Multiplexing PPDB 17 segment display With 2x PCA9555 - LED Flicker

Jorge P

Hi all, I finally got around to connecting 2x PCA9555's to the Propeller Professional Development Boards 6x - 17 segment displays. It does a test of all digits and segments, then displays the word DONE.

But... When displaying the word DONE, I notice some flicker, How can I eliminate the flicker? I want to fix this before I continue. It is sorta small, but I notice it and it bugs me. I sense that as I write longer code the flicker will increase.

Added my code and the PCA9555 driver in the attached zip. I appreciate any help with this as the connections to the display can be daunting.O_o Wiring diagrams are in the comments.

Finally making some progress here

Here is a video of the Program running, when the camera Zooms you can see the flicker, it is more noticeable than what the video shows.

davejames

Jorge - I posted a response in your blog.

DJ

Jorge P

Thanks for the response, I replied in the Blog as well. I am thinking I am not doing something right in the code someplace, I am not an expert on spin, I just read and reread the datasheets and crossed my fingers. It works but I think as the program gets longer, and more complex, the flicker will increase even more.

kwinn

Jorge P wrote: »

Thanks for the response, I replied in the Blog as well. I am thinking I am not doing something right in the code someplace, I am not an expert on spin, I just read and reread the datasheets and crossed my fingers. It works but I think as the program gets longer, and more complex, the flicker will increase even more.

If you have an extra cog available try using it just for driving the display.

Jorge P

Thanks for the tip kwinn, I will try an attempt at spinning my first cog in a few hours. As far as I can see, only one cog is used throughout my code and the PCA9555 driver. I was planning on separating a few things like the I2C communications part from the PCA9555 driver, but I will most likely brake something, fingers crossed knocking on wood.