STM32H747 MicroMod

Hello everyone,
I am new to this community. I recently discovered the MicroMod ecosystem and seems like a nice idea.
However, I have seen that it lacks some serious computing power. So I have decided to create a MicroMod, packing an STM32H747 with 16MB SDRAM and 16MB external Flash and full blown Bluetooth and WiFi capabilities.

I am making this post to see if there is interest in this contraption and if there are other functionalities that I missed, so let me know what you think about this.

It has most of the interfaces specified in the MicroMod documentation, however it has only one USB 2.0(480Mbps) and SDIO can not be configured as SPI(limitation of the STM32 pinout.
On the plus side, it has 166MHz SDRAM(16bit data bus), 56Mbps WiFi(LBEE5KL1YN) and a dedicated 2 lane DSI interface(up to 10Gbps bandwidth).

To keep the cost somewhat low, The board size was increased to 23x27mm, but it is fully compatible with MicroMod socket.

It is still work in progress, but here is an early preview:

Very cool! I might buy one from ya :slight_smile:

Update this thread with your progress!

Hello again, coming back with updates.

I have decided to switch to STM32H757 MCU. It is slightly more expensive, but the added security justifies the small added cost.

In another order, below is the M.2 edge pinout. In the center, the MicroMod standard pinout is shown and on the outsides are the assigned peripherals.

Thank you for the interest and I will keep you posted with the updates as I go!

Below is a block diagram, showing the main blocks in the module and how they are connected. In order to simplify the diagram, the M.2 edge connector is not shown.

Coming back with some estimate prices. I am preparing a crowdfunding campaign to start the production of the first batch. Still work in progress, but here are some tiers:

Bare modules:

  • 50x Super Early Bird: $59
  • 50x Early Bird: $69
  • Retail price: $79
  • Retail pack(3x): $219
  • Mega pack(10x): $699

Kits:

  • 50x Early Developer(CarrierBoard + module + antenna + USB Cable): $99
  • 20x Early Dev Team(2x CarrierBoard + 5x module + 2x antenna + 2x USB Cable): $349
  • Developer(CarrierBoard + module + antenna + USB Cable): $119
  • Dev Team(2x CarrierBoard + 5x module + 2x antenna + 2x USB Cable): $449

I would appreciate any feedback regarding the pricing and the functions. I am still wrapping my head around what is available out there and try to place myself in this competitive market. If you have any ideas for kits, just let me know.

The Story Behind the Module: From a Birthday Gift to a MicroMod Powerhouse

Hey everyone, a few people were curious about the backstory of this project, so I wanted to share how it all came to be. It’s been a two-year journey of learning, problem-solving, and a bit of a happy accident.

The Spark: An Arduino Giga and a Big Idea

It all started about two years ago when I received an Arduino Giga for my birthday. My prior experience was mostly with simple 8-bit MCUs, so diving into something this complex was a huge step up. But I was committed to learning.

Fast forward about a year, and I was deep into a personal project: a device to read and write data from common buses like UART, I2C, SPI, CAN, RS-485, and RS-232. The Giga was perfect for initial development.

The First Big Challenge: The Dreaded BGA

Soon, I needed dedicated hardware. This wasn’t a problem, until I realized the STM32 chip’s BGA package forced me into a big expensive 6-layer PCB just to properly fan out all the connections. I started analyzing the possibility of modular design. This would reduce the cost for this project and also develop a module easy to integrate in future projects.

To bring the cost down, I decided to create a small M.2 module with the BGA chip. This would allow the main PCB to be a much cheaper 4-layer board. The plan worked—it cut my prototype costs by about 30%!

I kept working on the code in my free time, learning proper software architecture along the way.

The “Aha!” Moment: Discovering MicroMod


Image from the SparkFun website

Then, about two months ago, everything changed. I was browsing the web when an ad for a SparkFun MicroMod module popped up. The promise of a standardized ecosystem, compatibility with many carrier boards, and a tiny 22x22mm footprint immediately caught my attention.

After a few hours of reading the documentation, I was sold. I knew I had to completely revamp my module.

A New Vision: Going All-In on MicroMod

I decided to pivot my design and make it a no-compromise MicroMod module. My goals were:

  • Full Compatibility: I switched from an M-key to an E-key M.2 connector and redesigned the pinout to be fully MicroMod compatible .

  • Powerful Features: I wanted to pack in features that I, as a developer, would want. This meant:

    • Improve Wireless Connectivity: A Murata Wi-Fi + Bluetooth LE module was a must.

    • Add Memory: I added 16MB of external SDRAM to enable complex IoT tasks and even run Edge AI applications.

    • Integrated Sensing: Since there was space, why not? I integrated a full suite of ST sensors:

      • A 6-axis IMU and an eCompass for navigation.

      • Temperature and Pressure sensors for environmental data.

One of the most exciting parts is the sensor integration. The IMU and eCompass are configured so the IMU can directly sample the eCompass and perform sensor fusion internally. According to ST, this should allow it to output true 9DoF quaternions right from the hardware—a feature I can’t wait to test!

And that’s how we got here. It started as a cost-saving measure and evolved into a powerful, feature-packed compute module for an ecosystem I’m incredibly excited to be a part of.

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