UART connection while valid PWM signal

[r0sewhite]

Is there a way to get a UART connection to ESC32 when it already detected a valid PWM Signal (green LED solid)? In our case we can not simply remove a single PWM line.

Removing the AQ would mean that the remaining 7 ESCs don't have a powered logic part. This is okay if I just want to check/edit some parameters but if I want to run a calibration, I have to connect a flight battery and the wiki recommends to not power any ESC32 high current part unless the logic part is powered.

[chschmid]

When you power the ESC's from AQ, you are in trouble. In my setup I do not power the ESC from the FC (Vb). When attaching main power, the ESC is powerd and I can disconnect all signal wires for calibration.



Cheers
Christof

[r0sewhite]

Hi Christof,

this was no option for us because the wiki recommends to use the 5V option when running batteries >3S and our copters fly with 4S or 5S. Another reason was that configuring a fully powered ESC can be risky as long as you don't remove the props. It's safer to only power the logic side.

teramax already suggested to simply reset the mixer table to disable PWM signals, since it can easily be recovered from a file later. Anyway, maybe there is an even more simple solution.

[chschmid]

Hi Tilman

You are right. But there is no need to configure/cal all ESC's one at a time. So maybe you could do the cal with an extra set of mot/ESC and use the ESC32.txt option to configure the ESC's on your machine.

In my setup I tie the machine down, remove all signal wires and then go around with the UART if needed. But I guess since FW 1.4.3 all params can be written with ESC32.txt.

After the cal I usually attach a UniTest2 to each ESC to check for "full throttle current and behavior". I guess this is not possible with your HW or do you have some jumpers in the signal wire to select FC or external control?

Do you know the reason for not powering the ESC logic from battery @ 4s?
BTW will your board be available to buy in the near future. I would love to build a nice machine around it.

Cheers
Christof

[r0sewhite]

Okay, I am one step forward: I still had Firmware 1.4.0 or 1.4.1 on these ESCs and had the problem, that if I connect the UART to one ESC, all other ESCs were powered, too. Though all 8 logic sides together shouldn't draw more current than USB can provide, the connection failed: I wasn't able to read data from the ESC and the other 7 ESCs were also not fully powered (some LEDs were darker than others).

The solution was an update to 1.4.3: Now I can power a single ESC by UART and the other 7 ESCs remain unpowered. Obviously the 5V power is controlled by the microcontroller. This would explain why USB wasn't able to power all 8 logic sides. It was more likely the microcontroller which was overpowered. Can anyone confirm this?

So now there is at least a solution for connecting/editing a single ESC in fully assembled condition. For calibration runs I can still unset the mixer and later recover it from a file.


EDIT: Christof, I'm sorry, we will not sell the ESC boards nor the controller boards. Both PCBs will be reserved for our RTF copters.

[Kisssys]

The software change has nothing to do with the powering of the ESC's. Your probably on the threshold of being able to supply enough current.

The 5 volts supplied from the AQ at the motor connectors, the 5 volts at the FTDI connector on each esc and the 5 volts on the AQ FTDI connector are all common when the motors are plugged into the AQ.

Just remove each servo connector from the AQ and power the ESC individually from the FTDI connector or just plug one at a time into the AQ.

8 ESC's being powered by USB is close to the current limit and probably exceeds the maximum capacitance that is allowed. I do six and have had no problems but wouldn't recommend it.

[chschmid]

[r0sewhite]

[Kisssys]

Your description of the problem made me assume that are powering the esc's from the AQ with the 5volt jumper on each esc, is that not the case?

I might add that the 5volts on the AQ FTDI connector would only be connected if the Jumper 5v FTDI jumper was in fact jumpered.

[r0sewhite]

Steve, of course the ESCs are all jumpered to 5V. In normal operation they will be powered by the AQ. Since the wiki recommends to not use the Vb option when running batteries >3S, we decided for the V5 option.

I just re-checked it with another copter with the same hardware: All ESC had old firmware and I wasn't able to get a working connection. After upgrading to 1.4.3 I can either connect to the unpowered ESC and power it by UART or I can connect to the ESC of a fully powered copter and though there is a valid PWM signal, the ESC lets me read and edit parameters. All I can not do with the fully powered copter is arming by QGC (because the ESC is already armed) and starting a motor or running a calibration.