Posted on July 25th, 2016
Do you ever find yourself inside your ceiling or under the floor working on your home automation system, and need to SSH to a remote machine or re-flash an Arduino?
Sure, you could drag your laptop under there with you, but I don’t want to have my expensive laptop lying around in the dirt or insulation.
I may have found the answer.
C.H.I.P. and Pocket C.H.I.P. will be available soon from getchip.com.
I used “arduino-mk” running on the Pocket C.H.I.P to compile and upload an Arduino sketch: github.com/sudar/Arduino-Makefile
The following sequence got everything working for me. You may want to do things a little differently, for example by managing the python-serial extension using Pip or storing your sketches in a different location. That’s totally up to you, just make sure you alter the paths shown below as necessary.
Start by making sure your package list is up to date, and that you have the latest packaged Arduino and Python serial extension installed on your C.H.I.P.:
sudo apt-get update sudo apt-get dist-upgrade sudo apt-get install python-serial arduino arduino-mk
Create a directory inside your home directory to keep all your Arduino sketches organised:
mkdir ~/sketchbook
Now go into your sketchbook and copy an example project out of arduino-mk, so that it includes the example Makefile:
cd ~/sketchbook cp -a /usr/share/doc/arduino-mk/examples/Blink .
Note the space and the dot at the end of that line!
Now go into the Blink project and see what files it contains:
cd Blink ls -l
You’ll see that there’s both the sketch itself and a Make file:
-rw-r--r-- 1 chip chip 509 Jul 12 2014 Blink.ino -rw-r--r-- 1 chip chip 61 Jul 12 2014 Makefile
There’s nothing unusual about the Blink sketch. It’s just standard Arduino code that you could compile with the regular IDE. The magic is invoked through the Make file.
Open the Make file in your favorite text editor, and you’ll see that it looks like this:
BOARD_TAG = uno ARDUINO_LIBS =
include ../../Arduino.mk
The “BOARD_TAG” value specifies that you want to compile it for an Uno or compatible board. You can change this to match other boards found in the Arduino board hardware definition file, which is located at /usr/share/arduino/hardware/arduino/boards.txt. In that file you’ll find other handy board types that I’ll list at the end. For now, we’ll assume that you’re using an Uno and leave that unchanged.
The “ARDUINO_LIBS” value allows you to specify a path to your own custom libraries in case you need them linked during compilation. We’ll ignore that for now, so leave that line unchanged.
The “include” line is a problem. It assumes the project is still located in the shared location where it was installed by the package, but we’ve made a copy in our local sketchbook. To fix that, change the “include” line to read:
include /usr/share/arduino/Arduino.mk
There are many other options you can add to the Make file to override the default settings within Arduino. For example, you can define the path to a specific version of AVRDUDE if you want to bypass the version that’s bundled with the Arduino environment.
But for a minimal example, you don’t need to change anything else.
Now you can compile the sketch, and upload it to your Arduino. To compile the sketch without attempting to upload it, just type:
make
That’s it! Can’t be much simpler. If there are any compilation errors, you’ll see them in the terminal.
To upload (and automatically compile if necessary) make sure your Arduino is plugged into your Pocket C.H.I.P. using a USB cable, and type:
make upload
You’re all done! Your sketch should now have been uploaded to your Arduino.
There are other commands available as well. Check out the Arduino-MK documentation for more information:
github.com/sudar/Arduino-Makefile
These are all the board tags list in the standard /usr/share/arduino/hardware/arduino/boards.txt file:
uno: Arduino Uno atmega328: Arduino Duemilanove w/ ATmega328 diecimila: Arduino Diecimila or Duemilanove w/ ATmega168 nano328: Arduino Nano w/ ATmega328 nano: Arduino Nano w/ ATmega168 mega2560: Arduino Mega 2560 or Mega ADK mega: Arduino Mega (ATmega1280) leonardo: Arduino Leonardo esplora: Arduino Esplora micro: Arduino Micro mini328: Arduino Mini w/ ATmega328 mini: Arduino Mini w/ ATmega168 ethernet: Arduino Ethernet fio: Arduino Fio bt328: Arduino BT w/ ATmega328 bt: Arduino BT w/ ATmega168 LilyPadUSB: LilyPad Arduino USB lilypad328: LilyPad Arduino w/ ATmega328 lilypad: LilyPad Arduino w/ ATmega168 pro5v328: Arduino Pro or Pro Mini (5V, 16 MHz) w/ ATmega328 pro5v: Arduino Pro or Pro Mini (5V, 16 MHz) w/ ATmega168 pro328: Arduino Pro or Pro Mini (3.3V, 8 MHz) w/ ATmega328 pro: Arduino Pro or Pro Mini (3.3V, 8 MHz) w/ ATmega168 atmega168: Arduino NG or older w/ ATmega168 atmega8: Arduino NG or older w/ ATmega8 robotControl: Arduino Robot Control robotMotor: Arduino Robot Motor
You can also use custom board profiles, but that’s beyond the scope of this post! Most common Arduino compatible boards match something on this list. For example, the Freetronics EtherMega operates just like an Arduino Mega with a 2560 processor, so you’d select “mega2560” as the BOARD_TAG in the Make file.
My friend Alec has written a script to simplify the process of installing the packages I used in the video and also to fix a few things he doesn’t like about the default setup. His script installs the necessary packages, blocks root access to the terminal and SSH, locks the root account, changes the default password, changes the hostname, and forces public key authentication via SSH. Definitely worth a look:
gist.github.com/alecthegeek/434325b6ea261ba84499f4966795073e
