Motors, controls, and an IR question for micromouse
- Hello, again.
I've done what I can to figure things out with my team, but I've
reached a point where I'm a bit too outside my knowledge to provide
sufficient answers. The design has reached a point where we need to
start testing and characterizing the components, and I'm at a loss for
how to do so safely.
We have acquired a pair of RC car motors, INSANE 370 MLST. I can't
find any information on their current requirements/tolerances, just a
suggestion that they not exceed 7.2 V driving voltage.
What would be a good way to determine their limits without damaging them?
The batteries we plan to use are 6V Ni-MH rechargables rated for
600mAh(150) and I'm not entirely sure about what that means as far as
maximum sourcable current goes. For powering the motors, I've gotten a
MC78XX 5v Voltage regulator (1 Amp max), and will be using some caps
to limit the noise, as well as having a common ground but seperate
v-regs for the controls and the motor circuitry. Since the batteries
shouldn't supply 1 A at any point, I think this regulator should be
sufficient, but I'd like to know if I'm making an error in judgement.
We are going to use the PIC18F4431 as our controller, which is
designed for PWM. I don't think it will be able to adequately source
the current we'll need, so I'm looking for H-bridge ICs for the
Motors. Would TI's SN754410 controller suit our needs?
Is the 38 kHz receiver module that Radioshack sells a good choice for
a distance sensor, or are there other modules that would be better
suited to that task?
Thanks in advance,
- Ben Estroff wrote:
> We are, of course, going to use gearings that will make our 35-36My apologies - I rather thought you had dropped a zero.
> mm diameter wheels rotate at an appropriate rate.
have you looked here:
<shameless self promotion>
</shameless self promotion>
> On 13 Mar 2007 12:43:27 -0700, Peter Harrison <peter.harrison@...>
>> Ben Estroff wrote:
>>> I believe we'll be using three Sharp GPD120 IR range sensors.
>>> And, are these motor specs acceptable? We're hoping to have a maximum
>>> velocity of 1.6 m/sec.
>>> *MO-201 GEARBOX WITH MOTOR REVERSIBLE 12V 70RPM *
>>> Torque 2.1kg/cm
>>> Rated Voltage 12.0V
>>> Operating 4.5 - 18V max
>>> Current - No load 30mA
>>> Current - Full load 390mA
>>> Gear Ratio 82:1
>>> Shaft Speed 70RPM
>>> I'm not sure of the dimensions, but this gearhead motor should fit
>>> our desired footprint, and be much better in terms of power consumption.
>> I am sure you can do the sums as well as me but...
>> To get 1.6m/s with wheels doing 70rpm you will need wheels that are
>> 436mm diameter.
>> Pete Harrison