A new era, a new beginning

It's been a while since my last post. The main cause is that I felt the energy drain as the fall gets more visible with worse weather, not too encouraging for quad flights. The darkness is also upon us, which makes flight difficult if it's not during day time.

As I've previously written, I ordered the radio telemetry, which I now got working. No hassle, it worked instantly. The only fault I did was to not turn down the COM-port speed from 115k to 57k, there after it worked as a charm :). The picture displays how the flight controller is connected to the laptop and Mission Planner using the radios. The radios are basically a wireless serial port.

 

Next, I focused on the darkness or rather how to fly when it's not full day light. Dusk has previously also been a hassle but these lights should mitigate that obstacle. Looking close at the picture below you can see how I wired the break out wire directly to the power distribution board. The board has tiny connectors all over, which allows soldering and therefore can provide extra connectivity as these lights require 11V.

 

Now to the final product, I started putting the quad back together, putting the lights in place. Hope this can light up any future winter flights.

I decided to go with green on the front and red on the back. Traditionally you should have green to the left and red to the right, but that doesn't help me when I usually see the quad from behind. Therefore I went with red to back and green up front.

 

One wire too short

I've been assembling the quad today and it turns out that I'm one wrote too short, or actually a few too short. The wires from the ESC's that are to connect to the power distribution board are a few centimeters too short... This means I need to solve that before there will be any flying :(

No success without a little ooops!

Progress! I've got both radio modules talking to each other after flashing with the openLRSng firmware. I actually didn't do any changes to the default settings and it compiled without any issues. The upload of the firmware however was a bit complicated.

As I mentioned in a previous blog post, I bought a USB serial converter called CP2102. What I probably should have bought was a FTDI adapter. This adapter has a pin called DST, which is needed to auto reset the target board when the new firmware has been transferred. The CP2102 however does not provide easy access to the DST pin. The solution was, as many others have done is to do a make shift soldering on the USB adapter in order to provide access to the DST.


And, first off, I cannot take credits for this tiny soldering. It's been done by a another guy who is far better than me. The solution consists basically of connecting pin 28 from the chip in the middle to output on the RST pin. A resistor was also removed to break the RST connection to not get double signals. I actually removed the resistor and made the other soldering, which probably was way easier. Soldering the wire to the 28th pin of the chip had to be done under a microscope :).



So, now we've got a working radio link that I've verified to provide signals that work as intended. The picture below shows how I've connected the radio receiver to the power distribution board, which also connects to one of the ESC's that connects to one of the motors. I'm now in the process of programming and calibrating the ESC's. This is needed to ensure that all motors behave in the same way and provide the correct amount of power given the throttle.

Todays ooops! happened when I by accident short circuited the battery and left some ugly marks. I should have put shrink tube on the soldered connectors of the power distribution board before playing with it, but I didn't :[.

Fixing up the power distribution board

Today was a day of soldering. Two tasks had to be performed to make the power distribution board work as intended. First off, it's connectors were incompatible with the connectors of the battery pack. That was solved by cutting away the TX60 connector and soldering a pair of 5.5mm gold connectors instead.

You can spot the old yellow TX60 connector up in the top right corner of the picture. New connectors were soldered after some trouble with the thicker soldering tin I bought today. I bought 2mm soldering tin, which turned out to be a pain to use as it took quite a bit of heat to melt. I ended up using thinner soldering tin instead.

Thereafter, I soldered the uBEC current converter onto the auxiliary power connectors on the power distribution board. The uBEC is intended to connect the power distribution board to the flight controller. As of the specification, the flight controller may switch anything from 5 to 12v but forum posts recommend using an external uBEC instead as overheating then only destroys the uBEC and not the entire flight controller.

The picture above shows the uBEC soldered to the power distribution board's aux connectors as well as the new 5.5mm gold connectors.

I've also soldered another ESC today with the same amount of success as the last one. Think I'll do another one tonight. Next question is, how do I bring voltage to the radio receiver? Not figured that one yet, stay tuned.