USB host 5V power

[PierreMary]

Hello,
I try to power a speaker with the teensy's usb host.
But when I connect it nothing happened & with my multimeter I don't find 5V output.

So what is my mistake please ?

 

[Frank B]

Hello,
I try to power a speaker with the teensy's usb host.
But when I connect it nothing happened & with my multimeter I don't find 5V output.

So what is my mistake please ?

The power needs to enabled.
The USBHost library does that.

 

[Frank B]

...but it cannot deliver much power. Might be not enough for a speaker.

 

[PierreMary]

It's 5v usb speakers, I don't find how to enable the power in the github...
https://github.com/PaulStoffregen/USBHost_t36

Do you know how ?

 

[Frank B]

I'd just look at the examples.
Not sure, but perhaps it's enough to include it and to call begin()

#include "USBHost_t36.h"

USBHost myusb;

void setup() {
...
  myusb.begin();
...

If you to enable it without using the libary, you have to to look at the code... ehci.cpp, begin()
https://github.com/PaulStoffregen/U...a8f472080c77d05ff24372436673dd2/ehci.cpp#L107

 

[Frank B]

Not verified or tested:


For Teensy 3.6 it might be this:

    // Teensy 3.6 has USB host power controlled by PTE6
    PORTE_PCR6 = PORT_PCR_MUX(1);
    GPIOE_PDDR |= (1<<6);
    GPIOE_PSOR = (1<<6); // turn on USB host power

https://github.com/PaulStoffregen/U...a8f472080c77d05ff24372436673dd2/ehci.cpp#L111

For Teensy 4.1, maybe the four lines following line 208

    IOMUXC_SW_MUX_CTL_PAD_GPIO_EMC_40 = 5;
    IOMUXC_SW_PAD_CTL_PAD_GPIO_EMC_40 = 0x0008; // slow speed, weak 150 ohm drive
    GPIO8_GDIR |= 1<<26;
    GPIO8_DR_SET = 1<<26;

https://github.com/PaulStoffregen/USBHost_t36/blob/02092fd26a8f472080c77d05ff24372436673dd2/ehci.cpp#L208

 

[Frank B]

It's 5v usb speakers,

This says nothing. How many mA?

 

[PierreMary]

Yes It works ! Thanks Frank !

 

[Frank B]

Glad it works