Wifi Module - Wifi communication module, based on Texas Instruments CC3000 IEEE 802.11b/g - Schematics based on the design reference from Texas Instruments CC3000 PCB considerations: - 2 layers board - 25 mils trace width for VBAT_IN and VIO_HOST; - 16 mils for antenna traces; - 6 mils for all other traces; - 6 mils minimum clearance for copper to copper; - Via with 13 mils hole and 7 mils annular ring; - Test point vias 12 mils hole and 6 mils annular ring; - All vias below components have solder mask to prevent short circuit when reflowing/soldering SMD components; - CC2564 footprint based on Texas Instruments reference design and documentation; Antenna considerations: - The recommended antenna by Texas Instruments for the CC3000 is the ACX AT8010, but the equivalent one is the Johanson 2500AT44M0400 antenna (the last one is available in stores). - It is important to maintan the size of the antenna keepout and the feed point positioning/distance as specified in the antenna datasheet; however, for this particular design the keepout area was based on Texas Instruments CC3000 Evaluation Module design (the keepout area is smaller). - Be aware that the performance of the chip antenna (shown in the datasheet) was measured using a specific ground plane size and shape; in other words, the ground plane total area and shape modifies the antenna performance. Therefore, after integrating this PCB to your own design, consider building a prototype to test the antenna performance. - Alternatively, you can change the chip antenna to whatever you want/need (for instance - PCB pattern antenna or dipole antenna), just remember to match the impedances from the chip pins to the antenna, that usually is 50ohms. Please, take a look at the CC3000 datasheet for design reference to use a dipole antenna. MODULE Pins description: - 1 - VBAT_IN - Input - Power supply (range 2.7V to 4.8V). - 2 - VIO_HOST - Input - VIO host supply voltage (range 1.8V to 3.6V). - 3 - GND - Ground (0V). - 4 - SPI_CS - Input - Host Interface SPI chip-select(CS). - 5 - SPI_DOUT - Output - Host Interface SPI data out. - 6 - SPI_DIN - Input - Host Interface SPI data in. - 7 - SPI_IRQ - Output - Host Interface SPI interrupt. - 8 - SPI_CLK - Input - Host Interface SPI clock. - 9 - VBAT_SW_EN - Input - Module enable. Connect to host GPIO. - 10 - WL_RS232_TX (TP4) - Output - RS232 test-mode signal (1.8V logic). Connect to test point. Serial connection for CC3000 radio tool. - 11 - WL_RS232_RX (TP5) - Input - RS232 test-mode signal (1.8V logic). Connect to test point. Serial connection for CC3000 radio tool. Please refer to the datasheet for precise voltage logic level at each port. Technical documents/information about the CC3000: http://www.ti.com/lit/ds/symlink/cc3000.pdf