Hello! I have made an LED cube that is meant to be put to use with and Arduino Uno. The LED cube that I have constructed requires exactly 20 pins to operate. To do this, I need to use digital pins 0-13, and Analog A0-A5. Thing is, I'm worried about using pins 0 and 1 (digital). Is it okay if I have a program that sets them as output. Then, before it starts uploading, remove the wires from pins 0 and 1. Then, once it finishes put the wires back in? Thanks in advance.
Mr_Roboman4321:
Hello! I have made an LED cube that is meant to be put to use with and Arduino Uno. The LED cube that I have constructed requires exactly 20 pins to operate. To do this, I need to use digital pins 0-13, and Analog A0-A5. Thing is, I'm worried about using pins 0 and 1 (digital). Is it okay if I have a program that sets them as output. Then, before it starts uploading, remove the wires from pins 0 and 1. Then, once it finishes put the wires back in? Thanks in advance.
Yes, that will work. Pins 0 and 1 wire to the rec and send lines of the USB serial converter chip but if your not using any serial functions in your sketch then you can repurpose those two pins. And you may or may not have to disconnect your wiring to pins 0 and 1 before you can upload a sketch from the IDE depending on if you are using the pins as inputs or outputs.
Keep in mind even if not using serial commands in your sketch, pin 0 will act like it's wired to a 1K ohm pull-up resistor due to the wiring to the serial USB chip.
Lefty
pin 0 will act like it's wired to a 1K ohm pull-up resistor due to the wiring to the serial USB chip.
This will inevitably effect the brightness of the LEDs connected to that pin. Any way to get around it?
Mr_Roboman4321:
pin 0 will act like it's wired to a 1K ohm pull-up resistor due to the wiring to the serial USB chip.
This will inevitably effect the brightness of the LEDs connected to that pin. Any way to get around it?
No. The USB serial converter chip will be outputting a steady HIGH when there is no serial data active as that is the state of TTL serial logic during a MARK/STOP/IDLE state and that is wired via a series 1K ohm resistor to arduino digital pin 0.
Lefty
Mr_Roboman4321:
pin 0 will act like it's wired to a 1K ohm pull-up resistor due to the wiring to the serial USB chip.
This will inevitably effect the brightness of the LEDs connected to that pin. Any way to get around it?
No it won't, once you have set the pin as an output the 1K resistor will have no significant effect.
dc42:
Mr_Roboman4321:
pin 0 will act like it's wired to a 1K ohm pull-up resistor due to the wiring to the serial USB chip.
This will inevitably effect the brightness of the LEDs connected to that pin. Any way to get around it?
No it won't, once you have set the pin as an output the 1K resistor will have no significant effect.
Sure seems like the 5mA the pin sinks when outputting a LOW will have some measurable effect. It will at least subtract 5mA from the amount the pin can sink for the user's circuitry, right?
afremont:
dc42:
Mr_Roboman4321:
pin 0 will act like it's wired to a 1K ohm pull-up resistor due to the wiring to the serial USB chip.
This will inevitably effect the brightness of the LEDs connected to that pin. Any way to get around it?
No it won't, once you have set the pin as an output the 1K resistor will have no significant effect.
Sure seems like the 5mA the pin sinks when outputting a LOW will have some measurable effect. It will at least subtract 5mA from the amount the pin can sink for the user's circuitry, right?
Correct.