SparkFun Forums

[Mee_n_Mac]

No flames above (OP's revised schematic) but no power either. Try this.

vibration-motor-circuit-schematic.png

@OP: And maybe read a bit of DC theory.
http://www.electronics-tutorials.ws/dcc ... dcp_1.html

[Mee_n_Mac]

You are almost there...



Right now you have both sides of the motor going to ground. You just have to move one side of the motor to the positive side of the power supply.

Watch that diode !

[RonBeyer]

Good catch, diode is backwards!

[waltr]

And the diode D9 in backwards and will always conduct when the transistor is on causing the motor to not run.
Check your schematic against the other one posted.

[huwp]

Ah! How did I miss that? lol. Okay thank you everyone for your help, I'll go about ordering stuff. Will update again when I've got something to show for this.

[waltr]

Ok. Do post back and let us know how it works.
Oh, and we do like pictures.

[huwp]

I'll certainly take some pictures! Maybe video too if I feel it's worth it.

EDIT: actually found that arduino has a separate website to sparkfun with all this info on it. Kind of wish I found that out earlier. Got the info I needed.

Battery:

LiPo Charger Basic - Mini-USB
https://www.sparkfun.com/products/10401

Polymer Lithium Ion Battery - 2000mAh
https://www.sparkfun.com/products/8483

JST Vertical Connector, connects to RAW and GND.
https://www.sparkfun.com/products/8613

The motors seem to use 75-85 amps so am I correct in thinking that 2000mAh will give something like like 20 hours battery life? How do I work out the power consumption of the rest of the circuit? The arduino specification says nothing about input current, just "MAX VOLTAGE INPUT: 16VDC"

[Mee_n_Mac]

The motors seem to use 75-85 amps so am I correct in thinking that 2000mAh will give something like like 20 hours battery life? How do I work out the power consumption of the rest of the circuit? The arduino specification says nothing about input current, just "MAX VOLTAGE INPUT: 16VDC"

That's 75-85 milli-amps (mA), where 1 mA = 1A/1000. And since the motors can't be on all the time, you can compute some time averaged amount. The current drawn by the Arduino will depend on the code running ... a total guess might be 30 mA on average.

[huwp]

Almost ready to order now. One...last.....thing.

These are the common specifications of all the lipo batteries
Standard Discharge Current 0.2C
Max Discharge Current 2.0C
Discharge cut-off Voltage 2.75 V

Max discharge means it's current can go up to twice it's mAh
But Standard Discharge Current, what does this mean? Google says nothing about it (learned a lot about batteries regardless). 0.2C, does that mean the circuit will always draw 400mA even if using less? Does it mean there's a minimum requirement of mA for the battery to work? (do batteries have a minimum operating current?)

[Mee_n_Mac]

(do batteries have a minimum operating current?)

Not really. It means that if your circuit draws 0.2C (or less) on average you won't overheat the battery and you will get the longest runtime/charge and longest life from the battery. Your peak current is < 0.2C. Circuits will draw whatever current they will, if the power source doesn't limit it somehow.