Hardware and Design
The Cardputer-Adv is an enhanced iteration of the small-form-factor computer powered by the Espressif ESP32-S3 microcontroller. In essence, the Cardputer-Adv is a slightly redesigned version of the original. Side-by-side, they differ visually only in color—the new model is white, while the previous was light gray. The shape, design, and general purpose remain identical. The "brain" of the system is still a Stamp series development board, but upgraded to the Stamp-S3A. Compared to the Stamp-S3 found in the predecessor, the "A" revision features a redesigned 3D antenna for improved connectivity and a "softer," more responsive Reset button. Note that this button is covered by a sticker, making it somewhat awkward to press. Other changes include internal LED wiring and lower power consumption. The core remains the ESP32-S3FN8 microcontroller with 8MB of Flash and 23 GPIO pins. As we have covered the ESP32-S3 extensively in previous articles, we will not repeat those technical details here. The USB-C port is used for programming the Stamp, power delivery, and charging the integrated battery.
Display, Keyboard, and Audio
The Stamp-S3A connects to the motherboard via two header rows and interfaces with the display via an FPC connector. The screen is the same color IPS LCD used previously (ST7789V2, 240×135 resolution, 1.14 inches). A defining feature of this computer is its 4×14 (56 keys) QWERTY keyboard. The keys are significantly improved with a different tactile feel (260gf vs. 160gf actuation force). Many keys serve dual purposes via 'Fn', 'Aa', 'Ctrl', 'Opt', and 'Alt' modifiers. Keyboard scanning is now handled by the TCA8418 integrated circuit.
The audio subsystem has undergone significant changes. The ES8311 codec replaces the previous NS4168 and SPM1423 combination, resulting in superior microphone noise reduction. Combined with the NS4150B amplifier and a 1W speaker (located standardly beneath the Stamp), the output quality is markedly better. Furthermore, the Cardputer-Adv now includes a 3.5mm audio jack on the side for headphone connectivity.
Power and Connectivity
The Cardputer-Adv can be powered via USB-C or the internal battery. This version replaces the two smaller cells of the original with a single, larger 1750mAh battery, managed by the TP4057 charging IC. Like its predecessor, the Cardputer-Adv features a GROVE port (supporting I2C and 5V). A small adjacent switch allows the user to toggle the 5V line direction: the Cardputer can either power an external sensor or be powered by an external source.
While the original Cardputer relied solely on the GROVE port for expansion, the Cardputer-Adv introduces an additional 2×7-pin header (UART, I2C, SPI) on the rear for connecting peripheral devices. M5Stack continues to use the GROVE connector for its extensive ecosystem of "Unit" expansion modules.
Sensors and Modules
New features include the BMI270 six-axis motion sensor (IMU). The device retains the physical power switch, 'Boot' and 'Reset' buttons, an infrared (IR) LED, and a Micro-SD slot. Examining the PCB reveals a layout largely identical to the original; it even retains an unpopulated JST connector for a smaller battery. Interestingly, there is an unconnected FPC connector near the 3.5mm jack for which we found no official documentation. The Cardputer-Adv maintains its Lego-compatible mounting holes (though there is one row fewer on the back) and internal magnets, allowing it to be mounted on metal surfaces like a refrigerator door.
Along with the Cardputer-Adv, we received the CAP LoRa868 (now the updated version is Cap LoRa-1262) expansion module, designed to interface via the 2×7-pin header. The CAP module features a matching plastic enclosure and contains two primary components: an 868MHz LoRa module (based on the SX1262 chip) with an SMA connector for an external antenna, and an AT6668-based GNSS module supporting GPS, Beidou (BD2/BD3), GLONASS, Galileo, and QZSS.
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Software and Programming
The Cardputer-Adv can be programmed using Arduino IDE, ESP-IDF, PlatformIO, or the manufacturer-recommended UiFlow2. UiFlow2 is a block-based visual programming environment, making it an excellent educational tool for introducing children to microcontrollers and electronics. The interface offers "Blocks," "Split," and "Python" views. In "Split" mode, users can see how dragging blocks generates real-time Python code—a bridge that helps beginners transition to text-based programming. To use this online tool, the UiFlow2 firmware must first be flashed onto the device using the M5Burner utility.
Several pre-configured examples are available via M5Burner, including community-driven projects. One highlight is Meshtastic for Cardputer-Adv, which integrates seamlessly with the Meshtastic mobile app for LoRa-based mesh networking and precise GPS mapping. The firmware provides a comprehensive menu for managing hardware segments like LoRa, GPS, and system time.
Conclusion
Additional examples include M5Launcher, which allows users to execute BIN files directly from the Micro-SD card. The factory demo provides a comprehensive hardware test. For those using the Arduino environment, extensive support is available via M5Stack libraries.
The Cardputer-Adv is exactly what its name suggests: a sophisticated, credit-card-sized computer with meaningful upgrades over the original. The CAP expansion module (e.g., Cap LoRa-1262) is a powerful addition, and the new 2×7-pin header opens endless possibilities for hardware hackers.
Source: SK LABS
Author: Dejan Petrovic