Hello, so for a project I'm currently doing I'm using multiple arduino uno's to power 7-segment displays. The way I've attempted to go about it at first is to use one main Arduino Uno that sends a signal to 3 other arduino's which each power a 7-segment. When the Arduino's receive said signal they are to change their numbers to a preset sequence, and with each new signal it receives, it will product the next number it is pre-set amount.
The issue I'm having is currently I've been attempting to send a signal from the 'master' arduino and then when the pins turn high on my other arduino's they then do the changing of the segments. When I've done this in practice, the 7-segments tend to change by themselves without any input from the 'master' arduino.
What is the best way to go about this? Do I have the right idea and if so could interference be an issue?
This is my first project the Arduino's so my knowledge is quite shaky to say the least. I've attached 1 of the arduino codes that is programmed to do something when a signal is received. I have also attached the main program since both are quite big I didn't want to spam with code.
My project by the way, is a device that presents users with simple questions and 3 displays that will show a number, with one of the numbers being right. The user then presses a switch that relates to the display and will say whether or not it is incorrect.
Thank you in advance, I'm unsure on how to go about asking this issue so apologies in advance if this topic is viewed wrongly!.
Our knowledge of your project is just as shakey as yours. You have not described or given a drawing of how the arduinos are connected. You failed to include the program you promised.
Have you tried to eliminate all code, except what relates to the communicating signal?
Paul_KD7HB:
Our knowledge of your project is just as shakey as yours. You have not described or given a drawing of how the arduinos are connected. You failed to include the program you promised.
Have you tried to eliminate all code, except what relates to the communicating signal?
Paul
I haven't tried, no. I'll have to give it a go. The program is now included, the files failed to upload immediately so I had to wait before i could go ahead and do it.
To simplify what I'd want to do is take for example having the 'master' Arduino use pins digital pins 9,8,7 to each be connected to pin 10 on each arduino that is being driven. So pin 9 from master to pin 10 on segment etc. So that when I make pins 9,8,7 HIGH the inputs will also see this as HIGH and do what I'd like them to do? Should this work by using pull up/down resistors to eliminate any interference theoretically?
Is the reason that you are using multiple Arduinos simply that you ran out of pins? If it is then you should look at using a single Arduino with a shift register chip(s). As a shift register usually has 8 outputs, you can assign one shift register to each 7 segment display (and use the eighth output to control the decimal point LED if you have one). You can chain the shift registers together, so with the same set of control outputs on the Arduino you can control many shift register chips.
I have a scoreboard with 13 x 7 segment LED numbers which are controlled by a single Arduino Uno with 13 shift register chips chained together. You can also get high current shift registers like the TPIC6B595.