No power output pin

[oesh.attack (Firdaus Nugraha)]

Previously smooth-fluent. But either I incorrectly put a pin to a radio reviver or how finally pinout there is no power out…

[tatiana.andreeva]

Hi Firdaus,

Navio2 servo rail should be provided with power additionally. You can provide it with power from a UART port, for example.

[kai]

I have exactly the same problem using the python script. When I initialise a PWM on a pin and then call enable on it. It will not give an HIGH as output. It says on low.

I revisited the code an I actually wonder how:

def enable(self):
    with open(self.channel_path + "enable", "w") as pwm_enable:
        pwm_enable.write("1")
        self.is_enabled = True

code actually new on which pwm channel it has to write (HIGH) - 1. I assume it will be use the correct one because the chip was initialised with a channel.

Still I do not receive an HIGH on the + pin. I only receive the signal between GND and pwm.
So - I cannot switch on the channel.

I did some debugging and it actually initialise properly:

Enable Pin 0 /sys/class/pwm/pwmchip0/pwm0/
Enable Pin 1 /sys/class/pwm/pwmchip0/pwm1/
Enable Pin 3 /sys/class/pwm/pwmchip0/pwm3/
Enable Pin 2 /sys/class/pwm/pwmchip0/pwm2/

So you can see pin row 0 (pwm_signal, +, - | marked on the board with 1) writes a 1 on pwm0. So I assume it must be correct. The PWM on pin 0 (marked with 1 on the board) generates the expected pwm on pin 0 (marked with 1) on the board.

Has anyone an idea why?

Thank you in advance,
K

[kai]

I also just compiled the C program and I have the same behaviour. Do I expect something wrong?

Top pin is the PWM-Signal, middle Pin is +, and lowest pin is GND. So is it wrong when I am expecting a HIGH on the middle pin when I call the pwm enable?

[tatiana.andreeva]

Hi @kai,

May I ask you to run the ADC example and share the output with us?

[kai]

Hi @tatiana.andreeva,

sure.

Here is the output (normal DC on PI):
A0: 4.9410V A1: 0.0030V A2: 0.0200V A3: 0.0160V A4: 0.0180V A5: 0.0260V
A0: 4.9620V A1: 0.0120V A2: 0.0180V A3: 0.0160V A4: 0.0200V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0180V A3: 0.0160V A4: 0.0240V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0200V A3: 0.0160V A4: 0.0160V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0180V A3: 0.0180V A4: 0.0200V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0160V A3: 0.0160V A4: 0.0220V A5: 0.0260V
A0: 4.9590V A1: 0.0120V A2: 0.0180V A3: 0.0160V A4: 0.0200V A5: 0.0260V
A0: 4.9620V A1: 0.0120V A2: 0.0200V A3: 0.0160V A4: 0.0220V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0180V A3: 0.0160V A4: 0.0260V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0160V A3: 0.0160V A4: 0.0180V A5: 0.0240V
A0: 4.9590V A1: 0.0090V A2: 0.0200V A3: 0.0160V A4: 0.0160V A5: 0.0260V
A0: 4.9620V A1: 0.0120V A2: 0.0200V A3: 0.0160V A4: 0.0200V A5: 0.0280V
A0: 4.9620V A1: 0.0120V A2: 0.0180V A3: 0.0160V A4: 0.0220V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0180V A3: 0.0160V A4: 0.0220V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0180V A3: 0.0160V A4: 0.0180V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0180V A3: 0.0160V A4: 0.0240V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0200V A3: 0.0140V A4: 0.0180V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0180V A3: 0.0160V A4: 0.0240V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0180V A3: 0.0140V A4: 0.0200V A5: 0.0280V
A0: 4.9620V A1: 0.0120V A2: 0.0180V A3: 0.0160V A4: 0.0240V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0180V A3: 0.0140V A4: 0.0220V A5: 0.0260V
A0: 4.9620V A1: 0.0120V A2: 0.0160V A3: 0.0160V A4: 0.0220V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0180V A3: 0.0160V A4: 0.0220V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0180V A3: 0.0140V A4: 0.0220V A5: 0.0260V
A0: 4.9590V A1: 0.0120V A2: 0.0180V A3: 0.0160V A4: 0.0240V A5: 0.0260V
A0: 4.9620V A1: 0.0120V A2: 0.0180V A3: 0.0140V A4: 0.0220V A5: 0.0220V
A0: 4.9590V A1: 0.0120V A2: 0.0200V A3: 0.0160V A4: 0.0240V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0160V A3: 0.0160V A4: 0.0220V A5: 0.0220V
A0: 4.9560V A1: 0.0120V A2: 0.0180V A3: 0.0160V A4: 0.0240V A5: 0.0240V
A0: 4.9590V A1: 0.0090V A2: 0.0200V A3: 0.0160V A4: 0.0240V A5: 0.0280V
A0: 4.9620V A1: 0.0090V A2: 0.0180V A3: 0.0140V A4: 0.0160V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0200V A3: 0.0160V A4: 0.0220V A5: 0.0240V
A0: 4.9590V A1: 0.0120V A2: 0.0200V A3: 0.0140V A4: 0.0220V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0200V A3: 0.0140V A4: 0.0240V A5: 0.0220V
A0: 4.9620V A1: 0.0120V A2: 0.0180V A3: 0.0160V A4: 0.0220V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0200V A3: 0.0160V A4: 0.0180V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0200V A3: 0.0140V A4: 0.0200V A5: 0.0260V
A0: 4.9590V A1: 0.0120V A2: 0.0180V A3: 0.0160V A4: 0.0240V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0180V A3: 0.0160V A4: 0.0200V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0180V A3: 0.0140V A4: 0.0240V A5: 0.0240V
A0: 4.9590V A1: 0.0120V A2: 0.0200V A3: 0.0160V A4: 0.0200V A5: 0.0260V
A0: 4.9620V A1: 0.0120V A2: 0.0200V A3: 0.0160V A4: 0.0160V A5: 0.0260V
A0: 4.9620V A1: 0.0120V A2: 0.0180V A3: 0.0160V A4: 0.0240V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0180V A3: 0.0160V A4: 0.0220V A5: 0.0260V
A0: 4.9620V A1: 0.0120V A2: 0.0200V A3: 0.0160V A4: 0.0240V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0200V A3: 0.0160V A4: 0.0200V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0180V A3: 0.0160V A4: 0.0240V A5: 0.0260V
A0: 4.9620V A1: 0.0120V A2: 0.0180V A3: 0.0160V A4: 0.0240V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0200V A3: 0.0160V A4: 0.0220V A5: 0.0260V
A0: 4.9620V A1: 0.0120V A2: 0.0180V A3: 0.0160V A4: 0.0240V A5: 0.0240V
A0: 4.9560V A1: 0.0090V A2: 0.0200V A3: 0.0160V A4: 0.0220V A5: 0.0240V
A0: 4.9620V A1: 0.0120V A2: 0.0160V A3: 0.0160V A4: 0.0240V A5: 0.0280V

and with DC on Navio2:
A0: 5.0790V A1: 0.0240V A2: 2.1380V A3: 0.0000V A4: 0.0180V A5: 0.0260V
A0: 5.0970V A1: 0.0240V A2: 2.1440V A3: 0.0000V A4: 0.0240V A5: 0.0240V
A0: 5.0970V A1: 0.0240V A2: 2.1440V A3: 0.0000V A4: 0.0220V A5: 0.0240V
A0: 5.0970V A1: 0.0240V A2: 2.1440V A3: 0.0000V A4: 0.0220V A5: 0.0240V
A0: 5.0970V A1: 0.0240V A2: 2.1440V A3: 0.0000V A4: 0.0160V A5: 0.0260V
A0: 5.0970V A1: 0.0240V A2: 2.1420V A3: 0.0000V A4: 0.0220V A5: 0.0240V
A0: 5.0970V A1: 0.0240V A2: 2.1440V A3: 0.0000V A4: 0.0160V A5: 0.0240V
A0: 5.0970V A1: 0.0240V A2: 2.1440V A3: 0.0000V A4: 0.0200V A5: 0.0260V
A0: 5.0970V A1: 0.0240V A2: 2.1420V A3: 0.0000V A4: 0.0220V A5: 0.0240V
A0: 5.0970V A1: 0.0240V A2: 2.1420V A3: 0.0000V A4: 0.0180V A5: 0.0240V
A0: 5.0970V A1: 0.0240V A2: 2.1440V A3: 0.0000V A4: 0.0220V A5: 0.0240V
A0: 5.0970V A1: 0.0240V A2: 2.1440V A3: 0.0000V A4: 0.0180V A5: 0.0240V
A0: 5.0970V A1: 0.0240V A2: 2.1420V A3: 0.0000V A4: 0.0180V A5: 0.0220V
A0: 5.0970V A1: 0.0240V A2: 2.1440V A3: 0.0000V A4: 0.0240V A5: 0.0240V
A0: 5.0970V A1: 0.0240V A2: 2.1420V A3: 0.0000V A4: 0.0180V A5: 0.0240V
A0: 5.0970V A1: 0.0240V A2: 2.1440V A3: 0.0000V A4: 0.0220V A5: 0.0240V
A0: 5.0940V A1: 0.0240V A2: 2.1420V A3: 0.0000V A4: 0.0220V A5: 0.0240V
A0: 5.0940V A1: 0.0240V A2: 2.1440V A3: 0.0000V A4: 0.0180V A5: 0.0240V
A0: 5.0970V A1: 0.0240V A2: 2.1420V A3: 0.0000V A4: 0.0200V A5: 0.0240V
A0: 5.0970V A1: 0.0240V A2: 2.1420V A3: 0.0000V A4: 0.0220V A5: 0.0260V
A0: 5.0970V A1: 0.0240V A2: 2.1420V A3: 0.0000V A4: 0.0240V A5: 0.0240V
A0: 5.0970V A1: 0.0240V A2: 2.1420V A3: 0.0000V A4: 0.0240V A5: 0.0240V
A0: 5.0940V A1: 0.0240V A2: 2.1440V A3: 0.0000V A4: 0.0200V A5: 0.0240V
A0: 5.0970V A1: 0.0240V A2: 2.1420V A3: 0.0000V A4: 0.0200V A5: 0.0240V
A0: 5.0970V A1: 0.0240V A2: 2.1420V A3: 0.0000V A4: 0.0220V A5: 0.0240V
A0: 5.0970V A1: 0.0240V A2: 2.1440V A3: 0.0000V A4: 0.0220V A5: 0.0220V
A0: 5.0970V A1: 0.0240V A2: 2.1420V A3: 0.0000V A4: 0.0240V A5: 0.0240V
A0: 5.0970V A1: 0.0240V A2: 2.1420V A3: 0.0000V A4: 0.0240V A5: 0.0260V
A0: 5.0940V A1: 0.0240V A2: 2.1440V A3: 0.0000V A4: 0.0240V A5: 0.0260V
A0: 5.0970V A1: 0.0240V A2: 2.1420V A3: 0.0000V A4: 0.0220V A5: 0.0260V
A0: 5.0970V A1: 0.0240V A2: 2.1420V A3: 0.0000V A4: 0.0240V A5: 0.0240V
A0: 5.0970V A1: 0.0240V A2: 2.1420V A3: 0.0000V A4: 0.0200V A5: 0.0240V
A0: 5.0970V A1: 0.0240V A2: 2.1420V A3: 0.0000V A4: 0.0220V A5: 0.0260V
A0: 5.0970V A1: 0.0240V A2: 2.1420V A3: 0.0000V A4: 0.0200V A5: 0.0280V
A0: 5.0970V A1: 0.0240V A2: 2.1420V A3: 0.0000V A4: 0.0180V A5: 0.0220V

FYI: My result for measuring the + pin is on both power supplies the same.

[tatiana.andreeva]

@kai,

Thanks for sharing the output!

Would you mind also posting here your hardware setup photos? At the moment, it seems the servo rail isn’t supplied with the power.

[kai]

Hi @tatiana.andreeva,

Yes, I will do. I have a question. I measured the pins and I noticed all pins on the + are connected.

Is the following command supposed to switch the + pin on or is it a continues power supply.

pwm->enable(PWM_OUTPUT)

So can you explain if this is supposed to activate the pwm chip or the + pin. Because all + pins are connected so - it would not make any sense to enable a certain pin.

[tatiana.andreeva]

Hi @kai,

Usually, servo rail on Navio2 is powered from ESCs that are, in turn, powered from an external battery. By default, there is no power on the servo rail, and it’s not possible to switch it on using a command.

If there are no ESCs connected to a rail, you can also connect any of 5V and GND pins to an external 5V power source. For testing purposes, it’s also possible to power the servo rail from the Navio2 itself: from a UART port, for example.