“M5Stamp PLC Controller with M5StampS3” or just “M5Stack StamPLC” is a programmable logic controller (PLC) based on the StampS3A ESP32-S3 wireless module and offering 8 opto-isolated digital inputs, 4 relay outputs supporting both AC and DC loads, plus RS485 and CAN Bus interfaces.
The DIN Rail IoT controller also features a 1.14-inch color display, a RESET/BOOT button, 3 user buttons, and a buzzer or user interaction. The M5Stack StamPLC also integrates an LM75 temperature sensor and an INA226 voltage/current sensor, as well as a microSD card slot for data storage, and it can take a wide voltage input between 6 and 36V DC.
M5Stack StamPLC specfications:
- Control Module – StampS3A (similar to M5Stamp S3)
- SoC – Espressif Systems ESP32-S3FN8
- CPU – Dual-core 32-bit Xtensa LX7 microcontroller with AI vector instructions up to 240MHz, RISC-V ULP co-processor
- Memory – 512KB SRAM
- Storage- 8MB flash
- Wireless – 2.4GHz WiFi 4 (802.11b/g/n), Bluetooth 5.0 BLE + Mesh,
- 2.4GHz 3D antenna
- USB – 1x USB Type-C port
- Expansion connectors for I/Os such as SPI, I2C, UART, ADC, and more
- SoC – Espressif Systems ESP32-S3FN8
- Storage – MicroSD card slot
- Display – 1.14-inch color display with 240 x 135 resolution (ST7789v2 controller)
- Digital Inputs – 8x opto-isolated digital inputs, Input voltage range: DC 5~36V
- Digital Outputs – 4x relay outputs
- AC – 5A @ 250V
- DC – 5A @ 28V
- Communication Interfaces
- PWR-CAN for CAN Bus
- PWR-485 for RS485
- Sensors
- LM75 temperature sensor
- INA226 voltage/current sensor
- Expansion Interfaces
- 16-pin GPIO.EXT interface; maximum load: 4.76V @ 700mA
- 2x 4-pin Grove interfaces; maximum load: 4.81V @ 700mA
- Misc
- RESET/BOOT button, 3x user buttons
- Buzzer
- RX8130CE RTC chip
- Power Supply – 6 to 36V DC @ 1A via 5.5×2.1mm power barrel jack (center positive)
- Power Consumption
- Standby – 21.60mA @ 5V , 15.22mA @ 12V
- Operation – 93.89mA @ 5V, 47.84mA @ 12V
- Dimensions – 80 x 72 x 33.4mm
- Weight – 139.4 grams
- Temperature Range – 0 to 40°C
The StamPLC ships with four “mounting accessories” and four screw clip fasteners. It’s preloaded with firmware that automatically uploads data to M5Stack’s EZDATA cloud platform with a dashboard and remote cloud access and control.
If you’d rather roll your own firmware, the company mentions the UIFlow 2.0 visual programming platform, the Arduino IDE, and the ESP-IDF framework are supported. More hardware details, as well as instructions and code samples for Arduino and ESP-IDF are provided on the documentation website, but UIFlow 2.0 examples are only shown as “coming soon”, although the video embedded at the end of this article shows a demo with UIFlow 2.0… You’ll also find instructions to get started with the EZdata cloud platform there.
M5Stack says the StamPLC is suitable for industrial automation and remote control, distributed control systems, smart energy management, and smart manufacturing. It’s not quite the first ESP32-based PLC in the market with alternatives including Industrial Shields ESP32 PLC 14, Seeed Studio EdgeBox-ESP-100 (also based on ESP32-S3), and NORVII IIoT industrial controller among several others.
The StamPLC sells for $42.90 on AliExpres or the M5Stack shop,
Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.
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Looks more like a toy, where do the Legos attach?
A PLC without Modbus is rare too lol
If you want to roll your own firmware, and hard realtime is not a requirement, then ESPHome should work just fine on this hardware, and includes modbus TCP support for connecting to supervising systems.
Why should it not do modbus? It has an RS485 interface, what else does modbus need?
The protocol stack?
I asked them that too – no answer 🙂