2014-06-15 15:56:37 +02:00
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Lego Mindstorms EV3
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Intro
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=====
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This is the buildroot basic board support for the Lego Mindstorms EV3
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2016-11-02 04:15:56 +01:00
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programmable brick.
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2014-06-15 15:56:37 +02:00
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The Lego Mindstorms EV3 brick comprises a Texas Instruments AM1808 SoC, with
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an ARM 926EJ-S main processor running at 300 MHz.
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See:
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- https://en.wikipedia.org/wiki/Lego_Mindstorms_EV3
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- http://www.lego.com/en-us/mindstorms/products/ev3/31313-mindstorms-ev3/
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- http://www.ti.com/product/am1808
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How it works
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============
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Boot process :
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--------------
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2016-11-02 04:15:54 +01:00
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The EV3 boots from an EEPROM. This loads whatever is on the built-in 16MB flash
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(usually U-Boot) and runs it. The U-Boot from the official LEGO firmware and
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mainline U-Boot will attempt to boot a Linux kernel from the external µSD card.
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It will try to load a uImage (and optional boot.scr) from the first µSD card
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partition, which must be formatted with a FAT filesystem. If no µSD is found or
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it does not contain a uImage file, then the EV3 will boot the uImage from the
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built-in 16MB flash.
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2014-06-15 15:56:37 +02:00
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How to build it
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===============
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Configure Buildroot
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-------------------
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The lego_ev3_defconfig configuration provides basic support to boot on the Lego
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Mindstorms EV3 programmable brick:
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$ make lego_ev3_defconfig
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Build everything
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----------------
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Note: you will need to have access to the network, since Buildroot will
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download the packages' sources.
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$ make
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Result of the build
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-------------------
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After building, you should obtain this tree:
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output/images/
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2016-11-02 04:15:54 +01:00
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├── boot.vfat
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├── flash.bin
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2014-06-15 15:56:37 +02:00
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├── rootfs.ext2
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├── rootfs.ext3 -> rootfs.ext2
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2016-11-02 04:15:54 +01:00
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├── rootfs.squashfs
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├── sdcard.img
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├── u-boot.bin
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2017-05-16 01:21:23 +02:00
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├── uImage -> uImage.da850-lego-ev3
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└── uImage.da850-lego-ev3
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2014-06-15 15:56:37 +02:00
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2016-11-02 04:15:54 +01:00
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Installation
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============
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2014-06-15 15:56:37 +02:00
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2016-11-02 04:15:54 +01:00
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You can use either flash.bin or the sdcard.img. To load flash.bin, use the
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official Lego Mindstorms EV3 programming software firmware update tool to load
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the image. To use sdcard.img, use a disk writing tool such as Etcher or dd to
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write the image to the µSD card.
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2014-06-15 15:56:37 +02:00
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2018-12-27 20:53:05 +01:00
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NOTE: The sdcard.img created by lego_ev3_defconfig won't boot if the official
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LEGO firmware is installed on the EV3 (it has an old version of U-Boot that
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doesn't know about device tree). You must either set the kernel configuration
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option to append the device tree to the kernel or you can create a boot.scr
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that chainloads a newer U-Boot or you can install a newer U-Boot in the flash
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memory (just flashing u-boot.bin is enough).
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2014-06-15 15:56:37 +02:00
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Finish
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======
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To have a serial console, you will need a proper USB to Lego serial port
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adapter plugged into the EV3 sensors port 1.
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See:
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- http://botbench.com/blog/2013/08/15/ev3-creating-console-cable/
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- http://botbench.com/blog/2013/08/05/mindsensors-ev3-usb-console-adapter/
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The serial port config to use is 115200/8-N-1.
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2018-12-27 20:53:05 +01:00
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Bluetooth
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=========
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To enable Bluetooth:
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# modprobe hci_uart
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# /usr/libexec/bluetooth/bluetoothd &
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# bluetoothctl
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[bluetooth]# power on
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