Project Logs

Collapse

• Nothing near finished (do not rebuild yet)

  Steven Roch • 05/18/2016 at 10:07 • 0 comments

  -- UPDATE FOUR--

  So guys,

  today my wires finally arrived but in the meantime I read about the Pi's 3.3V rail and their maximum current draw.

  So I came across this problem that the maximum current the Pi can handle on its 3.3V rail is 51mA (correct me if I'm wrong), which is reached after 3 LEDs lighting up. Take e.g. 19:49 and you will have 15 LEDs burning each drawing 15mAs.

  Since this is my only Pi and I can't afford another one I will rebuild the circuit a little bit but I am not yet sure whether I want to use transistors or go over the 5V rail which can handle 750mA to my knowledge.

  Anyway, Yann Guidon / YGDES who is a follower of this project answered my questions on how to optimize the circuit and we will team up in a second project which will have an optimized version both of the circuit and the code to be more compact.

  I will now upload the source code how it came to my mind when I first thought of the project. Be careful not to re-build my circuit yet because it could potentially damage your Pi!

  When I was testing if everything works my Pi2B did not have any problems or instability problems but I never had more than 7-9 LEDs glowing at the same time and to be honest I do not want to risk executing the code at 19:49!

  I hope you had fun following the project (this is not the end) and I will soon post a link to our (Yann and I) new project. Stay tuned and feel free to follow me for more easy but practical stuff done with the Raspberry Pi.

• Resistance is futile!

  Steven Roch • 05/15/2016 at 19:04 • 0 comments

  -- UPDATE THREE--

  Guys, I couldn't help it. I had to continue working and now the clock is near to its final state.

  I'm lacking 5 m-f-jumper wires but I already ordered some and they are expected to ship on Thursday.

  While waiting I completely assembled the rest of the clock's circuitry and added the lines to get row 3 to work.

  Here's an image of the clock:

  When everything is finished on Thursday I'll post the complete source code as well. I am always open for suggestions on code-improvement and other stuff.

  See you then!

• Getting messy

  Steven Roch • 05/14/2016 at 14:21 • 1 comment

  --UPDATE TWO--

  Now I've come up with a way to reduce the amount of code drastically.

  I will use 10 functions to turn the LEDs on and off depending on the current time. This is 'eight' for example:

  def displayEight(led_1, led_2, led_3, led_4, led_5):
      GPIO.output(led_1, True)
      GPIO.output(led_2, True)
      GPIO.output(led_3, True)
      GPIO.output(led_4, True)
      GPIO.output(led_5, False)

  In addition I installed another row of LEDs today but now I don't have any more LEDs and need to order some which is why I won't be posting any updates for a few days.

  Here's how my breadboard is looking right now (don't mind the knife, I needed to open a pack of resistors):

• Display the minutes, please!

  Steven Roch • 05/13/2016 at 22:09 • 1 comment

  --FIRST UPDATE--

  So after a bit of experimentation I finally came up with an unoptimized code to display the factors of 10 of the minutes.

  Like I said, this is just for me to be sure everything will work like I imagined.

  I took a picture of the testing-setup while it was displaying 23:3xh.

  Today I will continue to get the second part of the minutes section to work.

  Her you have my unoptimized code. Let's see what I can do to make it a bit shorter in the final product:

  #!/usr/bin/python
  # -*- coding: utf-8 -*-
  
  
  # modules
  import RPi.GPIO as GPIO
  from time import strftime, sleep
  
  
  # setup GPIO
  GPIO.setmode(GPIO.BCM)
  GPIO.setup(5, GPIO.OUT)
  GPIO.setup(6, GPIO.OUT)
  GPIO.setup(13, GPIO.OUT)
  GPIO.setup(19, GPIO.OUT)
  GPIO.setup(26, GPIO.OUT)
  
  
  # functions
  def displayTime():
    minutes = strftime("%M")  
    row_3 = int(minutes)/10    
    row_4 = int(minutes)%10    
    if row_3 == 5:
      GPIO.output(5, True)
      GPIO.output(6, False)
      GPIO.output(13, False)
      GPIO.output(19, False)
      GPIO.output(26, False)
    elif row_3 == 4:
      GPIO.output(5, False)
      GPIO.output(6, True)
      GPIO.output(13, True)
      GPIO.output(19, True)
      GPIO.output(26, True)
    elif row_3 == 3:
      GPIO.output(5, False)
      GPIO.output(6, True)
      GPIO.output(13, True)
      GPIO.output(19, True)
      GPIO.output(26, False)
    elif row_3 == 2:
      GPIO.output(5, False)
      GPIO.output(6, True)
      GPIO.output(13, True)
      GPIO.output(19, False)
      GPIO.output(26, False)
    elif row_3 == 1:
      GPIO.output(5, False)
      GPIO.output(6, True)
      GPIO.output(13, False)
      GPIO.output(19, False)
      GPIO.output(26, False)
    else:
      GPIO.output(5, False)
      GPIO.output(6, False)
      GPIO.output(13, False)
      GPIO.output(19, False)
      GPIO.output(26, False)
  
  
  # main program
  def main():
    try:
      while True:
        sleep(0.1)
        displayTime()
    except KeyboardInterrupt:
      GPIO.cleanup()
  
  if __name__ == "__main__":
    main()

  I hope you have fun following the project! See you soon.

• Project Start

  Steven Roch • 05/10/2016 at 21:25 • 0 comments

  Tue, May 10th 2016, 23:25 CEST

  Project started.

View all 5 project logs