Please forgive me if this has been explained somewhere, I can't seem to find anything refering to my problem. I have an Arduino Micro that I have hooked to my motorcycle, I'm using a 9V regulator into VIN. I'm trying to figure out if I can power up the Micro from the motorcycle at the same time I've got the Micro hooked to the USB port on my computer so that I can read the serial data to troubleshoot an issue I'm having. I swear I remember reading somewhere that I can't do this, but I don't know where that was and I don't know if I'm wrong. I just don't want to smoke anything, I've already fried 1 Micro due to user error. Thank you in advance.
You can apply external power via the jack and power via the USB at the same time. The Arduino has circuitry to determine which one to actually use.
If you bypass the jack, and supply 5V directly to Vin, then you've bypassed the safeguards, too. But, you wouldn't be putting 9V into Vin.
So, it isn't clear how you are powering the Arduino.
I swear I remember reading somewhere that I can't do this, but I don't know where that was and I don't know if I'm wrong.
I've powered an old arduino from a 7805 chip directly to the arduino when the onboard regulator failed to regulate the voltage to 5v via the external power jack. I've read that the uno onboard voltage regulation setup is different and might be damaged if the 5v bus is directly powered with 5v. You might find this info on the arduino site where the uno is described.
PaulS:
You can apply external power via the jack and power via the USB at the same time. The Arduino has circuitry to determine which one to actually use.If you bypass the jack, and supply 5V directly to Vin, then you've bypassed the safeguards, too. But, you wouldn't be putting 9V into Vin.
So, it isn't clear how you are powering the Arduino.
The Micro's web page states "External (non-USB) power can come either from a DC power supply or battery. Leads from a battery or DC power supply can be connected to the Gnd and Vin pins.
The board can operate on an external supply of 6 to 20 volts. If supplied with less than 7V, however, the 5V pin may supply less than five volts and the board may be unstable. If using more than 12V, the voltage regulator may overheat and damage the board. The recommended range is 7 to 12 volts. "
I used an ON Semi MC78L00A 9V voltage regulator to get 9V out of the 12-14V from the motorcycle. Ground from the regulator is tied to the Micro's ground and the output of the regulator is tied into VIN. So have I misread this?
Any ideas? I'd really like to figure this out otherwise it was a complete waste of money. I keep searching and I can't find anything relevant. I think I can use an MAX232 chip, but I don't really know. This requires more parts and waiting, I'd like to do it over USB if possible.
brims:
Any ideas? I'd really like to figure this out otherwise it was a complete waste of money. I keep searching and I can't find anything relevant. I think I can use an MAX232 chip, but I don't really know. This requires more parts and waiting, I'd like to do it over USB if possible.
Well, why don't you just try it. If it works, great. if it doesn't work, then it might be a waste of your money.
brims:
I'm trying to figure out if I can power up the Micro from the motorcycle at the same time I've got the Micro hooked to the USB port on my computer so that I can read the serial data to troubleshoot an issue I'm having. ...
You may.
zoomkat:
Well, why don't you just try it. If it works, great. if it doesn't work, then it might be a waste of your money.
And risk frying A) the Arduino and B) the USB port on my laptop, ya, that's not a very good idea. Thought the idea behind open hardware was the same as open source, people help each other.
What a worthless forum this is. I came here asking a legit question, I was respectful, and everyone just wants to give me blatently wrong information or be a complete prick. Good luck with that shit.
brims:
What a worthless forum this is. I came here asking a legit question, I was respectful, and everyone just wants to give me blatently wrong information or be a complete prick. Good luck with that shit.
Blatently wrong?
Replies #1 and #6 gave correct answers to your "question".
Is there a dispute?
Yes, blatently wrong.
I was talking about a Micro and am being given information about an Uno.
I said I want to power it with 9v to Vin and was told that can't be done. I'm doing just that and the Arduino site states that can be done, so again wrong information.
I wanted to know if there was a way to power the Arduino from external power and read the Serial data via USB. Hooking the Arduino to a USB port powers it from USB, not the Vin power. Project works when powering from USB but acts oddly when powered from Vin. So seeing my Serial data is the only way to know what is happening.
If I was an electrical engineer, I would have already read the schematic and never even been on the forum.
I have run into this a few times with the OSEPP pro mini where I have external 12 vdc connected to a 6 vdc regulator then to the raw input of the pro mini. I was using the serial as well for loading and serial monitor . I noticed the regulator was getting hot ( I always do the finger scan over the board to see if anything is getting warm ) . I will go look at the schematic to see what I did to correct this as I have made a few other projects as well since where I corrected this and was able to monitor the circuit while it was live with external wall wort.
BobD
I checked my circuit and it was just a diode in series from the output of the regulator into the raw input of the pro mini . This isolated the upstream circuit from the USB fed 5 vdc to to pro mini.
I would think ( I am not an engineer ) that if you did the same in line diode from your regulator out to the Vin / Raw in to the board you should be protecting the USB for you computer .
I would appreciate any thoughts on this from more experienced members , I do appreciate their insight and advice.
BobD
I would think a low voltage drop diode would provide adequate USB protection.