How to use nRF52840-DK with an external power supply?

[eye]

Hello,

Now,in my application I use to power the nRF52840 with a 3.3V external supply at the VDD pin.

I want to know how to set it, I want to power the nRF52840 with a 3.3V external supply at P21.

It does not energize in this setting.
Is there a missing or unnecessary settings?

・SB36 -> shorted
・SB39 -> shorted
・SW6 -> DEFUULT
・SW8 -> ON
・SW10 -> OFF

Best Regard.

eye

[Jared]

Hi,

How is SW9 configured?

Best regards

Jared 

[eye]

Hi,Jared

Thank you for reply

  SW9 =>VDD

Best regards

eye

[Jared]

Hi,

The ble image transfer demo shouldn't be dependent on the power supply.

• Could you be more specific of what happens you execute the Github demo program?
• Do you measure any voltage on the VDD pin?
• What IDE are you using to program the chip?

Best regards

Jared

[eye]

Hi,

I have two boards, so I will organize them once.

[Settings with differences]

• Board_A
  ・circuit :SB40 ->cut , P22 -> shorted
  (I was trying to use for comparison of voltage.I used it when I asked a question)
•  Board_B
  ・circuit :default. it's not modified at all
  (New! I prepared to compare the action)

[Common settings]

• IDE: SEGGER Embedded Studio for ARM 4.16
• SDK:nRF5 SDK ver15.3
• program: nrf52-ble-image-transfer-demo
  => The code has been modified by the SDK version upgrade.
  (nrfx_power_clock.c -> nrfx_power.c)
• Camera: Arducam Mini 2MP camera module (OV2640)
• Camera's Wiring: I reference GitHub's readme.

-------

Q1) Could you be more specific of what happens you execute the Github demo program?
A1) Board_A and Board_B do the same action

 [OK] VIN3-5V(3.3V)  / J2.USB connector(5V)

1. Energize at 220mA.
2. LED_1 Keep on flashing.
3. Android_App can scan Board with BLE5.
4. Android_App can connect Board with BLE5.
5. Android_App can take camera's pictures and stream.

[NG] P21.eternal supply(3.3V) / Coin cell battery(3.0V)
=>  Do not energize

--

Q2) Do you measure any voltage on the VDD pin?
=> No. Board_B's circuit has not been modified at all.

However, when measuring the voltage on the Board_A, it is the same as the A1.

--
Q3) What IDE are you using to program the chip?
A3) SEGGER Embedded Studio for ARM 4.16

Best Regards.

eye

[eye]

I checked additionally

 P27.Li-in connector(3.3V) 

=>  OK

I think so, It is effective only when using 5 V power sources.

eye

[Jared]

Hi,

What power source are you using when it's not working? 

eye said:

 P27.Li-in connector(3.3V) 

=>  OK

Does this mean that it worked with the Li-Po battery connected to P27?

Best regards

Jared

 

[eye]

He, Sorry for the late reply.

> What power source are you using when it's not working? 

I usually use VIN3-5V .

But , When measuring current,　　It is not recommended.



>Does this mean that it worked with the Li-Po battery connected to P27?
Yes.　
Instead of the　Li-Po　battery, P27 was powered by supplying 3.3 V from the regulated power supply.


Best regards.

eye 

[Jared]

Ok, i'm not sure I understand. It worked with the Li-Po battery connected to P27, but did not work with external supply connected to P20?

[eye]

Hi,

> It worked with the Li-Po battery connected to P27

=> Yes.It worked.

---

> did not work with external supply connected to P20?

with external supply connected to P21

=> It did not work.

---

with VIN3-5V  connected to P20

=> It worked.

---

Best Regards.

eye

[Jared]

Ok. This is probably due to the power requirements of the application. What external power source are you using on P21? A coin cell will not deliver enough for the application to run.