39296b40d4
Teensy doesn't need to worry about overflows since all of its timers are only 16-bit. For PWM, the pulse width needs to be able to vary from 0..period+1 (pulse-width == period+1 corresponds to 100% PWM) I couldn't test the 0xffffffff cases since we can't currently get a period that big in python. With a prescaler of 0, that corresponds to a freq of 0.039 (i.e. cycle every 25.56 seconds), and we can't set that using freq or period. I also tested both stmhal and teensy with floats disabled, which required a few other code changes to compile.
Build Instructions for Teensy 3.1
Currently the Teensy 3.1 port of Micro Python builds under Linux and not under Windows.
The tool chain required for the build can be found at https://launchpad.net/gcc-arm-embedded.
Downlaod the current Linux *.tar.bz2 file. Instructions regarding unpacking the file and moving it to the correct location as well as adding the extracted folders to the enviroment variable can be found at http://eliaselectronics.com/stm32f4-tutorials/setting-up-the-stm32f4-arm-development-toolchain/
In order to download the firmware image to the teensy, you'll need to use the downloader included with TeensyDuino. The following assumes that you have TeensyDuino installed and set the ARDUINO environment variable pointing to the where Arduino with TeensyDuino is installed.
cd teensy
ARDUINO=~/arduino-1.0.5 make
To upload micropython to the Teensy 3.1.
Press the Program button on the Teensy 3.1
sudo ARDUINO=~/arduino-1.0.5/ make deploy
Currently, the Python prompt is through the USB serial interface, i.e.
minicom -D /dev/ttyACM0
TIPS
Install 49-teensy.rules into /etc/udev/rules.d
If you install the 49-teensy.rules file from http://www.pjrc.com/teensy/49-teensy.rules
into your /etc/udev/rules.d folder then you won't need to use sudo:
sudo cp ~/Downloads/49-teensy.rules /etc/udev/rules.d
sudo udevadm control --reload-rules
Unplug and replug the teensy board, and then you can use: ARDUINO=~/arduino-1.0.5/ make deploy
Create a GNUmakefile to hold your ARDUINO setting.
Create a file call GNUmakefile (note the lowercase m) in the teensy folder with the following contents:
$(info Executing GNUmakefile)
ARDUINO=${HOME}/arduino-1.0.5
$(info ARDUINO=${ARDUINO})
include Makefile
GNUmakefile is not checked into the source code control system, so it will retain your settings when updating your source tree. You can also add additional Makefile customizations this way.