdf?raw=true
Like with the Minimum system board, this one also needs new “hardware” files to be added, so that the board is supported by the Arduino 1.5.x IDE
This board however can be programmed without the use of a USB to serial converter, however setting up the PC to do this is no easy matter under Windows 7 or newer (and possibly also hard on Windows Vista).
The problem is that, the board requires custom USB device drivers to be installed, which are not digitally signed, and under Windows 7 onwards, all drivers must be digitally signed.
There are various work around’s for the driver signing issues, which mainly revolve around booting windows into a special mode where the requirement for signed drivers has been removed. However every time the PC is booted, this setting needs to be set. (There are automated ways to set this at boot time, but most of them are in my opinion borderline usable, and also leave your system open to possible virus infection etc because of the potential of other unknown drivers being maliciously installed by a virus etc (which I suspect is why MS now require driver signing)
Another variant on the generic STM32 minimum board appears to be this one
I have one of these on order, but have not received it yet (I will update this post when it arrives)
The board appears to be almost identical to the other non- Leaflabs clone, except it has an additional jump link (unknown use at the moment)
I have one of these on order and will update this post when it arrives and I can give more details about its compatibility with Arduino