Hi I am creating a project that connects 16 switched to a CD74HC4067 to minimize the pins used on my arduino mega with a Ethernet shield attached.
I am taking the 5volt power output from the from the arduino to power the CD74HC4067 and provide the power for the switches.
Each of the inputs tests ok on the CD74HC4067.
However when I have the first 3 switches in the on position the arduino freezes after a few moments and my laptop makes the sound of a device been connected/disconnected. Also I notice the LED's on the Arduino dim a more with each switch in the on position.
I am certain this means it's a power issue and should I use another power source for the switches and can anyone recommend something suitable.
Disconnect it immediately, you're shorting something out, risking serious damage.
jasemilly:
and provide the power for the switches.
Switches don't require power. They do need a pull-up resistor. You only need one for the entire multiplexer, and it's probably best to use the internal one.
The switches should be connected to ground in that case.
There's nothing we can do without you posting a detailed schematic.
Hi,
Please show a diagram with your components in it, not just wires, connectors and resistors.
Where is your power supply , 4067, switches?
LABEL your components and pins.
May I make a suggestion and you get out a pen and paper and draw the schematic showing the switches, as switch symbols not boxes, your 4067 including pin names and how you have them connected together, along with labelled 5V and gnd wires.
Can you show a picture of your project so you we can see your component layout.
jasemilly:
The image with the labels on didn't upload will try again
No that is just the same as the last image in the previous post.
Sorry but I can’t imagine a more useless set of photos. You can not see any components and any resistors.
We wanted a photograph of your wiring, which generally means a single photo showing where things are connected to each other not odd corners of Solderless bread board. And not a switch in sight.
Why do you have a resistor on every mux input? You can only read one input at a time, so you only need one resistor at the output of the mux. If your wires are short, you can even use the internal pull-up resistor.
I notice three look burned out, something you did not mention before, why not?
Yes they are burnt out. I already had the problem and tried an external power supply. I was very unsure if this was the correct thing so I disconnected the Arduino before applying power. It burnt those 3 out.
I purchased off ebay as 10k resistors I will check the colour bands.