BeagleBone Black RFID Adaptor Cape

From eLinux.org
Revision as of 21:20, 25 July 2013 by Szhao (talk | contribs) (Sample Code)
Jump to: navigation, search
BeagleBone Pin Usage

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.

Schematic



RFID Adaptor Cape Schematic RFID Adaptor Cape Layout BeagleBone Pin Usage

Sample Code

The following code is our RFID C application. It will constantly scan for RFID tags within the vicinity of the reader. Once a tag is detected, its UID will be stored in uid.txt file.
RFID Application

SPI Device Tree Overlay Setup

The following information is slightly modified from BeagleBone Black Enable SPIDEV

NOTE: You MUST disable the HDMI interface to use SPI1 to talk to the adaptor cape.
Create a file called BB-SPI1-01-00A0.dts [[ 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

Save the changes, reboot Beaglebone Black.
Make sure it is enabled You should now have two spidev-files in the folder /dev/

ls -al /dev/spidev1.0

If you don't see it, you can type the following to manually enable the device tree overlay.

echo BB-SPI1-01 > /sys/devices/bone_capemgr.*/slots

Eagle Files

References