So i will need 1 DC power supply that outputs 5V@2A and i will connect it to my shield as mentioned to the tutorial and it will power up the 2 boards.Now my question is , how many other power supplies and what voltage should i need to power all other stuff ?For example the (1) DC fan needs 5V@200mA and the lcd needs 5V@1A.Can you advice me ? thanks !
Any of the boards or sensors need a low noise supply - for instance audio amp? It's usually a good idea to avoid sharing a supply between digital logic and sensitive analog circuitry to reduce the noise from the logic - for instance a microphone amp should not share supply witha microcontroller - noise levels of microvolts matter for microphone signals.
And sharing anything with an SD card is just asking for *buzzzzzz* trouble.
If all the devices run at 5V, then you could use one single 5V supply which can provide *AT LEAST* the total amount of current draw for all the devices.So, for 3 devices which are, for example, 5V, and 1A, 800mA and 120mA respectively, a power supply of 5V and at least 1920mA would be needed, so a 2A would just about do for that. I like to add a bit of extra for leeway, so a 2.5A 5V supply would work for that example.
the lcd needs 5V@1A.
Quote from: majenko on Nov 07, 2012, 01:14 pmAnd sharing anything with an SD card is just asking for *buzzzzzz* trouble.i didn't understand this about the sd ! can you explain it ?
So you are telling me that if my sensors are analog , i will get wrong voltage by the buzz from other stuff right ? and that i have to avoid it like an sd card will effect an analog gas sensor
Quote from: invader7 on Nov 07, 2012, 01:50 pmSo you are telling me that if my sensors are analog , i will get wrong voltage by the buzz from other stuff right ? and that i have to avoid it like an sd card will effect an analog gas sensorIt might. It all depends on the sensors and how sensitive they are to power supply noise.