We’re all familiar with the wide variety of Arduino development boards available these days, and we see project after project wired up on a Nano or an Uno. Not that there’s anything wrong with that, of course, but there comes a point where some hobbyists want to move beyond plugging wires into header sockets and build the microcontroller right into their project. That’s when one generally learns that development boards do a lot more than break the microcontroller lines out to headers, and that rolling your own design means including all that supporting circuitry.
To make that transition easier, [Sean Hodgins] has come up with a simple Arduino-compatible module that can be soldered right to a PCB. Dubbed the “HCC Mod” for the plated half-circle castellations that allows for easy soldering, the module is based on the Atmel SAMD21 microcontroller. With 16 GPIO lines, six ADCs, an onboard 3.3 V regulator, and a reset button, the module has everything needed to get started — just design a PCB with the right pad layout, solder it on, and surround it with your circuitry. Programming is done in the familiar Arduino IDE so you can get up and running quickly. [Sean] has a Kickstarter going for the modules, but he’s also releasing it as open source so you’re free to solder up your own like he does in the video below.
It’s certainly not the first dev module that can be directly soldered to a PCB, but we like the design and can see how it would simplify designs. [Sean] as shown us a lot of builds before, like this army of neural net robots, so he’ll no doubt put these modules to good use.
I like the idea. SAMD21 is a really nice uC and good next step after ATmega328. What I can’t understand though is why there is so little cheap boards with this chip. Adafruit uses them a lot, but on Aliexpress you can find only two models. Why is that? Price? Availability?
Try searching for stm32f103c8t6 and you’ll see why. It’s a Coretex M3 with 128KB of flash and 20KB of RAM, and you get a board with a RTC, lots of GPIO, and 12mbps USB for < $2. For those that aren't ready to give up their Arduino training wheels, you can get an Arduino core port at stm32duino.
Do you have a link to that board I can only find one for $12, I can see some that have pins for an esp8266 which look pretty swanky.
I just did a search and found many of them ie https://www.aliexpress.com/item/STM32F103C8T6-ARM-STM32-Minimum-System-Development-Board-Module/32656048071.html (less than $2US)
or all 800 found in the search https://www.aliexpress.com/w/wholesale-stm32f103c8t6.html
You can buy lots of 10pcs for $5 on ebay
Are there castigated versions of the stm32 modules that can be used in the same way as the one in the post, ie SMD to your own carrier board?
I know this is late, but in case somebody finds this later: there aren’t ready-made ones as far as I know, but you can always use the stm32f103 in a project at home by using one of these castellated boards: https://oshpark.com/profiles/coddingtonbear
thanks!
Great concept, and almost a no-brainer for battery-powered Arduino projects… But at around US$20 a piece… it’s not yet a must-have for this hobbyist. I still have a drawer-full of $3 Nano knockoffs and ESP8266s, and some PICs for 8-bit fun.
I wish them success with the kickstarter, but I hope to see this thing get below $10.
Thanks!
After what I have to pay for shipping from up here in Canada(as the shipping is included in the Kickstarter cost), they are priced around $13US per module. I would love to get them below $10US, but its too risky at this quantity.
Planning on doing a series of different microcontrollers and sensors/power modules.
I like the idea, but if you aren’t going to be using the low power features, I’m not sure it’s all that much better than an ESP32 WROOM. You need to bring your own reset button, capacitors, and pull resistors, but you get a lot more power and WiFi for the cost.
That’s one thing I really like about the PIC chips. You don’t need anything except once capacitor really. It’s a shame Arduino IDE doesn’t do PIC and AVR bare chips usually don’t come in SOIC. I’d love a reduced pin count atmega32u4 in SOIC.
Is it just me?
I’ve already moved from a through-hole Boarduino to an ATtiny85 PDIP on perfboard to a bare LQFP32 STM8 on my own PCB with 0603 passives, so I suppose this type of product should appeal to me, but I just don’t see the attraction. If I’m going to design my own PCB, I’d rather design it for the actual µC and its supporting components that futz around with a castellated module.
The one exception would be for wireless designs, like the ESP-12F, where installing as a module eases some of the regulatory burden. That’s not the case here, though.
Is this still a market due to lingering fear of handling SMDs, and a perceived simplicity of hand-soldering through-hole and castellated pads rather than re-flowing SMD parts? I’ve bought a hot air rework station and embraced SMD now, and have to say I prefer it to through-hole in several ways. If you’re learning to design your own PCBs, learn how to re-flow too; it opens a whole new world of low-cost parts.
All that aside, it’s great to see the SAMD21 being promoted and its use streamlined. For those that would rather build systems with bigger modules than bare components, this may be just what they need. Best of luck!
Hey HaD, Thanks for the post!
Ill self plug my Kickstarter here in case anyone is interested: https://www.kickstarter.com/projects/idlehandsdev/hcc-mod-ready-to-solder-arduino-module
As the Kickstarter goes on I’m releasing open source projects that will use the module to show people what they can make. The first one was a mechanical keyswitch macro Keypad. Here is the video for that: https://youtu.be/bd1iaVNwYvI
Stay tuned!
For prototyping, look at what Digi did with the castellation connections. Sort of like PLCC for the 21st century.
STM32 lead times will kill commercial projects, specially the L series.
This makes a lot of sense if you do lots of prototyping and don’t want to spend a lot of time repeating circuitry for the micro controller. Its like a programming function.
If you’re already designing a board, isn’t it fairly easy to design the board to just use the chips and components? This could definetely be useful for for small batch projects where you want to save a bit of time or want to hand solder your components.
Nice idea and I headed to kickstarter to pledge, however import tax and processing fees put the cost up to £45 for the two boards (77 CA$) – I just cant justify that amount.
I was just searching for something like this. Don’t like to put headers on my project. And I don’t want to be bothered with all components for a micro controller.
Great project. I just kickstarted the project