• SDIO
  • SPI
  • Serial or UART


An SDIO (SD Input/Output) interface is an extension of SD memory card specification. The intent of SDIO interface is to provide high-speed input/output through the standard SD card slot for devices. A standard SDIO card inserted into a SDIO compatible host presents the developers with a simple Plug and Play interface support.

The standard card dimensions are 24mm x 32mm x 2.1mm. Redpine Signals has created products which can take advantage of the SDIO capable card slot and allow the customer to add Wi-Fi connectivity to the device. A host SD card slot can be SDIO and non-SDIO compatible. No physical damage or disruption of the host would occur if a SDIO capable card is inserted into a non-SDIO compatible card slot. The SDIO capable card would be ignored by the host. SDIO standard is preferred over SPI interface for better throughput needs. We support both 1bit and 4 bit SDIO mode.

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SPI (Serial Peripheral Interface) is a synchronous serial data link prevalent in embedded devices. It is also known as “four wire” serial bus. The interface is capable of full duplex operation and supports higher throughputs than standard I2C interface. This interface is the de-facto interface on FPGA boards. Redpine Signals has created Wi-Fi modules to support this critical interface. Redpine products operate in mode 0 and mode 3 of SPI standard. The SPI driver is made available as a reference code base for developers to create their custom Wi-Fi enabled applications.

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There are many embedded devices without network connectivity. However, these devices typically have a serial interface. The advances in WiFi coupled with machine to machine technologies allow us to enable network connectivity on such devices. A network capable device allows the customer to increase productivity of the system through real time monitoring and control. Redpine Signals Serial-to-WiFi solution is available in the Connect-io-n family of products. For example, the RS9110-N-11-22 has got full network suite including TCP/IP stack, application protocols like FTP, Web server etc, along with 802.11bgn drivers and 802.1x supplicant embedded into its dual-threaded ThreaArch™ processor. Thus, it eases integration and provides a cost effective low power Serial-to-WiFi solution to any device, which has UART or SPI interface.

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