Help needed with troubleshooting

[SFC]

I hope a few veterans can help this newbie iron out some issues. I';ve searched a lot on this forum, but am unable to find the answers I';m looking for  .

I have a Crius AIO Pro v2.0 (clone, with the ';upgraded'; baro), running MPNG 3.0.1 R4 (flashed with flash tool). I use a 4-in-1 ESC, 980KV motors with 1047 props powered by a 3S 4000 mAh LiPo. My transmitter is a robbe Futaba FX-18 (yes, oldschool 35 MHz  ) and the receiver is a Corona dual conversion synth. My GPS unit is a NEO-6M v2 (also a clone I think). 3DR Radio is on it';s way from some obscure office building in china  :lipsrsealed

The reason I chose this setup is a tight budget and the FX-18 I had laying around, saving me a chunk o'; money. And since I';m fairly new to multirotors I did not want to break the bank just yet.

First of all, I have an issue with APM Planner 2, it will not let me calibrate my old radio. It says it';s not connected or turned on. I got around this by using Mission Planner, which does see my radio and allows calibrating it. So not really a big issue, but has me wondering why. Strangely enough, when I flash the FC manually with 2.8 R3, APM Plnner 2 does see the radio, but the green bars only move in the failsafe screen. It dos show the values detected during calibration.

Second, I have no clue as to which pin I need to connect to channel 5 to set up flight modes.

And last but not least, I';m having trouble getting the GPS to work. This part needs a little explaining.
As I did not RTFM, this total noob plugged the GPS in without checking the wiring. So I might have kind of fried the GPS, but I';m not sure. Turns out the TX pin was connected to 5V I since corrected it, and when I power up my drone to be, the green C led starts blinking as if it sees the GPS (though the led on the GPS itself remains awfully dead). Also Mission Planner sees a GPS without a fix. So I hope it';s not entirely wrecked.
I also soldered a longer wire to the GPS antenna, for my GPS box on a stick only has room for the antenna itself.
But no matter how long I place it with a view of the skies above when powered, I can';t get a GPS fix. So I have to rule out a few things. It could be the cable I soldered, but don';t know how to check if this is the cause. I ordered a FTDI to USB board, so I can check the unit itself with the Ublox software, but have no clue how that will work.

Can anybody give me some tips on troubleshooting the GPS while I wait for parts to arrive?
Also, I flashed the AIOP using RCTimer Crius V2, APM:Copter - Quad, Regular PWM on A8 MultiWii, UBLOX at 38400 baud. Is this correct? I calibrated this setup with Mission Planner and gives no faults, and a (tied to a) bench test confirms all controls work as they should. Any tips on what to pay attention to would be appreciated.

Cheers

[pheasant_plucker]

Have you got the RX and TX wires crossed over on the GPS?

RX to TX so one sends the other receives it.

Channel 5 on the Crius just plugs in to whatever receiver channel corresponds to a multi-position switch you want to use on your Transmitter

Gerry

[hoverfly]

A quick way to check the GPS is open the  mission planner terminal if it is working you will see a load of alphabetical spaghetti.

[SFC]

Have you got the RX and TX wires crossed over on the GPS?

RX to TX so one sends the other receives it.

Channel 5 on the Crius just plugs in to whatever receiver channel corresponds to a multi-position switch you want to use on your Transmitter

Gerry

Yes I did, I tried both options, TX to TX & RX to RX as well as crossed. That';s how I initially found out the GPS might not be fried. With a crossed connection led C on the AIOP flashes, when connected straight it doesn';t flash.

And about channel 5, I can';t find it on the Crius :embarrassed. In the Guide I found here on the forum pins A12 through A 15 are the aux connections, specifying A12 and A13 are normally ch. 6 and 7 on receiver. And as I understand A14 and 15 are for gimbal control.
So where';s ch. 5? Or can I just use any aux pin for any channel? So I could connect A12 to ch. 5 on the receiver which is my 6 position dial on the radio, and say, pin A15 to ch. 6 which is the trigger to communicate with the Death Star?

A quick way to check the GPS is open the  mission planner terminal if it is working you will see a load of alphabetical spaghetti.

That';s a good one, never thought of that. Thanks.

[SFC]

I think the GPS is fried. When I run a baro test in terminal I see lots of numbers scrolling by and blowing on the baro changes numbers, so I figure that works.
But when trying GPS test, no numbers scrolling..  Not even a zero..

So I guess it';s safe to say the GPS is no more?

[SFC]

Well, I ordered a new GPS module, which is already on its way.

Since I also have an I2C NAV module laying around, I was thinking if it made any sense using it. I figured it would, but need a bit of imput from the veterans again  .

I figured using the I2C socket on the AIO Pro would free up the Serial port for dedicated telemetry use.
I also figured since the I2C NAV module uses its own ATMega 328P Microcontroller, it would free up computing power on the AIO pro.
Using the I2C module I could set the GPS baud rate to 115200 and refresh at 5Hz.

Does the above make sense? Is it useful? Would it work?

[SFC]

While waiting for the new GPS unit to arrive, I found a USB/TTL adapter in my parts box. I wasn';t sure if the PL2303 chip was compatible but decided to have a go with it.
Turns out it was able to communicate between the GPS and U-Center 
So I used the config file I found elsewhere on this forum and uploaded it to the GPS.

Without counting on it to do anything, I plugged it in, and placed the quad near a window.
To my amazement the green light on the FC stopped blinking, then I noticed that the light on the GPS showed a steady slow blink..

I rushed to the computer to hook it up and fire up MP. It..it..it works! 
Which means I ordered a new one for nothing

Oh well, on to the next part: PID tuning   I found a few tutorials/topics about it, but they all talk about tuning Acro first. But I don';t intend to use Acro mode, so should I just tune Stabilize and Alt Hold?
Somehow my tuning screen in MP seems different form the ones I found in topics.. 

[SFC]

I dragged the drone out to the park today for some flight tests, my six year old son watching every step. But it did not want to fly straight, it flew like a motorbike with a tankslapper. :huh After two broken props I took it back inside and after some careful examination I found what was wrong. PID tuning has to wait, one of the motors has a bent shaft 

I couldn';t put my finger on why this happened..did I overlook it before.. Nope, I did test flights and it didn';t show. Then it hit me. A while back one of our cats tried to jump onto the table and was rather surprised the spot he had gauged carefully to land his jump was occupied by some odd looking thing with four arms..
I thought only a propeller had broken, but it seems the involuntary landing of the quad after meeting the cat was probably right on one of the propeller bullets..