{"id":704,"date":"2022-01-02T03:41:31","date_gmt":"2022-01-02T03:41:31","guid":{"rendered":"https:\/\/www.ebnet.us\/?p=704"},"modified":"2022-05-03T12:20:49","modified_gmt":"2022-05-03T16:20:49","slug":"showing-cpu-usage-and-temperature-with-blinkt-on-your-raspberry-pi","status":"publish","type":"post","link":"https:\/\/www.ebnet.us\/index.php\/2022\/01\/02\/showing-cpu-usage-and-temperature-with-blinkt-on-your-raspberry-pi\/","title":{"rendered":"Blinkt! Watch CPU & Temperature Visually with a Raspberry Pi"},"content":{"rendered":"\n
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Blinkt!<\/h2>\n\n\n\n

While I was using pimoroni<\/a> example scripts to show CPU usage on my Docker Swarm nodes running on my Raspberry Pi 4b I wanted more. I found the is Docker image cisecke\/blinkt-cpu-info<\/a> however I felt no need to run this Python script as a container. The advantage of this is the script will startup immediately on bootup and not rely on Docker.<\/p>\n\n\n\n

First you should have Blinkt! installed. You can go to the official GitHub repository here<\/a> for their installation instructions or run these commands.<\/p>\n\n\n\n

curl https:\/\/get.pimoroni.com\/blinkt | bash<\/code><\/pre>\n\n\n\n
Or on Raspbian<\/p>\n\n\n\n
sudo apt-get install pimoroni<\/code><\/pre>\n\n\n\n
Now since I wasn’t a fan purple I had to edit cisecke’s script to run without Docker and recognize I’m using a Blinkt!. His script also supports LED Shim. Here’s my edited script.<\/p>\n\n\n\n
led.py<\/p>\n\n\n\n
#!\/usr\/bin\/env python\n\nimport signal\nimport os\nimport time\nimport psutil\nfrom subprocess import PIPE, Popen\nimport sys\nimport math\n\n\n#device = os.environ['Device'].lower()\ndevice = \"blinkt\".entry-title {\ndisplay: none;\n}\nif device not in ['blinkt', 'shim']:\n    raise ValueError('Device not recognized.')\nif device == \"shim\":\n    import ledshim as output_device\nelse:\n    import blinkt as output_device\n\n#mode = os.environ['Mode'].lower()\nmode = \"mixed\"\nif mode not in ['mixed', 'temp', 'load']:\n    raise ValueError('Mode not recognized.')\n#brightness_parameter = os.environ['Brightness'].strip()\nbrightness_parameter = .5\nif brightness_parameter and not brightness_parameter == \"\":\n    brightness = min(float(brightness_parameter), 1)\nelse:\n    if device == 'shim':\n        brightness = 1\n    else:\n        brightness = 1\n#interval = max(float(os.environ['Interval']), 0)\ninterval = 0.05\n#smooth = os.environ['Smooth'].lower() == \"true\"\nsmooth = \"false\"\n#marker_parameter = os.environ['Marker'].lower().strip()\nmarker_parameter = \"false\"\nif marker_parameter in ['true', 'false']:\n    marker = marker_parameter == \"true\"\nelse:\n    marker = device == \"shim\"\n#segmented_parameter = os.environ['Segmented'].lower().strip()\nsegmented_parameter = 'false'\nif segmented_parameter in ['true', 'false']:\n    segmented = segmented_parameter == \"true\"\nelse:\n    segmented = device == \"shim\"\n#direction = os.environ['Direction']\ndirection = \"RTL\"\n\noutput_device.set_brightness(brightness)\nrunning = True\n\n\ndef sigterm(x, y):\n    global running\n    running = False\n\n\n# Register the signal to the handler\nsignal.signal(signal.SIGTERM, sigterm)\n\n\ndef get_cpu_temperature():\n    process = Popen(['vcgencmd', 'measure_temp'], stdout=PIPE)\n    output, _error = process.communicate()\n    output = output.decode()\n\n    pos_start = output.index('=') + 1\n    pos_end = output.index(\"'\")\n\n    temp = float(output[pos_start:pos_end])\n\n    return temp\n\n\ndef show_graph(temp, load):\n    segment_pixels_count = output_device.NUM_PIXELS \/ 4\n    temp = temp \/ 80 * output_device.NUM_PIXELS\n    if isinstance(load, list):\n        load = [x \/ 100 * segment_pixels_count for x in load]\n    else:\n        load = load \/ 100 * output_device.NUM_PIXELS\n    pixels = range(output_device.NUM_PIXELS)\n    current = 0\n    if direction.lower() == \"rtl\":\n        pixels = reversed(pixels)\n    for x in pixels:\n        r, g, b = 0, 0, 0\n        if temp > 0:\n            r = get_value(temp)\n            temp -= 1\n        if isinstance(load, list):\n            segment_index = math.trunc(x \/ segment_pixels_count)\n            if load[segment_index] > 0:\n                b = get_value(load[segment_index])\n                load[segment_index] -= 1\n        else:\n            if load > 0:\n                g = get_value(load)\n                load -= 1\n\n        # show the marker, if it's not the last pixel and if it's the last pixel of the segment.\n        if marker and current + 1 != output_device.NUM_PIXELS and (current +1) % segment_pixels_count == 0:\n            g = 255\n        output_device.set_pixel(x, r, g, b)\n        current += 1\n\n    output_device.show()\n\n\ndef get_value(value):\n    max_value = 255\n    if smooth and value <= 1:\n        return max_value * value\n    else:\n        return max_value\n\n\ndef show_info():\n    temp = 0\n    load = 0\n    if mode in ['mixed', 'temp']:\n        temp = get_cpu_temperature()\n    if mode in ['mixed', 'load']:\n#        if segmented:.entry-title {\ndisplay: none;\n}\n#            load = psutil.cpu_percent(percpu=segmented)\n#        else:\n            load = psutil.cpu_percent()\n    show_graph(temp, load)\n\n\nif __name__ == '__main__':\n    while True:\n        if running:\n            show_info()\n            time.sleep(interval)\n        else:\n            break\n    # shut off pixels and exit\n    output_device.clear()\n    output_device.show()\n\n\n<\/code><\/pre>\n\n\n\n
Then we need to start the script on boot so we will edit crontab<\/p>\n\n\n\n
crontab -e<\/code><\/pre>\n\n\n\n
An add this line<\/p>\n\n\n\n
@reboot python3 path_to_your_script\/led.py &<\/code><\/pre>\n\n\n\n
Now either reboot or run the script manually and you should get this<\/p>\n\n\n\n