CH32V307V-EVT-R1 is a development board based on WCH CH32V307 RISC-V microcontroller with an Ethernet port, an USB Type-C port, and eight UART interfaces accessible through headers.

As we noted in our article about CH583 Bluetooth 5.3 RISC-V microcontroller, WCH (Jiangsu Qin Heng) has started to share resources like datasheets and code samples through Github. They’ve done the same again for CH32V307 with schematics (PDF only), a datasheet in English, and firmware either bare metal or based on RT-Thread OS to control the eight serial interfaces over Ethernet.

Let’s check CH32V305 and CH32V307 MCU specifications first:

MCU core – WCH designed RISC-V4F 32-bit RISC-V core up to 144MHz FPU – Single-cycle multiplication and hardware division, hardware float point unit (FPU) ; Memory – Up to 64KB SRAM Storage – Up to 256KB Flash Networking – Gigabit Ethernet MAC, 10 Mbps PHY USB – 1x USB 2.0 OTG full-speed interface, 1x USB 2.0 host/device interface with built-in 480 Mbps PHY Serial 8x USART interfaces including 5x UARTs 2x CAN interfaces (2.0B active) 2-wire debug interface Other interfaces/peripherals SDIO interface FSMC memory interface DVP digital video interface 80x GPIO ports, with 16 external interrupts; 2x I2C, 3x SPI 2x I1S 2x 12-bit DAC; 2-unit 16-channel 12-bit ADC, 16-channel TouchKey; 10 timers; 2x general DMA controllers, 18 channels in total; 4x amplifiers; Security – Single true random number generator (TRNG), CRC calculation unit, 96-bit unique chip ID; Power management Supply voltage – 2.5V/3.3V, GPIO unit is supplied independently; Low-power modes: sleep/stop/standby; Power-on/power-down reset (POR/PDR), programmable voltage detector (PVD); Packages: LQFP64M, LQFP100. CH305 and CH307 are pretty similar, except CH305 has less memory (32KB SRAM) and storage (128KB flash), and lacks interfaces like Ethernet and DVP.

CH32V307V-EVT-R1 board specifications:

MCU – WCH CH32V307VCT6 32-bit RISC-V microcontroller @ 144 MHz as described above

Networking – 10 Mbps Ethernet

USB – 1x USB 2.0 Type-C port (480 Mbps), 1x USB 2.0 Type-C port (Full Speed: 12 Mbps)

Expansion

MCU I/O expansion headers with 8x UART interfaces, and more

Arduino headers

Debugging

SDI & UART header to download and debug CH32V307 firmware

USB-C port to connect to WCH-Link (selectable by jumper)

Misc – LEDs, Reset button, user button,

Power Supply

Switch to select USB or external 5V power supply

5V to 3.3V voltage regulator

All resources can be found ch32v307 Github repo, with source and PDF schematics & PCB layout, datasheet, board’s user manual, code samples for each peripheral, and two samples to use the board as an Ethernet to multiple UARTs device as follows:

RT-Thread/uart_server_rtt – 8 UARTs server demo based on RT_Thread, LwIP. bart_metal/8_uart_server – 8x UARTs server demo based on WCH_NET_lib without any OS (bare metal) Patrick Yang, Technical director at WCH, says they’ve only implemented part of the code so far, and also welcome contributions from the community: