Overview
An IoT node or a consumer device must be cheap, small and often battery-powered, and the microcontroller and the flash set the cost and the power. GigaDevice's GD32 microcontrollers cover the range from the low-power Cortex-M23 to the mainstream Cortex-M3, and the GD25 serial NOR Flash stores the firmware in a small package. BeiLuo supplies both with genuine traceability and FAE support. This page shows how they fit together in an IoT and consumer design.
Choosing the Core for Cost and Power
The core is chosen from the workload and the power budget. The Cortex-M23 GD32E230 is a modern, low-power, low-cost core with a good code density, which suits a simple sensor or control node that spends most of its time asleep. The Cortex-M3 GD32F103 adds memory and interfaces such as CAN and USB, which suits a richer device or a small gateway. Both use the familiar Arm toolchain, so the code and the skills carry across, and the choice is a matter of cost, power and the peripheral set.
Low-Power Design
For a battery node the low-power design matters as much as the core. Use the sleep, the stop and the standby modes of the MCU, keep the duty cycle low and turn off the unused peripherals and the external parts between measurements. Choose a serial NOR Flash with a low stand-by and deep-power-down current, and consider whether the code can run from the flash in place rather than from RAM, which saves the RAM and its leakage.
Memory and Code Storage
The firmware, the settings and the calibration are stored in a GigaDevice GD25 serial NOR Flash, which the MCU reads in place at boot. The small SOP8 package and the few SPI pins keep the board simple, and the 4 MB, 8 MB and 16 MB options let the density grow without a board change. The low stand-by current of the flash suits a battery design, and the write protection keeps the settings safe.
Boot and Update
The MCU boots from the flash and, where the design supports it, updates the firmware over the air by writing a new image to an unused sector and switching the boot pointer. Plan the update scheme and the power-loss safety early, because a failed update can brick a device. The security registers and the unique ID support a signed image.
Interface and Connectivity
A consumer or an IoT device needs interfaces for its sensor, its display, its storage and its network. The GD32 peripherals include SPI, I2C, USART and I2S, an ADC and a comparator, and a set of timers for a PWM output and a pulse measurement. For wireless connectivity the MCU drives a radio or a module over SPI or UART, and the protocol stack runs on the core. Confirm the interface count against the design before you commit.
Time to Prototype
Because the core is a standard Arm Cortex-M and the toolchain and the firmware library are available, a working prototype is quick to reach. Start from the library, use a common package such as the LQFP-48 for the first build and move to the production package later, and prototype the flash and the MCU together so the boot path is proven early.
Cost and Availability
For a consumer product the cost and the availability drive the choice as much as the performance. GigaDevice offers a competitive price across the GD32 range, and the GD25 flash is a low-cost, widely available boot device, so the two together keep the bill of materials low. BeiLuo holds the mainstream models in stock so a design can move to production without a delay.
Getting Help
Send your sensor and interface list, your power budget and your cost target to our FAE team and we will propose an MCU and a flash, help with the low-power design and the update scheme and review the layout. BeiLuo holds mainstream GD32 MCUs and GD25 flash in regional stock and ships them with an import declaration, a certificate of origin and a RoHS compliance file, so an IoT or consumer design can move from prototype to production without a supply gap.