APM 2. 5
Last month, I touched on
the APM 2. 5. The system
shown in Figure 1 consists of
the APM 2. 5+, GPS, and 915
MHz two-way telemetry radios.
In my case, I upgraded to the
better uBlox GPS unit.
You can purchase the
main unit in both side entry or
top entry for your hookup. I
prefer the top entry as it
allows for a smaller footprint
on the quad platform.
While shopping for the
APM, you may see the
nomenclature APM 2. 5+. This
just refers to the APM 2. 5,
APM 2. 5 case, GPS, and power
module. In my case, I
purchased the APM 2. 5+ set
and the telemetry radios.
One of the issues I had with the
APM 2. 5 system is that the stability of
the NAZA blows the APM out of the
water. It turns out there is a reason
for this. The firmware in the APM
was not fully utilizing the built-in
accelerometers which effectively
made the controller a three-axis
This has all changed.
With the release of the
ArduCopter 2. 9.1, the APM 2. 5+ is
now fully utilizing the accelerometers
and is now a full six-axis controller.
Does it make a difference? Yes,
While the APM is still not
on the same level as the NAZA,
it is much easier to fly and — in
my opinion — is a good
alternative to the NAZA.
In the past, I had stated
that the APM 2. 5 was a
controller that promised a lot
but delivered very little. I can
honestly say that now, I will be
utilizing the APM 2. 5 on many
of my other craft.
Why would I do this when
the NAZA is more stable, easier
to install, and requires little or
no tuning to get it to fly?
There are two reasons. I
can get an APM 2. 5 with GPS for as
little as $179. The NAZA with GPS
will run you $399. Is the NAZA twice
as stable as the APM 2. 5? Probably.
However, the cost is not the only
reason. It's all about those promises
that the APM 2. 5 makes.
FYI ... that is my house and
truck in the satellite view shown in
Figure 2. I am sitting in my basement
lab which is where the craft is
showing up on the map.
SERVO 04.2013 37