Serial Monitor not working when my RC Receiver is plugged in

I am working on a Quadcopter based off an Arduino Zero board. I have a bunch of sensors plugged in and other devices necessary for my goal, but once I plug in my RC Transmitter to power (aka to 5v & ground), my serial monitor stops outputting data. Whether the RC Transmitter is off or on while plugged in, no data is outputted.

This makes it kind of hard to debug whilst everything is running simultaneously. Anyone have any ideas why this happens?

Sounds like your receiver is drawing too much current. Try giving it a separate power supply.

...R

I am pretty sure RC receivers ant transceivers are using serial communication and maybe the frequancy in Serial.begin() isn't matching the one you are using in the serial monitor?
Please specify what exactly is not working and post your code :slight_smile:

aradarbel10:
I am pretty sure RC receivers ant transceivers are using serial communication and maybe the frequancy in Serial.begin() isn't matching the one you are using in the serial monitor?
Please specify what exactly is not working and post your code :slight_smile:

If power (5v and GND) isn't supplied to the RC receiver by the Arduino, the serial monitor outputs data. If power is supplied, the serial monitor does not output any data. It isn't a Serial.begin() issue. It's weird, I don't remember this always being any issue.

Robin2:
Sounds like your receiver is drawing too much current. Try giving it a separate power supply.

I'll try to find a different power supply for it and update you guys.

Update-

I hooked up the RC Receiver's power to a separate Arduino Uno and the problem still occurs.

Here's some information about how the 6 channel RC Receiver is connected to the Arduino Zero and the rest of the quadcopter:

  1. 4 GNDs from the 4 separate ESCs (BECs) are connected to the receiver
  2. 1 ground wire is connected from the receiver to the Arduino Zero
  3. 4 data wires are connected from the receiver to the Arduino Zero
  4. 5V and GND wires are plugged into the RC Receiver but aren't connected to anything due the Serial Monitor issues

Any advice would be appreciated! If I did a poor job of explaining or if you would like a picture of parts of the setup, please let me know.

Thanks,
Suky

Try powering the receiver from a pack of 4 x AA alkaline cells (6v). Connect the battery GND to the Arduino GND,

...R

Robin2:
Try powering the receiver from a pack of 4 x AA alkaline cells (6v). Connect the battery GND to the Arduino GND,

...R

I tried this, same result :frowning:

The RC transmitter you linked to specs: 8 x 1.5V AA Batteries.

Are you using the batteries or some other power?

Paul

sukalo98:
Here's some information about how the 6 channel RC Receiver is connected to the Arduino Zero and the rest of the quadcopter:

  1. 4 GNDs from the 4 separate ESCs (BECs) are connected to the receiver
  2. 1 ground wire is connected from the receiver to the Arduino Zero
  3. 4 data wires are connected from the receiver to the Arduino Zero
  4. 5V and GND wires are plugged into the RC Receiver but aren't connected to anything due the Serial Monitor issues

How is the Arduino powered?

Each ESC has 3 wires. Where are the other two (Vcc and signal) connected? If your ESCs all have BECs then these may be interfering with whatever else you're using for power.

What pins are the receiver "data wires" connected to?

Steve

Paul_KD7HB:
The RC transmitter you linked to specs: 8 x 1.5V AA Batteries.

Are you using the batteries or some other power?

Paul

During flight, the RC receiver would normally be* powered by the Arduino's 5v and GND pins. The Arduino and all the other electronics would be powered by a Turnigy 2200mAh 3S 11.1V battery.

During testing, the RC receiver would normally be powered by the Arduino's 5v and GND pins. The Arduino is powered by my Macbook Pro 2015 Retina Display, which I believe has a USB 3 output of up to 900mA at 5V. But ever since this issue arose, I've tried powering it with 4 x 1.5V AA Batteries as well as using another Arduino as power sources (with no success).

Each ESC has 3 wires. Where are the other two (Vcc and signal) connected?

What pins are the receiver "data wires" connected to?

Each ESC has a BEC. Vccs on the BECs aren't connected to anything.

The data wires from the RC receiver are connected to pins 8-12 on the Arduino Zero.

If your ESCs all have BECs then these may be interfering with whatever else you're using for power.

What do you mean by this?

sukalo98:
During flight, the RC receiver will be powered by the Arduino's 5v and GND pins.

Not if it does not work like that. If it won't work when testing it won't magically start working in flight.

We seem to be going round in circles here.

In Reply #6 you say you tried batteries and they did not help. You need to make a simple pencil drawing showing how every thing was connected when using the batteries and post a photo of the drawing. See this Simple Image Guide

Also post the program you use when the batteries are connected.

...R

Not if it does not work like that. If it won't work when testing it won't magically start working in flight.

Sorry, I meant to say "would normally be" instead of "will be", if we ever figured out the issue and got it working again.

You need to make a simple pencil drawing showing how every thing was connected when using the batteries and post a photo of the drawing

By 'everything', do you mean just the connections between the RC receiver, 4 x 1.5 AA batteries and the Arduino? Or literally everything connected to my system?

sukalo98:
By 'everything', do you mean just the connections between the RC receiver, 4 x 1.5 AA batteries and the Arduino? Or literally everything connected to my system?

Everything connected to the Arduino and anything else that might have a bearing on the problem.

Apart from the Arduino, the receiver and the batteries what else is there?

...R

Everything connected to the Arduino and anything else that might have a bearing on the problem.

Apart from the Arduino, the receiver and the batteries what else is there?

Okay, here is a diagram for all the devices and parts in my quadcopter project. If there are any errors, please let me know. I may have miswritten something on the diagram or the actual connection on the drone is wrong and i'll verify it.

sukalo98:
Okay, here is a diagram for all the devices and parts in my quadcopter project.

Sorry but it would take me far too long to make any sense of that diagram.

Can you not just make a simple diagram with lines showing which pins are connected to which?

It would also probably make sense to set up a simple test with nothing connected to the Arduino except the receiver that seems to be causing the problem.

...R

The arduino Zero operates at 3.3V . Don't know if the pins are 5v tolerant but if you are hooking up to an R/C

receiver(most operate at 5V) then that might explain the lockup.

Just wondering if this is relevant.

Section ...... under Note......

This board is different: when the Zero is connected through the Programming Port and you open the Serial Monitor, the board does not automatically reset and the sketch loaded keeps running. To restart the sketch you need to press the reset button on the board itself.

Also, esc units can be noisy and possibly upset the uC if on the same power line as you have.

Can you not just make a simple diagram with lines showing which pins are connected to which?

I initially started doing this but I thought it looked too messy. But if it's easier to read, here you go. Excuse my poor handwriting.

But I think I narrowed the issue?

Looking through my replies, I forgot to mention (I apologize) that I am using an XBee shield with an XBee radio module attached to communicate with other modules. This shield, alongside the radio module, uses UART communication to talk to the Arduino Zero board (aka the RX and TX pin). This is how it looks plugged-in to the Arduino.

It would also probably make sense to set up a simple test with nothing connected to the Arduino except the receiver that seems to be causing the problem.

I ran some tests to see what combinations of having the ESC BEC pins, RC receiver pins and powering the ESCs with the 11.1v battery would allow the Serial Monitor to output data. It turns out, when I took the XBee shield off (and plugged pins directly to the Arduino Zero), every combination of having everything plugged-in worked. But, when the shield was plugged-in, the Serial Monitor did not output data when the ESC BEC pins and RC receiver pins were connected simultaneously, unless the 11.1V battery was plugged into the ESCs. Every other combination worked though.

So, this is a circuit problem through the ESCs?
Or, the XBee UART communication is interfering with the Serial Monitor data?
Or both? Not exactly sure, any advice would be appreciated.

It sounds like it is something to do with the internal wiring in the XBEE shield.

the Serial Monitor did not output data when the ESC BEC pins and RC receiver pins were connected simultaneously, unless the 11.1V battery was plugged into the ESCs.

That sounds as if you have a solution.

Another thought, do you really need the BEC pins connected - as it sounds like it works when they are not connected.

My feeling is that this is just too complex to figure out over the internet unless you are lucky to make contact with someone who has the exact same equipment.

...R

That sounds as if you have a solution.

Another thought, do you really need the BEC pins connected - as it sounds like it works when they are not connected.

Yeah, I'll either plug in the battery or disconnect the ESC pins while testing minuscule stuff.

My feeling is that this is just too complex to figure out over the internet unless you are lucky to make contact with someone who has the exact same equipment.

Yeah, that's understandable. I guess I'll wait until I'm back at school and ask one of my professors. Thank you for all your help though. Btw, was the second diagram readable?