Ok - so I'm not an electrical engineer first off so pardon my ignorance.
I have a Maxbotix MaxSonar EV0 that I'm trying to use - it just (finally) dawned on me that this is a 5V device and all the analog inputs are 3.3V. So - for me to be able to use this do I need something like this from SparkFun?
Thanks,
-G
EDIT: Nevermind - just noticed that that board is for digital only and my outputs are analog - so how do I step it down? Or am I just SOL?
Just checking - stepping from 5v to 3.3v
Started by greg, Aug 25 2010 01:44 AM
5 replies to this topic
#2
Chris Walker
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Posted 26 August 2010 - 07:36 AM
Do you have a link to the specs for the EV0? I see that the new Maxbotix devices can use either 3.3V or 5V. Some older analog sensor may require 5V power and also use that as their analog input...but some will let you adjust the analog "maximum" value to anything within a range...
You might be able to use a voltage divider to get the range down to 0-2.5V, but we might need to see more of the specs...
#3
greg
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Posted 26 August 2010 - 01:35 PM
Do you have a link to the specs for the EV0? I see that the new Maxbotix devices can use either 3.3V or 5V. Some older analog sensor may require 5V power and also use that as their analog input...but some will let you adjust the analog "maximum" value to anything within a range...
You might be able to use a voltage divider to get the range down to 0-2.5V, but we might need to see more of the specs...
Ask and ye shall receive.
Specs right there.
#4
Chris Walker
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Posted 26 August 2010 - 04:03 PM
Ask and ye shall receive.
Specs right there.
That spec sheet appears to be for the "EZ0" and not the "EV0". Are they the same unit?
According to that spec sheet, you can supply 3.3V power to the device...and you should be good to go...
Chris
#5
greg
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Posted 26 August 2010 - 04:14 PM
That spec sheet appears to be for the "EZ0" and not the "EV0". Are they the same unit?
According to that spec sheet, you can supply 3.3V power to the device...and you should be good to go...
Chris
Probably my typo.
Hmm - ok - I'll have to try that. I hadn't actually read the spec until you requested it - the docs that came with it never mention 3.3V, only 5V so that's what I had it hooked up to. I'll drop it down to 3.3V, cross connect it to AREF and see what happens. Before I was only getting a max reading of 1023 no matter what I did.
#6
greg
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Posted 27 August 2010 - 12:58 AM
Probably my typo.
Hmm - ok - I'll have to try that. I hadn't actually read the spec until you requested it - the docs that came with it never mention 3.3V, only 5V so that's what I had it hooked up to. I'll drop it down to 3.3V, cross connect it to AREF and see what happens. Before I was only getting a max reading of 1023 no matter what I did.
Works like a charm. My rangefinder is a-ok. Pretty neat. Robot power, here I come.
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