BeagleBone Black RFID Adaptor Cape

Description
The RFID adaptor cape is an interface between the Beaglebone Black (BBB) and Texas Instrument's TRF7970ATB, (Multi-Protocol Fully Integrated 13.56-MHz RFID and NFC Transceiver) It allows users to have fully functional RFID and NFC capabilities on the BBB. The adaptor board also features four additional LEDs and a push button.

The communication between the BBB and the TB is via SPI. Since SPI pins are not automatically enabled on BBB, a device tree overlay is used to configure the pins properly for SPI use.

SPI Device Tree Overlay Setup
NOTE: You CAN NOT use SPI1 on the BeagleBone Black WITHOUT disabling the HDMI interface Create a file called BB-SPI1-01-00A0.dts and copy-paste the following code into the file /dts-v1/; /plugin/;

/ {   compatible = "ti,beaglebone", "ti,beaglebone-black";

/* identification */ part-number = "spi1mux";

fragment@0 { target = <&am33xx_pinmux>; __overlay__ { spi1_pins_s0: spi1_pins_s0 { pinctrl-single,pins = < 0x190 0x33     /* mcasp0_aclkx.spi1_sclk, INPUT_PULLUP | MODE3 */ 0x194 0x23     /* mcasp0_fsx.spi1_d0, INPUT_PULLDOWN | MODE3 */ 0x198 0x03     /* mcasp0_axr0.spi1_d1, OUTPUT_PULLDOWN | MODE3 */ 0x19c 0x13     /* mcasp0_ahclkr.spi1_cs0, OUTPUT_PULLUP | MODE3 */ >;           };        };    };

fragment@1 { target = <&spi1>; __overlay__ {

#address-cells = <1>; #size-cells = <0>; status = "okay"; pinctrl-names = "default"; pinctrl-0 = <&spi1_pins_s0>; cs-gpios = <&gpio4 17 0>;

spidev@0 { spi-max-frequency = ; reg = <0>;   /* Use 0 if you want CS0 */ compatible = "linux,spidev"; spi-cpha; };       };    }; };

Compile the dtc: dtc -O dtb -o BB-SPI1-01-00A0.dtbo -b 0 -@ BB-SPI1-01-00A0.dts Then, copy the file into /lib/firmware/: cp BB-SPI1-01-00A0.dtbo /lib/firmware/ Then enable the device tree overlay: echo BB-SPI1-01 > /sys/devices/bone_capemgr.*/slots

Plug in your BBB to a host computer using the mini usb data cable.

Go to My Computer>BeagleBone Getting Started> and open uEnv.txt Copy and paste this command into the .txt file. Make sure to save your changes. (Ctrl+s)

optargs=quiet drm.debug=7 capemgr.disable_partno=BB-BONELT-HDMI,BB-BONELT-HDMIN capemgr.enable_partno=BB-SPI1-01 after you save the changes, reboot your beaglebone black Make sure it is enabled You should now have two spidev-files in the folder /dev/ ls -al /dev/spidev1.*