Hi Guys
Getting started on my first project. I’m helping a friend with a wireless sensor project. it will be one arduino on the bike and one remote arduino using wireless to communicate. For the box on the bike, I basically need a power supply and the ability to detect presence or absence of “12v”. According to the voltmeter in my car, my operating voltage varies from 11.8 to 15.6v, so clearly I need to limit and regulate this somehow.
I’ve read about adding a voltage regulator and caps for the power supply, but doesn’t anybody make a commercial all in one unit that can take say, 7-20v in and give me a smooth 5v? I’d rather spend $20 on something like that than mess sound soldering and then packaging everything up so that it’s waterproof, adequately cooled, etc.
Secondly, what’s the best way to reliably and safely detect presence or absence of four individual 12v signals? Again a commercial component is more than acceptable/preferable.
Thanks in advance
mark
I’m confused. You intend to have an Arduino on the bike ? It’s intended that it run off the “12” V ? The Uno has a regulator onboard and should accept the 11.8-15.6V range to make it run. Why not use an Uno ? Are you looking to run something else off the regulated voltage ? If so, what ? (current requirement will dictate the answer of what to use for a simple regulator)
As for sensing the "12"V signals … are these intended to go into the on-bike Arduino ? If so why not use a voltage divider on each signal and feed them into the analog (or digital) pins ? What is the on-bike Arduino’s primary function ? Because if all it’s doing is telling the off-bike Arduino (or whatever) that those signals are present or not, then I don’t think you even need an Arduino.
Mee_n_Mac:
I’m confused. You intend to have an Arduino on the bike ? It’s intended that it run off the “12” V ? The Uno has a regulator onboard and should accept the 11.8-15.6V range to make it run. Why not use an Uno ? Are you looking to run something else off the regulated voltage ? If so, what ? (current requirement will dictate the answer of what to use for a simple regulator)
As for sensing the "12"V signals … are these intended to go into the on-bike Arduino ? If so why not use a voltage divider on each signal and feed them into the analog (or digital) pins ? What is the on-bike Arduino’s primary function ?
Thanks for reply. I must have missed something. I thought I read that continuous supply of > 12v would damage things.
The primary function is to sense conditions of the lights: brake and turn. So the on-bike arduino would sense if the light is on or off and relay that wirelessly to a remote board. My concern about a simple voltage divider is the range of voltage and noise. I guess that I could use a divider with 33% Vout to Vin ration and detect anything above 2.5 analog in as on and anything below as off. Was just wondering if there was a better way: e.g anything > 10v = on
I was editting my post above as you were typing. Let me restate what I think is an important point. If all the Arduino is doing is relaying the status of the lights; brake on/off, L turn on/off, R turn on/off and something else on/off … then an Arduino is overkill. A simple, if still overkill, alternate method would be to use an XBee series 1. IIRC they have a mode where the input on the digital inputs at the on-bike transmitter end is relayed directly to the digi outputs at the off-bike receiving XBee end. Then all you’d need is a regulator (I believe SF sells an XBee BoB w/regulator) and some input conditioning circuitry. That could be just 4 resistors and 4 zener diodes that take the 11.8+ V signal(s) and turn them into the 3.3V the XBee tolerates. And the BoB might have that circuitry already on it (or not, you’ll have to check).
What’s at the receiving end ? Is this going into a PC directly or being logged and later goes into a PC or ???
Thanks for the reply.
I saw the XBee when I was looking for wireless. I was actually planning to use Moteino - http://lowpowerlab.com/moteino/ - (about $18) with wireless included, which is half the price of the XBee1 alone (from what I can tell). I thought the XBee 1 was a shield (hope that’s the right term), e.g. it’s something that plugs into the Arduino to give it wireless capabilities. The remote end will be something that will drive some LED arrays (attached to the jacket) to replicate the lights. So it will receive messages about the state of the lights on the bike and then flash the LED arrays (probably with some kind of fancy sequencing). (I have another friend who wants something similar for his trailer.) I think I might convince him to add an accelerometer later too.
Part of the attraction for me in helping my friend out is to learn about arduino, as I have several projects at home that I could accomplish with arduino for (measuring fluid levels, contact state, etc.) and integration them into my home automation system. (Currently, I use X10 door/window sensors for them, but I want to replace these. So, I’m not too worried about overkill (on the transmitter end). What I am concerned about is power consumption on the receiver end, as it must run on batteries.
Regards
Mark
Hi Mark,
have you been able to finish this project?
What did you end up using then?
I’m about to build something very similar and my motivation is also the same as yours - to learn Arduino. Would be great if you could provide your thoughts, cause maybe I am missing something on the planning stage your thoughts would be very helpful for me!
Cheers,
Bogdan