wiki:v2:building_libpixyusb_as_a_python_module_on_linux
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wiki:v2:building_libpixyusb_as_a_python_module_on_linux [2018/04/09 21:52] jfrench - Imported by DokuWiki Advanced Plugin |
wiki:v2:building_libpixyusb_as_a_python_module_on_linux [2019/08/08 21:07] pixycam [Python2 vs Python3] |
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| ====== Using the Python API on Linux ====== | ====== Using the Python API on Linux ====== | ||
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| ====== Introduction ====== | ====== Introduction ====== | ||
| - | Pixy now has a Python wrapper for libpixyusb. For now, this is only available for Linux-based controllers (e.g. Raspberry Pi, BeagleBone). The [[wiki:v2:Building_the_libpixyusb_example_on_Linux|libpixyusb]] library provides a software application programming interface (API) for communicating with Pixy over USB. The following procedure will outline the steps to build libpixyusb as a Python module. | + | Pixy2 now has a Python wrapper for libpixyusb2. For now, this is only available for Linux-based controllers (e.g. Raspberry Pi, BeagleBone). The [[wiki:v2:building_the_libpixyusb_example_on_linux|libpixyusb2]] library provides a software application programming interface (API) for communicating with Pixy2 over USB. The following procedure will outline the steps to build libpixyusb2 as a Python module. |
| This procedure assumes the following: | This procedure assumes the following: | ||
| - | * Your system is Linux (with Debian package manager) | + | * Your system has Linux Mint installed |
| - | * Pixy firmware has been updated to 1.0.2 or higher | + | * Your system is connected to the internet |
| - | * Your system is connected to the internet (for getting packages) | + | |
| - | Instructions for updating the Pixy firmware are here: [[wiki:v2:Uploading_New_Firmware|Uploading New Firmware]] | + | Although this procedure uses Linux Mint, it should work with any Linux distribution that uses the Debian package manager (e.g. Ubuntu). |
| + | ====== Procedure ====== | ||
| + | ===== Install dependencies for building Python SWIG module ====== | ||
| + | Start a terminal application. In the terminal window type: | ||
| - | ====== 2. Procedure ====== | + | ''%%# sudo apt-get install swig libusb-1.0-0-dev g++ git build-essential%%'' |
| - | + | ===== Download Pixy2 source code ===== | |
| - | ===== 2.1. Install dependencies for building Python SWIG module ===== | + | |
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| - | Start a terminal application. | + | |
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| - | + | ||
| - | ==== 2.1.1. Install SWIG ==== | + | |
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| - | In a terminal window type: | + | |
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| - | ''%%# sudo apt-get install swig%%'' | + | |
| - | + | ||
| - | + | ||
| - | ==== 2.1.2. Install libusb-1.0-0-dev ==== | + | |
| In the terminal window type: | In the terminal window type: | ||
| - | ''%%sudo apt-get install libusb-1.0-0-dev%%'' | + | ''%%# git clone https://github.com/charmedlabs/pixy2.git %%'' |
| - | + | ===== Build the Pixy2 SWIG module ===== | |
| - | ==== 2.1.3. Install g++ (compiler) ==== | + | |
| In the terminal window type: | In the terminal window type: | ||
| - | ''%%sudo apt-get install g++%%'' | + | ''%%# cd pixy2/scripts%%''\\ |
| + | ''%%# ./build_python_demos.sh%%'' | ||
| + | ===== Try it out! ===== | ||
| - | ==== 2.1.4. Install libboost ==== | + | Change directory to the build folder. In your terminal window type: |
| - | In the terminal window type: | + | ''%%# cd ../build/python_demos%%'' |
| - | ''%%sudo apt-get install libboost-all-dev%%'' | + | ==== Run the get blocks demo ==== |
| + | Make sure your Pixy2 is connected to a USB port on your computer. Then in a terminal window type: | ||
| + | ''%%# python get_blocks_python_demo.py%%'' | ||
| - | ===== 2.2. Build the libpixyusb Python module ===== | + | If all goes well you should see blocks: |
| + | ''%%Pixy2 Python SWIG Example -- Get Blocks%%''\\ | ||
| + | ''%%frame 0:%%''\\ | ||
| + | ''%%[BLOCK: SIG=1 X=157 Y=103 WIDTH=314 HEIGHT=207]%%''\\ | ||
| + | ''%%frame 1:%%''\\ | ||
| + | ''%%[BLOCK: SIG=1 X=157 Y=103 WIDTH=314 HEIGHT=207]%%''\\ | ||
| + | ''%%frame 2:%%''\\ | ||
| + | ''%%[BLOCK: SIG=1 X=157 Y=103 WIDTH=314 HEIGHT=207]%%''\\ | ||
| + | ''%%frame 3:%%''\\ | ||
| + | ''%%[BLOCK: SIG=1 X=157 Y=103 WIDTH=314 HEIGHT=207]%%''\\ | ||
| - | ==== 2.2.1 Download Pixy source code ==== | + | If you don't see any block information, try running as superuser: |
| - | In the terminal window type: | + | ''%%# sudo python get_blocks_python_demo.py%%'' |
| - | ''%%git clone https://github.com/charmedlabs/pixy.git%%'' | + | ==== Run the get lines demo ==== |
| + | Make sure your Pixy2 is connected to a USB port on your computer. Then in a terminal window type: | ||
| + | ''%%# python get_lines_python_demo.py%%'' | ||
| - | ==== 2.2.2. Build the Python module ==== | + | Example output: |
| - | In the terminal window type: | + | ''%%Pixy2 Python SWIG Example -- Get Line Features%%''\\ |
| + | ''%%frame 0:%%''\\ | ||
| + | ''%%[VECTOR: INDEX=1 X0= 50 Y0= 15 X1= 50 Y1= 5]%%''\\ | ||
| + | ''%%[VECTOR: INDEX=2 X0= 56 Y0= 8 X1= 67 Y1= 4]%%''\\ | ||
| + | ''%%frame 1:%%''\\ | ||
| + | ''%%[VECTOR: INDEX=0 X0= 55 Y0= 27 X1= 51 Y1= 2]%%''\\ | ||
| + | ''%%frame 2:%%''\\ | ||
| + | ''%%[VECTOR: INDEX=0 X0= 55 Y0= 27 X1= 51 Y1= 2]%%''\\ | ||
| + | ''%%frame 3:%%''\\ | ||
| + | ''%%[VECTOR: INDEX=1 X0= 57 Y0= 31 X1= 53 Y1= 21]%%'' | ||
| - | ''%%cd pixy/scripts%%''\\ | + | If you don't see any line feature information, try running as superuser: |
| - | ''%%./build_libpixyusb_swig.sh%%'' | + | |
| + | ''%%# sudo python get_lines_python_demo.py%%'' | ||
| - | ===== 2.3. Try it out! ===== | + | ===== Errors ===== |
| - | Make sure your Pixy is connected to a USB port on your computer. Then in the terminal window type: | + | If you are getting an error like: |
| - | ''%%cd ../build/libpixyusb_swig%%''\\ | + | ''ImportError: No module named _pixy'' |
| - | ''%%python get_blocks.py%%'' | + | |
| - | If all goes well, you should see blocks: | + | Python is having trouble finding the Pixy Python library. This may be because you are running in another directory. Just copy over the \_pixy.so and pixy.py files in the ''pixy2/build/python_demos'' directory to your directory and it should work. |
| - | + | ||
| - | ''%%Pixy Python SWIG Example -- Get Blocks%%''\\ | + | |
| - | ''%%[BLOCK_TYPE=0 SIG=1 X=220 Y= 17 WIDTH= 43 HEIGHT= 35]%%''\\ | + | |
| - | ''%%[BLOCK_TYPE=0 SIG=1 X=220 Y= 23 WIDTH= 42 HEIGHT= 47]%%''\\ | + | |
| - | ''%%[BLOCK_TYPE=0 SIG=1 X=220 Y= 23 WIDTH= 42 HEIGHT= 47]%%''\\ | + | |
| - | ''%%[BLOCK_TYPE=0 SIG=1 X=220 Y= 23 WIDTH= 42 HEIGHT= 47]%%''\\ | + | |
| - | ''%%[BLOCK_TYPE=0 SIG=1 X=220 Y= 23 WIDTH= 42 HEIGHT= 46]%%''\\ | + | |
| - | ''%%[BLOCK_TYPE=0 SIG=1 X=220 Y= 23 WIDTH= 45 HEIGHT= 46]%%''\\ | + | |
| - | ''%%[BLOCK_TYPE=0 SIG=1 X=219 Y= 23 WIDTH= 43 HEIGHT= 46]%%'' | + | |
| - | + | ||
| - | If you don't see any block information, try running as superuser: | + | |
| - | ''%%sudo python get_blocks.py%%'' | + | If you still get an error, you may be running into a Python version issue. Please see the next section. |
| + | ===== Python2 vs Python3 ===== | ||
| + | This library will support both Python2 and Python3, but sometimes it will compile fine but provide import errors when you try to run one of the Python demos. | ||
| + | If you want Python3 support, for example, make sure that your default "python" is Python3 before running ''build\_python\_demos.sh''. That is, make sure that Python3 is the version of Python that runs when you type in the "python" command in your shell. You can test this by running "python --version" at the shell prompt. | ||
| + | If it's not version 3 (or higher), change the default version to be Python3. The recommended way to do this may depend on your Linux distribution. | ||
wiki/v2/building_libpixyusb_as_a_python_module_on_linux.txt · Last modified: 2019/08/08 21:12 by pixycam
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