STM32 Nucleo, The Mbed-Enabled, Arduino-Compatable Board

The STM32 line of microcontrollers – usually seen in the form of an ST Discovery dev board – are amazingly powerful and very popular micros seen in projects with some very hefty processing and memory requirements. Now, ST has released a great way to try out the STM32 line with the Nucleo board.

There are two really great features about these new Nucleo boards. First, they’re mbed compatable, making them a great way to get started in the ARM development world. Secondly, they have Arduino pin headers right on the board, giving you access to all your shields right out of the box.

Right now, there are four varieties of the Nucleo board based on the STM32F030, -F103, -F152, and -F401 microcontrollers. The STM32F401 is the high-powered variant, An ARM Cortex-M4 microcontroller running at 84 MHz, 512kB of Flash, and enough I/O for just about any project.

If you’d like to get your hands on one of the STM32 Nucleo boards, you can order a voucher to pick one up at Embedded World in Germany next week. Otherwise, you’re stuck ordering from Mouser or Farnell. Bonus: the high-end F401-based board is only $10 USD.

OpenMV: The Camera For Your Next Project

Camera

Last month we saw [Ibrahim] tackle the lack of cheap, high speed, high resolution serial cameras with full force. He designed a serial camera based on the STM32F4 microcontroller that’s the perfect solution to anyone wanting to add visual processing or machine vision to a project. It’s cheap, too: instead of the $100 or so you’d spend on a high-end serial camera, [Ibrahim]‘s version only has about $15 in parts.

Now he’s back at it again, with 25 FPS face detection, 30 FPS color detection, a new board with a micro SD socket, and support for USB OTG full speed. [Ibrahim] has been hard at work deep in the bowels of the STM32F4 micro, playing around with the core coupled memory. This allows for some very fast image processing, combined with the micro running at 168 MHz makes for very fast face and color detection.

As for a few benchmarks for this camera, the maximum resolution is 1280×1024, and at 88×72 resolution this little board can output at 60 FPS. Of course everything is limited by the speed of the serial connection, but there’s a lot of potential in this small serial camera.

No word on how much this board will cost, but [Ibrahim] may be putting a few boards up on Tindie shortly. Here’s to hoping he’ll send us an email telling us when his store is open.

Breadboard Friendly ARM Board Based on STM32F4

breadboard-friendly-stm32-dev-board

Umm yeah… this is more like it. The STM32F4Stamp is a project which [Frank Zhao] put together to make his ARM prototyping process more like is was back when everything came in a DIP format. As you can see, it’s just narrow enough to leave one row open on the breadboard for jumper wires.

Don’t get us wrong, we do really like STM’s own Discovery Boards for the hardware they deliver at a very low price. But the dual-row pin headers on the larger versions (all except the F0 variant) make it tricky to connect your peripherals. This is pushed to the point that a large percentage of hacks we’ve seen with the Discovery boards are actually just to make connecting external hardware easier.

You may be thinking that there’s a lot missing from this board, but we disagree. Obviously there’s still a USB port which can be used to power the board via a 3.3V regulator. But since the STM32 chips have a built-in bootloader the USB connection can also be used to flash firmware to the processor. Nice! It’s open hardware if you want roll your own. For your convenience we’ve embedded the schematic after the break, along with [Frank's] demo video.

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UDP between STM32-F4 Discovery boards

stm32-f4-udp

[The Backwoods Engineer] tested out a new accessory kit for the STM32-F4 Discovery board. The image above shows two boards communicating with the UDP protocol. Notice the extra PCB into which each Discovery board has been plugged. This is a third-party add-on which adds Ethernet, RS-232, SD card slot, and a connector for LCD or Camera. We’ve had one of these F4 Discovery boards on hand for a while and haven’t figured out a good way to connect external hardware to the huge dual pin-headers. This doesn’t solve the problem — the base board also includes dual headers to break-out all the pins — but having Ethernet, serial, and SD certainly reduces the need to add all that much more. The other drawback to the hardware is that the sample firmware is targeted at the IAR Embedded Workbench which is neither free, nor in the realm of affordable for hobbyists.

The NIC used on the baseboard has auto-crossover capabilities so the boards were connected using a regular Cat6 patch cable. This example has the boards constantly sending UDP packets with the module on the right reporting status information to a terminal via the serial connection.

A guide and helper script for ARM cross compiling toolchain on a Mac

mac-arm-toolchain-script

[Mitchell Johnson] wanted to develop for the STM32F4 Discovery board on his Mac. There are a few ready-to-use options when it comes to the ARM toolchains, but he couldn’t find one that satisfied all of his needs. After working out all the kinks he wrote a guide and tweaked a script to install the ARM tools on a Mac.

The problem he had with some of the pre-packaged tool chains is that they didn’t support the hardware floating point functionality of STM’s Cortex-M4 chips. To get around this without doing his own ground-up build (which can be quite a challenge) he forked the Summon Arm Toolchain script and modified it to include ST-Link support in the build. One of the things that we like about that script is it installs the tools in a sub-directory of your home directory. This way if you already have another ARM toolchain you can switch between the two by tweaking your PATH variable.

[Scot] whips up breakout board for his ARM breakout board

[Scot Kornak] got his hands on the new STM32 Discovery Board. He got his as a free giveaway, but at only $18 he probably would have picked one up anyway. His one complaint about the device is that he dual pin-headers which break out the ARM processor’s pins are not the most convenient for hooking up external components. He decided to make his own breakout board which would give him a more robust solution for the components he uses all the time.

The protoboard that he chose as a base is quite interesting. It’s made for interfacing DIL pin headers just like the ones on the STM32F4 Discovery board. Each row of the dual header is carried down the board perpendicular to those headers. [Scot] cut the traces underneath the STM32 board to isolate the right and left sides. He then added RS232 hardware to one side, while including another pair of DIL headers to break out the rest of the unused pins.

This is all he’s got so far, but there’s plenty of room on the base board to add more as the need arises.