As a total beginner in electronics, I would be interrested in having your enlightened opinion, with one main objective in my mind : not to fry my arduino the first time I flow current through it ! (I’d rather wait the second or third time XD). I know it is generally preferred to have practiced a bit before posting, but I am not yet equipped (it is a matter of days), so it is all done mentally for now !
You will find below my preliminary schematics for a personal project concerning photography, which consists in :
- taking an indefinite number of photos at a regular frequency OR
- taking one photo when a remote trigger is pressed
The components are :
a) Arduino Uno Rev3
b) Servo : Tower Pro SG90
c) Radio receiver : based on chip SC2272-M4 (some background here for instance : http://dzrmo.wordpress.com/2012/07/08/remote-control-pt2272-for-android/)
d) 24-step rotary encoder, which is also a button
e) Standard backlit LCD screen (some doc here : https://boutique.semageek.com/fr/index.php?controller=attachment&id_attachment=23)
f) Pololu 5V Step-Up/Step-Down Voltage Regulator S7V7F5, which I will feed with 2 or 3 NiMH AA batteries
My only question is :
Is there any major problem with my design = will it run safely ?
Well, while I am at it I do not mind some counselling on the following :
- If it is OK, I will then play around and test the benefit of adding some extra “protection” : decoupling the source with capacitors, adding a flyback diode across the servo, handling the encoder rebounds with capacitors is mainly what I thought of.
- After I could measure the current draw (I anticipate between about 100 mA and 250 mA), I would like to reduce the energy needs of my circuit (by hardware I mean, software will be “optimized” from the start). I thought of driving the radio receiver, the LCD backlight and the servo with MOSFETs. It is a good idea, and are there some things to know before I make some tests ?
Thank you in advance for your advice