WeAct MSPM0G3507 is a BluePill-like development board equipped with Texas Instruments’ 80 MHz MSPM0G3507SRHBR Arm Cortex-M0+ mixed-signal MCU with 128KB flash and 32KB SRAM.
The board features a USB-C port for power and programming, two buttons for Reset and BSL (Bootstrap Loader), a 4-pin SWD port for debugging, and two 18-pin headers for GPIOs, CAN Bus, ADC, DAC, I2C, UART, and other interfaces. The MSPM0G350x microcontroller also comes with a math accelerator for DIV, SQRT, MAC, and TRIG computations which could prove useful for control control and signal processing.
WeAct MSPM0G3507 specifications:
- MCU – Texas Instruments MSPM0G3507 Arm Cortex-M0+ microcontroller at 80 MHz with 128KB flash, 32KB SRAM, 2x 4Msps ADC, DAC, 3x COMP, 2x OPA, CAN FD, MATHACL math accelerator
- USB – USB-C port for power and programming via CH340X USB to TTL chip
- Expansion – 2x 18-pin with power signals, I2C, SPI, GPIOs, ADC inputs, DAC, CAN Bus, etc…
- Debugging – 4-pin SWD connector
- Misc
- NRST and BSL/A18 buttons
- Blue user LED
- Power Supply – 5V via USB-C port; ME6231A33M3G 5V to 3.3V LDO
- Dimensions – 46.2 x 18.3 mm
WeAct Studio is well-known for making ultra-cheap boards with limited documentation. The WeAct MSPM0G3507 development board got the same treatment with the documentation hosted on GitHub only consisting of the PDF schematics, the MCU datasheet in English and Chinese, and a blink sample program. So most people will probably refer to the MSPM0G3507 LaunchPad development kit’s product page for software resources and documentation, or jump directly to the MSPM0 SDK documentation for getting started instructions and more code samples.
The MSPM0L and MSPM0G were introduced in 2023 as low-cost microcontrollers selling for as low as 39 cents in quantities and the aforementioned LaunchPad board goes for $16.99. But WeAct Studio’s board is much simpler and cheaper going for just $2.28 plus shipping on AliExpress.
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Isso amazing how cheap they can go.
We at Linuniz are currently adding Zephyr RTOS support for both G and L series, which will be mainlined soon. Work in progress tree is here: https://github.com/linumiz/zephyr/tree/dev/ti/mspm0
What’s the advantage of this compared to the other boards in their lineup?
And I was wondering if anyone in the community has any recommendations as to how to hook up this devboard into a reliable battery powered setup? (Where unlike USB-C your battery voltage slowly falls… and you need an RTC and an SD card reader)
> What’s the advantage of this compared to the other boards in their lineup?
The MSPM0 micros are for mixed-signal so they’re sorta like half way between a generic micros and a DSPs where they have a lot of analog peripherals like amps and comps along some math accelerators to handle sensor input and the likes.
The big disadvantage is the lack of connectivity peripherals. Like, they’ll speak i2c fine and have a CAN and AES encryption acceleration for industrial stuff… But not much else.
> And I was wondering if anyone in the community has any recommendations as to how to hook up this devboard into a reliable battery powered setup?
They’re the chips that are typically used for battery management system. Like, TI has a reference “MSPM0 Gauge Hardware Board” specifically meant to test batteries and teach EEs how to put together pulse charging protocols and the likes.
Thank you for!
Me and a buddy just tried to make a simple battery powered rain-gauge logger using a Liligo TTGO T-OI PLUS and we’ve had endless issues with power.
https://github.com/SWPhantom/Rainus
Probably ESP32 wasn’t the best match there and there were a lot of mysterious things that I can only attribute to power. It was supposed to be a simple project: Just an Arduino project that sleeps the board, wake up on button press, write down the date/time to an SD card file, go back to sleep till next button press. But it ended up not working consistently enough to be usable and the boards would die after a few months. The problems were never of one sort, but the most common was very weird readings on the LDO output pin (ie. often not getting a good 3.3V)
I was going to try switching to WeAct’s devboards with CH32V203 chips. They also have integrated RTCs. So that’d be one less component to worry about (b/c they were external on the TTGO boards) and a lower BOM. The only part that I’d need to worry about powerwise would have then been the SD card reader.. I guess that could be powered of this board’s 3V rain? which would be regulated by the LDO on this board?
So Battery to 5V rail, and then 3V to SDCard reader.. or maybe I’m being naiive?
Would I need anything between the battery and the board otherwise?
The ESP32-C3 doesn’t have a deep sleep state and Li-Ion isn’t really appropriate for the continuous low power draw you want for an RTC anyhow so I think that board is just not made for this.
I’m guessing you followed a suggestion to use an ESP32 (different series of Espressif SoCs using Xtensa LX6 and LX7 cores rather than RISC-V) since those have low power support and a lot of battery-powered projects use them?
Either way, if you don’t need wireless and all that compute, just power an ATtiny off a CR2032 along with a DS1307 and be done with it. I know RISC-V and ESP32 are all the rage with you whippersnappers (LOL) and I do think you could make an CH32V203 work… But, honestly, your use-case is quite literally what they’re made for and they have the educational docs doing nearly exactly what you want: http://ww1.microchip.com/downloads/en/AppNotes/AN2543-Temperature-Logger-with-ATtiny817-and-SD-Card-v2-00002543C.pdf
With that out of the way, here’s a CH32V203 powered by a CR2032 for reference: https://github.com/wagiminator/CH32V003-GameConsole
I guess my intention was to use an existing board instead of laying out and ordering my own – just so there is one less source of potential things going wrong. They’re also difficult to beat in terms of price and volume (if I get these cheap and reliable enough, I’m envisioning using a few dozen)
I’d ideally have this running for a year or 2 in remote study sites. They’re actually places in caves to monitor drip water – so my main enemy is the moisture/humidity. So that’s why I was initially avoiding coin cells. The Lions we used (18650) were a bit expensive and drained pretty fast, so we had to go in and replace the batteries regularly (but they can be recharged)
Well in all honesty the toolchains do make life a lot easier :)). The OG chips require weird custom compilers often bundled with IDEs. They will also have no ability to hook up to GDB and support very if any breakpoints. That’s I think a big part of why the STM32 chips were so popular.. I even managed to get it working with CMake and KDevelop a one point 🙂
In our case we stuck with Arduino – again so there is less room for issues
As the link shows, it’s the CH32V003, and that chip, while very popular and with good support, unfortunately doesn’t have an RTC built-in. The CH32V203 was their cheapest option with and RTC
That said, it doesn’t have a lot of dev boards. Ultimately I’d like to work off a very cheap dev board and add as few components as possible so that there is less room for things to go sideways :))
> I guess my intention was to use an existing board instead of laying out and ordering my own…
The DigiSpark ATtiny85 was an Arduino board and there’s still plenty of $2 clones of it over at aliexpress when looking for “ATtiny85”.
Running off a battery: https://www.instructables.com/Reducing-Battery-Power-Consumption-for-Digispark-A/
A youtube video using the DigiSpark to access an sdcard: https://www.youtube.com/watch?v=G28aswhK_Gw
Using the chip itself on a breadboard to read an sdcard: https://www.instructables.com/Attiny85-Sd-Wav-Player/
I think I saw discussions around about the circuitry to power it off an 18650 if the loss-aversion is too much to stomach. But I think there’s DIY USB power bank cases over at aliexpress using 18650 that sell for couple of bucks that you can just use as is to power it?
Regardless, ask in reddit or the arduino forums making sure to detail your 1-2year remote use case and see what they come up with. Maybe there’s more modern dev boards that provide a more complete solution for your specs. I don’t put together this sort of projects for living so there’s a good chance I’m missing something.
I really appreciate all your thoughts and feedback. It’s very helpful – and I’ll try to follow up on reddit
EDIT: The ATtiny85 solution is interesting. They have boards for less than 2USD on Taobao. Unfortunately they don’t come with an RTC and an external one generally costs more than the devboard :))
Well, keep in mind that other ESP32-C3 projects doing plant stuff also involve custom power delivery: https://www.cnx-software.com/2025/01/08/plant-bot-esp32-c3-soil-sensor-and-pump-driver-for-fully-automated-indoor-plant-care/
Now, of course, it’s a custom design with its own circuitry and is meant to run for about a week on a charge while also driving a motor for the pump… Still, it’s probably a good indication for the kind of use cases the micro is meant for.
Anyhow, it’s open source so it might be worth looking through to see if anything there could apply to your code base in reducing consumption and what not: https://github.com/tooyipjee/PlantBot
Still, those ESPs are fundamentally meant for bluetooth and wifi IoT stuff so I just can’t imagine them ever outliving an ATTiny design.
Is it possible for board makers to replace the likes of the CH340X with cheap MCUs like the CH32 series so that users could reflash it with something that delivers native USB host or the likes instead?
The BoM differences seem to be in cents but it will open up a lot of use cases for analog and DSP dev board like MIDI and virtual file systems.