The document discusses the Intel Edison, a compact system-on-module with specifications compared to the Raspberry Pi 3. It covers hardware and software experiences, connectivity options, and potential issues with GPIO usage impacting performance. Additionally, it details Linux distributions and file system safety protocols for embedded systems, emphasizing the importance of ensuring system integrity during operations.

1. Intel Edison: Beyond the breadboard
1
By: Yeo Kheng Meng (yeokm1@gmail.com)Hackware v1.9 (29 June 2016)

2. Why beyond the breadboard?
2
One of Algoaccess’s hardware product

3. 3
Algo Access’s hardware setup
OD, OS, CYL…
OD, OS, CYL…
Direct or USB-Ethernet adapter
RS232 DB-9 Serial port

4. Agenda
1. Intel Edison Basics
2. Hardware experience
3. Software experience
4

5. So what is the Intel Edison?
5
35.5mm x 25 mm x 3.9mm System-on-module (SOM)
• Using Hirose 70-pin DF40 Series Connector (0.4mm pitch)

6. Raspberry Pi 3 vs Intel Edison specifications
6
Specifications Raspberry Pi 3 Intel Edison
CPU 1.2Ghz quad-core BCM2837
Cortex-A53
ARMv8 (64-bit)
500Mhz dual-core Intel Atom x86 (32-bit)
+
Intel Quark MCU
GPU 400Mhz Videocore IV None
RAM 1GB DDR2 1GB DDR3
Storage External microSD cad 4GB eMMC flash onboard
Networking Single band 802.11n Wifi + Dual-mode BT + LAN Dual-band 802.11n Wifi + Dual-mode BT
I/0 Connectivity 3.3V level level GPIO bank + connectors 1.8V logic level GPIO-bank
Price US$35 US$50++
Power consumption (Idle/Peak) 1W/3.6W 0.1W / 1 W
Dimensions 85 x 56 x 17mm 35.5 x 25 x 3.9mm

7. 2 models of Intel Edison
7
No chip antenna image from:
http://www.nix.ru/autocatalog/thin_clients/208148_2254_draft_large.jpg
From Intel Edison Compute Module Hardware Guide (June 2016) Page 13
http://www.intel.com/content/www/us/en/support/boards-and-kits/000005808.html

8. Official Intel carrier boards
8
Mini Breakout board
• USB Serial
• USB-OTG
• GPIO pins (1.8V logic level)
• ~US$25
Arduino Breakout board
• Arduino-style pins
• USB-Serial
• USB-OTG
• Micro-SD slot
• DC Jack 7-15V DC
• 3.3V or 5V logic levels depending on J9 position
• Default is 5V
• ~US$60
https://www.arduino.cc/en/ArduinoCertified/IntelEdison

9. Sparkfun stackable/carrier boards
9
Base Block
64x48 0.66” OLED + buttons “Level-shiftable” GPIO breakout 9-DOF IMU Dual H bridge Battery board

10. Prototyping: Bare breakout board
10
• Hirose 70-pin DF40 Series Receptacle Connector (0.4mm pitch)
• Tough to solder by hand without magnifying glass/microscope
• Stencil highly recommended to avoid solder bridges
• https://github.com/algoaccess/intel-edison-pin-breakout

11. Hirose 70-pin DF40 interface
11
Pin Function Description
1, 5, 9, 11, 13,
15
GND Ground
2, 4, 6 VSYS in Power Input (3.3V to 4.5V)
14 DCIN Connect to VSYS if powered from
external power
8, 10, 12 3.3V/1.8V out Reference voltage (100mA)
46, 61, 63, 65 UART1
(with flow
control)
UART with flow control
/dev/ttyMFD1
22, 27 UART2
(no flow control)
Linux debug serial port
/dev/ttyMFD2
3, 16, 18, 20 USB
(USB_VBUS does
not supply
power)
USB interface
41, 43
45, 47
I2C1
I2C6
2x I2C interfaces
Only master supported
51, 53,
55, 57, 59
SPI Master/Slave supported
Chip select: 51, 53
Picture from: https://learn.sparkfun.com/tutorials/general-guide-to-sparkfun-blocks-for-intel-edison
All pins except power and USB operate at 1.8V levels

12. 1.8V logic levels
• All pins except power and USB operate at 1.8V levels
• But most chips are using 3.3/5.0 V
• For eg, MAX3232 RS232-TTL transceiver (3.3V)
• Use a level shifter like TXS0108EPWR
• Reference 1.8V from Module Pin 12
• For LEDs, you can just use a transistor
12

13. Bug: Using GPIO48 destabilises Wifi
13
http://iotdk.intel.com/docs/master/mraa/edison.html
Arduino Pin 7 can sometimes
negatively impact the WiFi capability,
if using WiFi avoid using this pin
Pin Naming Aliases:
GP48
Compute Module Pin 32
Arduino Pin 7

14. Avoid GPIO48
14J19, Pin 6

15. USB On-The-Go
15Adapted from Intel Edison Compute Module Hardware Guide (June 2016) Page 36
http://www.intel.com/content/www/us/en/support/boards-and-kits/000005808.html
• Host mode
• Connect USB peripherals like flash drives
• Client mode
• Loading firmware (DFU mode)
• USB OTG supports both Host and Client
• Can use a Double pole, double throw (DPDT) switches
USB Role USB_ID
(Pin 3)
FAULT
(Pin 19)
USB_VBUS
(Pin 20)
Host GND Floating Floating
Client Floating GND Host 5V
GND
Fault
USB_ID
USB-A Power Line
USB_VBUS
Source 5V
Client
Host

16. Intel Edison Linux Distributions
1. 1.6 (Default)
• Based on “Poky” Linux distribution
• Compile Poky Linux sources/packages using provided toolchain and recipes
• Limited “opkg” package manager and few default packages
• (eg, no nano, only vi)
• Can add third party “meta-openembedded” recipes during compile time
2.
• Produced by Emutex Labs
• Based on Debian 7 Wheezy (2013)
• More packages compared to Yocto using (apt-get)
• Packages outdated compared to Debian 8 Jessie (2015)
3. Compile your own: Yocto or Debian Jessie
• All use old kernel version 3.10.17 (Oct 2013)
16

17. Poor default support for USB-Ethernet and USB-Serial adapters
• Only supports adapters based on these chipsets
• Ethernet: ASIX AX88xxx USB 2.0 to Gigabit adapter
• Serial: Prolific PL2303 USB-Serial adapter
• More support requires kernel recompilation 17

18. Small rootfs partition size
18
• 1.4GB, 541MB available on initial boot, may be too small for some uses
• Modifying rootfs partition size requires recompilation

19. My compilation script
• Compiles in all available USB-Ethernet/Serial drivers, custom rootfs size
• Downloads sources, modifies compile options then compile
• https://github.com/algoaccess/edison_mod_kernel_image_gen
19

20. Lengthy compilation time
• 4-6 hours typical
• Use the cloud -> Google Compute Engine or AWS (About half hour on 32 threads)
• export SETUP_ARGS="--parallel_make=32 --bb_number_thread=32"
• IMPORTANT: Remember to SHUT DOWN your instance once finished, if not hefty charges will be incurred!!! 20

21. File System safety for embedded systems
• Improper shutdown of systems can corrupt file systems
• Cause: System off while data is being written
1. Read-only file system
• No writes to file-system allowed, no chance of system corruption
2. Enable full-journaling
• File-system journals store a list of changes to be made
• Ext4 default is to journal meta-data only, not the data itself
• We should also journal the data for additional protection
21

22. Read-only file system (preferred)
• ----------------/etc/fstab------------------------
rootfs / auto ro 1 1
/dev/disk/by-partlabel/boot /boot auto ro 1 1
/dev/disk/by-partlabel/home /home auto ro 0 2
tmpfs /var/tmp tmpfs nodev,nosuid 0 0
tmpfs /var/log tmpfs nodev,nosuid 0 0
• ------------------------------------------------------
• tmpfs: RAM drive
• nodev,nosuid: Security precautions for world-writeable file-systems
22https://gist.github.com/yeokm1/00bf00fbcda99cc33c2b

23. Mount file system to journal everything
• Set journal option to / partition
• tune2fs -o journal_data /dev/mmcblk0p8
• Set journal option to /home partition
• tune2fs -o journal_data /dev/mmcblk0p10
• ----------------/etc/fstab------------------------
• rootfs / ext4 data=journal,sync,noatime 1 1
• /dev/disk/by-partlabel/boot /boot auto ro 1 1
• /dev/disk/by-partlabel/home /home ext4 data=journal,sync,noatime 0 2
• ------------------------------------------------------
• data=journal: Journal everything. Data will be written twice, first in to journal, second into disk
• sync: Commit changes to disk immediately, do not cache. Performance loss
• noatime: Do not store last access time to increase disk performance to avoid updating access time in every sync
23

24. QnA
24