In-depth comparison at STM32 F3 and F4 discovery boards

The STM32 F3 and F4 Discovery boards have been around for a while now. We’ve looked at both separately and they’re impressive dev boards for the price. Now can get a closer look at each from this in-depth comparison of the two Cortex-M4 development tools.

To start off, both of the boards have the same size and footprint (there are two dual-row pin headers which break out the connections to the ARM chip). Fundamentally the F3 and F4 chips have a different level of features, but the boards themselves are aimed at different applications as well. The F3 series of microcontrollers looks to be more affordable than the F4, containing less program memory, no Ethernet capability, and only one USB port. But both have hardware floating-point abilities and they’re blazing fast. The boards offer a MEMS accelerometer for prototyping. But the Discovery-F3 also contains a gyroscope while the Discovery-F4 provides audio hardware like a microphone, and DAC.

If you want to use a Linux box to develop with these tools you might find this guide helpful.

.NET for the STM32 F4 Discovery board

Here’s a technique that will let you use the .NET framework on an STM32 Discovery board. [Singular Engineer] was happy to learn that the .NET Micro Framework had been ported for STM32 chips. It’s doesn’t look like the port has hit a stable version yet, but these instructions will be enough to get you up and running. This lets you use managed code in the C# language to program an embedded device: the STM32 F4 Discovery board.

After flashing a new bootloader to the board a driver needs to be added for Windows to communicate with it. Above you can see that the board will enumerate as ‘STM32 .Net Test’. Once the driver is installed the rest of the firmware can be loaded on the board using a GUI supplied with the NETMF for STM32 package. That takes care of prepping the hardware, the rest is a painless process of configuring Visual Studio to use the board as a target. The ‘Hello World’ application then uses C# to blink an LED.

ARM-based debugging tool aims to improve on the Bus Pirate performance

The Bus Pirate is a fantastic development tool. It does an amazing job at a lot of different things. And as it has matured, community support has driven it to new areas beyond the original design. This is where its hardware holds back performance a little bit. For instance, as an I2C or SPI sniffer it has limited capture speed. That’s the type of thing that this board could improve upon. It’s a debugging tool based on an STM32 F4 microcontroller. That’s an ARM Cortex-M4 chip which runs at 168 MHz, and has 192 KB of SRAM.

[TitanMKD] has been working on the design but it is still just in digital form. Since there’s no prototype there is also no firmware for the device. That’s a tall mountain to climb and it’s one of the reasons we’re featuring the project now. [Titan's] plan is to model this after the Bus Pirate interface. We think it’s a good idea since a lot of folks have already learned the syntax. We didn’t see a contact form on his site, but if you’re interested in contributing to the project you might want to leave a comment here or on his project page (linked above).