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Mar 20, 2017, 02:23 AM
Registered User
Thanks for the reply Sureshot Bill. I'll disconnect the white wire. I hooked everything up but no picture. Get a message" no mavlink" on screen but no cam image, two solid red on Minimosd but no flashing amber. Maybe my solder blob didn't take. That seems the trickiest thing to get a blob that will stay, i just get flux running and I don't want to leave the iron on the board because I'm afraid of burning something else up, but the led still works so I'll try some more. Thanks again for reply Sureshot.
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Mar 20, 2017, 03:16 AM
Registered User
Sorry the message is "no mav data!" so i'm thinking about re updating the CX-20 apm maybe firmware didn't take?
Mar 20, 2017, 04:37 AM
Registered User
fatquad's Avatar
Quote:
Originally Posted by budwyzer View Post
Sorry the message is "no mav data!" so i'm thinking about re updating the CX-20 apm maybe firmware didn't take?
What firmware are you running ? You need custom firmware for telemetry to work unless it is on stock cheerson firmware. If you have updated it and it's not the custom firmware it will not work.

Here is the custom if you haven't got it.
Mar 20, 2017, 07:46 AM
CX20 internals F450 frame
sureshot__'s Avatar
Quote:
Originally Posted by budwyzer View Post
Thanks for the reply Sureshot Bill. I'll disconnect the white wire. I hooked everything up but no picture. Get a message" no mavlink" on screen but no cam image, two solid red on Minimosd but no flashing amber. Maybe my solder blob didn't take. That seems the trickiest thing to get a blob that will stay, i just get flux running and I don't want to leave the iron on the board because I'm afraid of burning something else up, but the led still works so I'll try some more. Thanks again for reply Sureshot.
Since both the digital & analog side of the board have their red LEDs on, your solder jumpers are good.
Since you are seeing a screen message, the OSDs Vout is good. So now you have to verify the camera's live out is on and getting to the OSD.
MP has an OSD Enable function under the Initial Setup tab.
My OSD board has a blinking blue LED when the mavlink stream is processing.
-Bill
Last edited by sureshot__; Mar 20, 2017 at 09:23 AM.
Mar 20, 2017, 08:08 AM
Registered User
Haku's Avatar
Like a snake shedding its old skin:



IT LIVES!

Have only done a short indoor flight in stabilise, didn't even calibrate anything and it flies fine, when the rain stops I'll fully calibratte it and give it a proper flight. Now it has M8N gps

Still need to make a couple of holes for the video in & 5.8ghz antenna sockets, plus reinforce the puck but essentially it's all done.
Mar 20, 2017, 08:15 AM
Registered User
sptimmy43's Avatar
I am starting to think my s500 is cursed. Looks like 2 days of decent weather here. I get everything ready to go....front right motor wouldn't spin up. Looks like the ESC is shot. That must have happened when I had my ESC signal wires in the incorrect order and the quad flipped. Of course, I was trying new things and had mot_spin_arm set to .1 so it was trying to spin the prop into the ground. Anyway, changed mot_spin_arm back to 0 and ordered a new ESC.

Yep, for anyone keeping score my foot is in my mouth, now, too. I am pretty sure it was me carrying on about how silly it is to solder bullets on to ESCs/motors. Now I need to replace an ESC and it won't be as simple as unplugging one and plugging in another. Hopefully this is a rare occasion.

You know what!? My s500 is cursed....to have me as its owner.

Sorry for the rant. As fun as this hobby is it can be terribly frustrating.
Mar 20, 2017, 08:16 AM
Registered User
sptimmy43's Avatar
Quote:
Originally Posted by Haku View Post
Like a snake shedding its old skin:



IT LIVES!

Have only done a short indoor flight in stabilise, didn't even calibrate anything and it flies fine, when the rain stops I'll fully calibratte it and give it a proper flight. Now it has M8N gps

Still need to make a couple of holes for the video in & 5.8ghz antenna sockets, plus reinforce the puck but essentially it's all done.
Nice work!
Mar 20, 2017, 08:54 AM
Registered User
Quote:
Originally Posted by sureshot__ View Post
These pictures from my mod 2 years back.
Or you could do this - might just be enough for most gimbals depending on the ground you are taking off from.

https://hobbyking.com/en_us/extended...ing-skids.html
Mar 20, 2017, 08:55 AM
Cx20,solo,x5c,ladybird,pi xh
Squirrel_D's Avatar
Quote:
Originally Posted by sureshot__ View Post
I think you're seeing the same thing I am.
My Tx & Rx are controlling the gimbal tilt using PPM through the Arducopter FC.
As soon as the mission gets to the DO_SET_ROI, I loose the gimbal tilt control from the Tx.
I suspect the ROI altitude parameter rules, but I still haven't figured out what value gives what angle.
-Bill
Hmm. Now that you say that I do remember your posts. Are you trying it I stock apm or pix*?

I'll have a read through the process but I figured the height of the roi would be used to calculate the required angle based on copter position, height, etc.
Mar 20, 2017, 08:55 AM
Registered User
Quote:
Originally Posted by Quad808 View Post
Not at all. This is one of the best and easiest mods to do to help prevent tipping forward or backward on landing.

Whoever decided to design rounded skids is an idiot. What were they thinking??
They were thinking Heli skids and horizontal relative motion (front/back) on landing. Pointy skids dig in and tip over more if there is horizontal motion. Vertical landing not an issue..
Mar 20, 2017, 08:58 AM
Registered User
miklav's Avatar
Hello everybody. First of all many thanks for this thread - I found tons of useful information here. I keep reading it page by page because it's interesting read; but I noticed when I had a specific question related to CX-20 I often ended up being pointed by google to a post within this same thread.

And now my long story.
I got interested with quad copters several years ago when it was all just starting (and ArduCopter was still using Arduino and was in it infancy and DJI didn't even exist then - it was 2011). My interest remained theoretical because I wanted to take some aerial pictures/video and it was problematic at that time. Decent action cams didn't exist; brushless gimbals didn't exist; and any decent multirotor solution was pricey as it meant to carry DSLR. So I put it on hold until some time later and focused on an RC boat model (which is almost completed but stays on a shelf for a while now).

I knew about DJI Phantom since the day it appeared on the market, but I hesitated investing into it when I never piloted any UAV other than a little kite.

The time passed on and I had other priorities in my life until last autumn. Last fall my son asked for a quad - meaning a toy grade brushed version. I ordered one as his Christmas present. When I was looking for available models I realized that decent brushless/GPS quads became much more affordable and combined with an action cam it can address my long waiting wishes in aerial pics. I saw CX-20 and I thought why not make a Christmas present to myself too ? My wife didn't object, so it was ordered from BG with a good discount at that time. I bought an action camera too.

When CX-20 arrived I unpacked it, plugged the battery and..... I heard a loud sound, smell of burnt electronics and saw a smoke coming from inside... Apparently I didn't pay attention to the wiring of the battery and it was wrong . Red and black wires were swapped (thanks Cheerson /quality control). It took a few weeks to negotiate partial reimbursement with BangGood (because their response was slow) but I must admit at the end it was generous. While waiting for emails from BG I was checking the electronics and I found that not all of it was broken. ESC-s were dead. Power board was damaged but I managed to fix it. Initially I thought FC was burnt too but it was apparently a bad contact in external USB plug and FC itself was still fine as well as motors, Rx, LEDs, GPS and compass. So at the end it was only ESCs to replace (but I already ordered APM 2.8 when I thought stock FC was burnt).

Instead of ordering original CX-20 ESCs I decided to buy little Flycolor RAPTOR 12A BLHeli units. And I got a little Arduino Nano board to configure them.

Christmas and New Year passed and it was January when I got CX-20 fixed. Then I started my flight attempts and calibration, and re-calibration and fine tuning... I had many questions but I always was able to find an answer quickly so I didn't write anything in this forum

As I was new to UAV it's very natural CX-20 was falling down many times. It's plastic body is so fragile that it got damages even falling from 1m; and a couple of times I got it fallen from 10-15m (for example one time it started to fly away fast and I was panicking and though I better drop it than loose it). During that time I had 2 decent flights and multiple short/low test/tuning flights and drops. I did glue the broken CX-20 shell every time but after all repairs it became a little shaky and one arm a little twisted...

And after all that tries it became very unstable in GPS loiter mode and I couldn't make it stable anymore (although it was fine in stabilize and in Alt-hold modes). Perhaps too high vibrations - I can't check it because CX-20 FC didn't have any data flash (or it was fried). To me that was the final stage with stock CX-20 frame.

So I decided it's a time for a new frame. As I am still new I didn't want anything fancy/expensive so I decided to go for F450. Then I thought slightly more powerful motors would be nice - so I took Racerstar 980kv from BG... and I thought APM 2.8 (which I already had) and a new M8N GPS would probably work better than stock CX-20. That means I ended up with self-made F450 quad copter, and the only few pieces from CX-20 are radio receiver, 2 LEDs, battery and battery wire with T60 plug.

I just had it assembled and did initial setup and calibration last weekend. But it's very windy the last few days so I can't fly it outdoors. Tried it indoors lifting it a few centimeters and manually adjusting INS parameters to reduce drift.

GPS is indeed much better than the one in CX-20. I've got cheap M8N and testing indoors it easily gets 12 satellites when the old one was getting 7.
And I am glad my APM 2.8 has data flash working properly.
Mar 20, 2017, 09:06 AM
Registered User
Quote:
Originally Posted by Mari C View Post
Today I had my first 4S flight with my F550 hexacopter.

The flight was good however I have to say that I was a bit nervous because of having too much power in my hands.

I pushed a bit the throttle stick my hex went up or down fastly. I like the power more than the 3S although I need to change my Pid numbers or I will have to get used to handle this 4S battery.

Now, I understand when you said to me that 4S battery is better than 3S one. I agree with all you now. Thanks.

Anyway, I had a small problem. My battery is a 5200mAh 4S 15 C Graphene. I wanted to use it until 3.3 volts per cell but when my hex had about 3.3 volt per cell, it went down fastly until 3.00 volt and less. Thanks to my hex was next to me I was able to land but now I know I can not use this battery under 3.4 or 3.5 volt per cell in my hexacopter. You can watch the log.
I am late to this conversation and all the subsequent responses from Dkemxr and Quad808 are on the ball as usual. My2c worth.

The first graph of voltage, demonstrates both the advantage and disadvantage of the graphene chemistry. Even though they are of low C rating (15 in this case). The voltage sag in flight is much reduced compared to the green Multistars. However, once they get to the end of good practice low voltage area i.e. 3.5v per cell, then the graphenes "drop off a cliff". Exactly as the graph shows.

So for all those on graphenes either as is noted here on many occasions, time your flights, monitor your mah usage or set your LVA alarm (where you can - can't on the stock CX20 LVA) to a bit above 3.5v per cell to give you some time to get home. So the landing voltage should be 10.5v (3S) 14v (4s) depending upon how much you want voltage recovery (again as in the graph) to be taken into account and how long you want the battery to last.

The more you hammer the battery the shorter it will last. The racing boys over on this thread hammer their smaller higher C batteries and most seem to be getting good longevity (considering). Just watch the cliff as the voltage gets low .

https://www.rcgroups.com/forums/show...aphene/page317
Mar 20, 2017, 09:07 AM
Mari
Quote:
Originally Posted by Mr.Jagger View Post
You have to calibrate the power module in Mission Planner in the optional hardware page.Connect the battery and measure the actual voltage when it connects and enter that value in the measured voltage field.Calibrating the mAh is fairly easy with the B6.Just measure how many mA you put back in and check that value against the CURR_TOT value.You can then adjust the AMPS PER VOLT value until the two are close to agreeing.This is best done with a freshly charged battery that gets recharged just after flight.

You should select "other" for the power module in the drop down.

http://ardupilot.org/copter/docs/com...n-planner.html

You also have a fair bit of vobration which can shake wires loose.

Using stock props the CX-20 unladen ought to hover at below half throttle.During that flight it was mostly near maximum throttle.So you are way down on power.Suspect the battery first.Test the internal resistance (if your B6 does it).Calibrate the voltage and you'll see any voltage sag during flight in the logs.And time to remount the flight controller to reduce vibration.Or check the motors for bearing failure or roughness.Something isn't right.

Only things I can find in the parameters iare these two.

COMPASS_EXTERNAL, 0 should be set to 1 - External.This will help with GPS modes.

INS_MPU6K_FILTER, 0 - Probably worth changing this to 20.It should be 20 as default which is what the 0 denotes but it sometimes gets a bit stuck.All of mine are set to 20 to avoid any problems.

The other thing you need to change for a stock flight controller are these two parameters.This should enable your power module monitoring abilities.From Tesla's blog......

For this Nova 2.52_v5.0 Flight Controller (ADC-Port Sensing pins) Parameters should be...

BATT_CURR_PIN,12
BATT_VOLT_PIN,13

https://quadcopter-robotics.blogspot...e-install.html
Hi Mr J, again,

I have low vibs in my hex now however it moves a bit in PosHold. I have watched that my INS_MPU6K_FILTER parameter is set in 0.

Should I change it to 20? Could this parameter be the guilty of my movements in Poshold?

Thanks.
Mar 20, 2017, 09:13 AM
Registered User
Quote:
Originally Posted by budwyzer View Post
Hello, trying to add Minimosd and Voltage unit to Cx-20. Have a few questions, 1) have not soldered the 5v blob on the Minimosd board yet, wondering??? to get 3dr radio telemetry (later) and Minimosd together should I leave the 12v side intact (does 12v side need to be intact to get both) ....also how do you power the 12v side (do you just run 12v to a set of pins on underside of board to the cam or the vid tx or both, sorry for dumb quiestion)? I'll add pics. (2) When opening up copter shell and doing the wire set up for the UART and battery monitor I noticed a White wire that looked broken on the board on the back side by the battery compartment and another White wire that goes to the CX-20 rx. I have put connectors on the wires and hooked them together but have not powered up copter yet just want to be sure before I power it up, but it is a white wire so don't think but not sure it will fry anything. Thanks in advance if anyone can help, Bud. (I ask this question on another thread for CX-20 but wanted to cover my bases to be safe)
I personally made the board 5v both sides (actually my board came like that). At the time there were issues with some boards overheating on the 12v side.

I then powered the Vtx as you suggested with a +12v and Gnd from the underneath pins. Still do this although I don't do OSD anymore. Taranis telemetry and the Teensy removed the OSD need for me.
Mar 20, 2017, 09:21 AM
Registered User
Quote:
Originally Posted by miklav View Post
Hello everybody. First of all many thanks for this thread - I found tons of useful information here. I keep reading it page by page because it's interesting read; but I noticed when I had a specific question related to CX-20 I often ended up being pointed by google to a post within this same thread.

And now my long story.
I got interested with quad copters several years ago when it was all just starting (and ArduCopter was still using Arduino and was in it infancy and DJI didn't even exist then - it was 2011). My interest remained theoretical because I wanted to take some aerial pictures/video and it was problematic at that time. Decent action cams didn't exist; brushless gimbals didn't exist; and any decent multirotor solution was pricey as it meant to carry DSLR. So I put it on hold until some time later and focused on an RC boat model (which is almost completed but stays on a shelf for a while now).

I knew about DJI Phantom since the day it appeared on the market, but I hesitated investing into it when I never piloted any UAV other than a little kite.

The time passed on and I had other priorities in my life until last autumn. Last fall my son asked for a quad - meaning a toy grade brushed version. I ordered one as his Christmas present. When I was looking for available models I realized that decent brushless/GPS quads became much more affordable and combined with an action cam it can address my long waiting wishes in aerial pics. I saw CX-20 and I thought why not make a Christmas present to myself too ? My wife didn't object, so it was ordered from BG with a good discount at that time. I bought an action camera too.

When CX-20 arrived I unpacked it, plugged the battery and..... I heard a loud sound, smell of burnt electronics and saw a smoke coming from inside... Apparently I didn't pay attention to the wiring of the battery and it was wrong . Red and black wires were swapped (thanks Cheerson /quality control). It took a few weeks to negotiate partial reimbursement with BangGood (because their response was slow) but I must admit at the end it was generous. While waiting for emails from BG I was checking the electronics and I found that not all of it was broken. ESC-s were dead. Power board was damaged but I managed to fix it. Initially I thought FC was burnt too but it was apparently a bad contact in external USB plug and FC itself was still fine as well as motors, Rx, LEDs, GPS and compass. So at the end it was only ESCs to replace (but I already ordered APM 2.8 when I thought stock FC was burnt).

Instead of ordering original CX-20 ESCs I decided to buy little Flycolor RAPTOR 12A BLHeli units. And I got a little Arduino Nano board to configure them.

Christmas and New Year passed and it was January when I got CX-20 fixed. Then I started my flight attempts and calibration, and re-calibration and fine tuning... I had many questions but I always was able to find an answer quickly so I didn't write anything in this forum

As I was new to UAV it's very natural CX-20 was falling down many times. It's plastic body is so fragile that it got damages even falling from 1m; and a couple of times I got it fallen from 10-15m (for example one time it started to fly away fast and I was panicking and though I better drop it than loose it). During that time I had 2 decent flights and multiple short/low test/tuning flights and drops. I did glue the broken CX-20 shell every time but after all repairs it became a little shaky and one arm a little twisted...

And after all that tries it became very unstable in GPS loiter mode and I couldn't make it stable anymore (although it was fine in stabilize and in Alt-hold modes). Perhaps too high vibrations - I can't check it because CX-20 FC didn't have any data flash (or it was fried). To me that was the final stage with stock CX-20 frame.

So I decided it's a time for a new frame. As I am still new I didn't want anything fancy/expensive so I decided to go for F450. Then I thought slightly more powerful motors would be nice - so I took Racerstar 980kv from BG... and I thought APM 2.8 (which I already had) and a new M8N GPS would probably work better than stock CX-20. That means I ended up with self-made F450 quad copter, and the only few pieces from CX-20 are radio receiver, 2 LEDs, battery and battery wire with T60 plug.

I just had it assembled and did initial setup and calibration last weekend. But it's very windy the last few days so I can't fly it outdoors. Tried it indoors lifting it a few centimeters and manually adjusting INS parameters to reduce drift.

GPS is indeed much better than the one in CX-20. I've got cheap M8N and testing indoors it easily gets 12 satellites when the old one was getting 7.
And I am glad my APM 2.8 has data flash working properly.
G'Day, G'Day and welcome to the CX20 tribe. Your path has followed the same as many others in transferring bits to another frame after questionable QC. Sounds like you know what you are doing.


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