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STMicroelectronics SPWF01SA.21
- Part No.:
- SPWF01SA.21
- Manufacturer:
- STMicroelectronics
- Category:
- RF Transceiver Modules and Modems
- Package:
- Module
- Datasheet:
-
SPWF01SA.21.pdf
- Description:
- RF TXRX MODULE WIFI CHIP SMD
- Quantity:
- Payment:
- Shipping:
Inventory:3,528
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Product details
Overview
SPWF01SA.21 from STMicroelectronics is a certified 802.11b/g/n Wi-Fi module with integrated TCP/IP stack, AT command interface, and embedded HTTP server/client functionality. It supports infrastructure and soft-AP modes, operates at 2.4 GHz, features UART host interface, and delivers up to +18 dBm transmit power with -95 dBm receive sensitivity. It is used in industrial IoT gateways for secure OTA firmware updates and remote device configuration.
For engineers reviewing the SPWF01SA.21 datasheet, SPWF01SA.21 pinout, SPWF01SA.21 application, or SPWF01SA.21 equivalent, key selection considerations include its pre-certified 2.4 GHz RF performance, AT-based full-stack firmware (v3.5+), GPIO-controlled ADC/DAC/PWM peripherals, TLS 1.2 support via AT+S.TLSCERT, and external Flash-based HTTP filesystem management.
Technical Context
The SPWF01SA.21 integrates an ARM Cortex-M4F MCU running ST's "AT full stack" firmware, enabling standalone Wi-Fi connectivity without host-side protocol stack implementation. It implements IEEE 802.11n (20 MHz bandwidth), WPA/WPA2-PSK security, and TLS 1.2 handshake with certificate validation via AT+S.TLSCERT and AT+S.TLSDOMAIN.
It provides dual-mode operation: as a Wi-Fi client connecting to infrastructure APs or as a mini-AP serving up to 4 clients. Its UART interface supports configurable baud rates (default 115200), hardware flow control, and asynchronous WIND indications for event-driven host interaction.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Wi-Fi Standard | IEEE 802.11b/g/n (2.4 GHz ISM band, 20 MHz channel width) |
| Transmit Power | +18 dBm maximum - ensures robust link budget in noisy industrial environments |
| Receiver Sensitivity | –95 dBm at 1 Mbps (BPSK) - enables reliable low-SNR operation |
| Firmware Stack | "AT full stack" v3.5+ - includes TCP/UDP, HTTP(S) client/server, TLS 1.2, and file system |
| Host Interface | UART (3.3 V logic, default 115200 bps, RTS/CTS optional) - simplifies integration with STM32/other MCUs |
| GPIO Peripherals | ADC on GPIO8 (12-bit), DAC on GPIO15, PWM on GPIO1 - enables local sensor interfacing and actuator control |
| Certifications | FCC/IC/CE/TELEC - eliminates RF compliance burden for end equipment |
Pinout & Package
SPWF01SA.21 uses a 22-pin LGA package (13.5 mm × 11.7 mm × 2.0 mm) with 0.65 mm pitch, optimized for compact PCB layout and automated assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD | Power supply input | 3.3 V ±5 % main supply; requires local 10 µF + 100 nF decoupling |
| GND | Ground reference | Dedicated RF and digital ground pins - must be connected to common low-impedance plane |
| UART_TX | Transmit data output | 3.3 V CMOS output driving host RX; open-drain capable with pull-up |
| UART_RX | Receive data input | 3.3 V tolerant input; accepts 0–3.3 V logic levels from host TX |
| GPIO0 | Factory reset control | High at power-up triggers hardware factory reset of NV settings |
| GPIO1 | PWM output | Configurable frequency/duty cycle via AT+S.PWM - drives LEDs or low-power actuators |
| GPIO8 | ADC input | 12-bit analog input (0–3.3 V range); read via AT+S.ADC - monitors sensors or supply rails |
| GPIO15 | DAC output | Configurable voltage output (0–3.3 V); enabled via AT+S.DAC - drives analog interfaces |
Key Features
| Feature | Design Value |
|---|---|
| Pre-certified Wi-Fi radio | FCC/IC/CE/TELEC approval included - reduces time-to-market by >12 weeks |
| Embedded HTTP server | Static file system stored in external SPI Flash; managed via AT+S.HTTPDFSWRITE/AT+S.HTTPDFSERASE |
| TLS 1.2 support | Full certificate chain handling (CA, cert, key) and domain verification via AT+S.TLSDOMAIN - enables secure cloud onboarding |
| OTA firmware update | Atomic update via AT+S.FWUPDATE over HTTP(S) - preserves settings and avoids bricking |
| Low-power operation | Four power states (Active, Power Save, Sleep, Standby) controlled via AT+CFUN - extends battery life in portable devices |
Applications
| Industrial Sensor Gateway | Smart Building Controller |
|---|---|
|
Use Scenario: Aggregates Modbus RTU sensor data and forwards to cloud via HTTPS. IC Role / Device Role / Timing Role: Wi-Fi network interface and TLS-secured HTTP client endpoint. Use Value: Eliminates need for external TCP/IP stack or crypto offload; AT+S.HTTPPOST handles payload encryption and certificate validation. |
Use Scenario: Controls HVAC actuators and reports occupancy via BLE-to-Wi-Fi bridge. IC Role / Device Role / Timing Role: Soft-AP serving BLE gateway and infrastructure client uploading telemetry. Use Value: Dual-mode operation enables local commissioning (via mini-AP) and remote monitoring (via infrastructure mode) without host MCU intervention. |
| Connected Medical Device | Asset Tracking Module |
|
Use Scenario: Transmits ECG waveform snapshots to HIPAA-compliant cloud storage. IC Role / Device Role / Timing Role: Secure TLS 1.2 client with certificate pinning and time-synchronized uploads. Use Value: AT+S.SETTIME syncs RTC to NTP-equivalent source; AT+S.TLSDOMAIN enforces exact hostname match - satisfies audit requirements. |
Use Scenario: Logs GPS coordinates and sends periodic location reports over cellular fallback. IC Role / Device Role / Timing Role: Low-power Wi-Fi scanner (AT+S.SCAN) for indoor positioning and beacon detection. Use Value: Passive scan mode (AT+S.SCAN=p) consumes <5 mA average current; peer table (AT+S.PEERS) identifies nearby BLE beacons for trilateration. |
Availability
SPWF01SA.21 is available at Aetrix Electronics and suitable for industrial IoT gateways, smart building controllers, connected medical devices, and asset tracking modules requiring stable component supply, long-term lifecycle assurance, and pre-certified RF performance.
Supply support for SPWF01SA.21 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, sensors, power ICs, and wireless solutions for industrial, automotive, and consumer markets.
The SPWF01Sx series was developed to deliver production-ready, regulatory-certified Wi-Fi connectivity for resource-constrained embedded systems - enabling rapid deployment of secure, cloud-connected edge devices without RF or protocol stack expertise.
FAQ
What host processor interfaces does SPWF01SA.21 support?
SPWF01SA.21 communicates exclusively via UART (3.3 V logic) with configurable baud rate, hardware flow control (RTS/CTS), and software handshaking. It does not support SPI, I²C, or SDIO interfaces. The AT command set abstracts all Wi-Fi and TCP/IP operations, allowing integration with any microcontroller or host processor that provides a UART peripheral.
How is secure firmware update implemented?
Firmware updates are performed using the AT+S.FWUPDATE command, which downloads a signed binary image over HTTPS from a specified URL. The module validates the image signature before flashing, and the update process is atomic - if interrupted, it reverts to the prior working firmware. This requires prior provisioning of CA certificates via AT+S.TLSCERT and domain validation via AT+S.TLSDOMAIN.
Can SPWF01SA.21 operate as both client and access point simultaneously?
No. SPWF01SA.21 supports either infrastructure mode (client connecting to an AP) or soft-AP mode (hosting up to 4 clients), but not concurrent dual-role operation. Mode switching requires issuing AT+S.WIFI=0 followed by AT+S.WIFI=1 and appropriate configuration (e.g., AT+S.SSIDTXT for AP SSID), with a full reset via AT+CFUN=1 to apply changes.
What is the role of the external SPI Flash memory?
The external SPI Flash stores the static HTTP server filesystem (HTML/CSS/JS assets), SSL/TLS certificates, and firmware update images. Commands like AT+S.HTTPDFSWRITE, AT+S.HTTPDFSERASE, and AT+S.FWUPDATE directly manage this memory. The module boots from internal Flash but mounts the external Flash at runtime for web content and crypto material persistence.
SPWF01SA.21 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- Module
- Packaging:
- Tray
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- RF Family/Standard:
- WiFi
- Protocol:
- 802.11b/g/n
- Modulation:
- DSSS, OFDM
- Frequency:
- 2.4GHz
- Data Rate:
- 65Mbps
- Power - Output:
- 18.3dBm
- Sensitivity:
- -96dBm
- Serial Interfaces:
- UART
- Antenna Type:
- Integrated, Chip
- Utilized IC / Part:
- -
- Memory Size:
- 512kB Flash, 64kB RAM
- Voltage - Supply:
- 3.3V
- Current - Receiving:
- 105mA
- Current - Transmitting:
- 210mA ~ 344mA
- Mounting Type:
- Surface Mount
- Operating Temperature:
- -40°C ~ 85°C
SPWF01SA.21 FAQ
1.How can I place an order for SPWF01SA.21 through Aetrix?
Please submit a Request for Quotation (RFQ) for SPWF01SA.21 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for SPWF01SA.21 reliable?
The price and inventory of SPWF01SA.21 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SPWF01SA.21 is usually 5 days.
3.What payment methods are accepted for SPWF01SA.21?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SPWF01SA.21 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SPWF01SA.21?
SPWF01SA.21 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SPWF01SA.21 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for SPWF01SA.21?
For technical support, including SPWF01SA.21 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SPWF01SA.21 requirements.
6.How does Aetrix verify that SPWF01SA.21 is sourced from the original manufacturer or authorized distributors?
All SPWF01SA.21 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that SPWF01SA.21 meets industry standards.
7.What is the process for return or replacement of SPWF01SA.21?
All SPWF01SA.21 units undergo pre-shipment inspection (PSI). If there is an issue with SPWF01SA.21, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The SPWF01SA.21 part is unused and in its original packaging.
Return procedure for SPWF01SA.21:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SPWF01SA.21 Tags
-
ESP32-C3FH4
Espressif Systems
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ESP32-S2FH4
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ESP32-S2FN4R2
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ESP32-C3-MINI-1-N4
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ESP32-C3-WROOM-02-N4
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ESP32-C3-MINI-1U-N4
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ESP32-C3-MINI-1U-H4
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ESP32-C3-WROOM-02U-N4
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ESP32-H2-MINI-1-N4
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ESP32-H2-MINI-1-H4
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