Building multifunctional yet safe IoT devices can be complicated by the need to use external network adapters and multiple (often not entirely compatible) libraries. The W55RP20 chip from WIZnet solves these problems in a way that is accessible to designers and constructors.
Below we present two WIZnet solutions. The first is a System-in-Package combining the functionality of a Raspberry Pi RP2040 microcontroller with an Ethernet network adapter (W5500). The second product offered is a development module based on this chip containing all the elements necessary to launch a fully functional IoT platform (Internet of Things). Both products are available from TME, directly from our warehouses.
In this article, we cover topics such as:
- Functionality based on the popular RP2040 chip
- Network protocols supported by the W5500 adapter
- Ease of implementation of W55RP20 and specifications
- Learning and prototyping using the development module
- Industrial IoT devices adapted to Ethernet networks
Components of the W55RP20 system
The W55RP20 chip is placed in an SMD package measuring just 8x8mm.
The W55RP20 in a single QFN68 package contains a fully functional microcontroller and a network adapter with hardware support for the TCP/IP stack. The basis for this solution is the RP2040, a chip from Raspberry Pi (known from the Pi Pico board), designed with easy implementation and versatility in mind. It can be programmed using C/C++, MicroPython, CircuitPython, FreeRTOS, or Arduino. Its key features are listed below.
- Dual-core processor with Arm Cortex-M0+ architecture clocked at 133MHz.
- 12-channel DMA controller (Direct Memory Access) allowing for fast data transfer to peripherals, thus enabling multimedia projects, low-latency drivers, etc.
- A wide selection of interfaces: 2 x UART, 2 x SPI (one channel used for communication with the network controller), 2 x I2C, 1 x USB 1.1 (in host or device mode).
- 2 PIO blocks (Programmable Input/Output), each with 4 state machines, allowing for generating signals with very precise frequencies, emulating interfaces, implementing custom transmission methods.
- 23 GPIO pins with varied functionality, including outputs for 16 PWM generators and inputs for 4 A/D converters.
Capabilities of the W5500 controller
Inside the chip, the RP2040 microcontroller is connected via an SPI interface to WIZnet’s proprietary network controller: W5500. Its main task is the hardware handling of the Ethernet interface and the TCP/IP stack. It should be noted that as a whole, the W55RP20 can support a range of network protocols TCP, UDP, ICMP, IGMP, ARP, PPPoE, and also offers support for AWS, Azure, TLS, SSL, MQTT, and HTTP. The W5500 controller offloads the microcontroller cores, ensuring stable network communication, allowing the computational power of the RP2040 to be fully utilized for controlling the target device.
Additional data about the chip
A significant feature of the W55RP20 is that it can be used and programmed almost identically to the RP2040 microcontroller. In addition to the structures mentioned, the chip includes 2MB of Flash memory. It can be powered by DC voltages ranging from 1.8V to 3.3V DC. The chip operates at temperatures from -40°C to 85°C.
Development module W55RP20-EVB-PICO
The board features a USB C connector for power and programming the chip.
For prototyping and testing projects that are ultimately to use the W55RP20 chip, the manufacturer has prepared a development module, which contains all the elements necessary for its operation, including a DC/DC voltage regulator, control LEDs, and RJ45 and USB C sockets. The latter is used to connect to a computer and program the microcontroller, as well as update the firmware and power the board (voltage range from 1.8V to 5.5V). There is also the possibility to solder on it an adapter for PoE (Power over Ethernet), which allows powering the entire module through network infrastructure.
Working with the W55RP20 module is very simple, especially for users with even minimal experience with the RP2040. It is worth noting that the PCB pinouts are identical to the Raspberry Pi Pico, the most popular board implementing the British manufacturer’s microcontroller. The RJ45 connector supports automatic negotiation (Full/Half Duplex, 10/100Mb/s).
To further facilitate work, two buttons are placed on the circuit: reset and a bootloader selection/loading switch.
Applications and summary
The presented chip and development module are multifunctional platforms, which can easily be made the foundation of various network devices. Applications for them can be easily found by both hobbyists and professional designers involved in building circuits for consumer use (field smart home) and industrial.
The well-documented and popular RP2040 microcontrollers are already often used in automation and robotics controllers, especially those made according to individual customer specifications. Coupling the microcontroller with the W5500 adapter further expands its capabilities, allowing for remote monitoring and control of devices, also via the cloud or the Internet. Wired connectivity proves effective even in the presence of relatively strong electromagnetic interference (an inevitable phenomenon in machine parks), where the use of WiFi and similar technologies would be suboptimal.
