Need some advice regards taking a 9v feed from an Arduino to another component
I have a 9v 2A transformer powering the Arduino and the components connected to and controlled by. One of those components is a relay that supplys a 6v pump. The 6v is to be supplied by the same 9v 2A transformer and is stepped down using a LM2596 Step Down Power Supply.
The question
Can I use the 9v pin on the Arduino or should I solder wires to the Arduino 'External Power Supply In' ?
I'm not sure what the 9v pin should be used for and if it can be used what load it can take - not that a 6v pump will take much.
see the schematic for your board.
Several boards have a 'solderpin' which is ment for external power
This pin in fed to the voltage regulator the same way the barrelconnector is..
thanks for the reply knut_ny
looking at the uno v3 schematic (and not the old one i was looking at) the v3 does not have a 9v pin and i cant see a 'solderpin' so looks like i'll have to solder to the External Power Supply In on the back of the board
unless someone says different
IGraham:
thanks for the reply knut_ny
looking at the uno v3 schematic (and not the old one i was looking at) the v3 does not have a 9v pin and i cant see a 'solderpin' so looks like i'll have to solder to the External Power Supply In on the back of the board
unless someone says different
The UNO have a "VIN" pin, which means "Voltage-in" and it's connected to the barrel connector.
I have a 9v 2A transformer powering the Arduino and the components connected to and controlled by. One of those components is a relay that supplys a 6v pump. The 6v is to be supplied by the same 9v 2A transformer and is stepped down using a LM2596 Step Down Power Supply.
If you haven't already bought your Arduino, this is a cool little board. You could get rid of the relay and the regulator just by using the L298 on board. The L298 loses a few volts, so you would be close to 6V anyway, plus you can control it from a PWM pin to reduce the voltage the motor sees.
rmetzner49
looks interesting, but i already have the Arduino and components and is all set up on a breadboard (except for the 6v to the pump) and am in the processes of moving it all to a working environment. As I'm not at all up to speed with this type of thing probably best i stick with the simpler Arduino - for now.
thanks for the thought though
polymorph
I'll probably pick up the 9v from the power in solder points on the back of the board, that way not risk killing the Aduino - as long as the soldering goes as should
I'm most wary of the vin pin as far as i can tell it can supply the needed 9v to the step down but its not strait through (the arduino) and I'd rather not risk
unless i get a definite 'yes you can' and nothings going to burn out
Connect separate wires to your power source. In that way less of the voltage drops and noise will show up on the Arduino.
Good suggestion.
If you really want to be nice to the Arduino, find a nice low-ESR Electrolytic of around 470uF and connect that across and as close to Arduino's VIN pin as practicable. Between that and the power supply's internal cap a lot of motor noise can be dealt with. The Aruino's on-board regulator will also have 4V difference between input and output which helps with noise immunity.