Olimexino-STM32
Slammer Tue May 31, 2016 12:33 am
First, the board is not new, it is available for at least 6 years, mine is purchased in 2011 and it is revision B.
The board is an improved version of original maple. All pins are in the same location as in maple board.
The board comes with the official bootloader which can be replaced with bootloader V2. It is fully compatible with arduino-STM32 as maple board.
In comparison with Leaflabs Maple the improvements are:
– Switching power regulator for improved efficiency and wide input voltage (9-30V). It is based on well known (but a bit old) MC33063 regulator.
– On board Li-Po battery charger with automatic power supply selection. MCP73812 charger is used, adjusted at 70mA charging current.
– Separate 3V3 regulators (MCP1700) for digital and analog power planes.
– On board CAN interface and micro-SD slot.
– Custom UEXT connector for external peripherals (Olimex has many UEXT boards, like RS485, Ethernet, etc)
– RTC support ready (XTAL is here and Vbat to Battery connector)
– 2 User Leds
I didn’t like:
– SWD connector with 10 pins, spaced at 0.05”. A special adapter cable required for connecting ST-LINK.
– The power supply capacitors and inductor are very tall, any shield on top of the board cannot be placed correctly. I think that they corrected this problem in later revisions.
I like this board mainly bacause of the flexible power supply input. It can be powered directly from a 24V industrial supply. From the value of Rsc of MC33063 the cutoff current of regulator is about 1200mA, but the inductor is a bit small for this current, anyway the regulator can supply more than 500-600mA easily in 5V plane. For 3V3, two MCP1700 are used rated at 250mA.
It costs about 20$-25$ and it is rather expensive in comparison with chinese STM32 boards
