Unable to change VDD to 1.8V

RE: Unable to change VDD to 1.8V

Jørgen Holmefjord — Thu, 01 Nov 2018 14:21:44 GMT

That's great! I just wanted to add the warning in case anyone else came over this thread and tried this procedure, without access to a debugger.

RE: Unable to change VDD to 1.8V

Mgiger — Thu, 01 Nov 2018 14:19:35 GMT

Hi Jorgen

Thank you for the follow up. I have also recognized this. But as i now have the connector on the dongle this doesn't matter for me.

Regards

Marcel

RE: Unable to change VDD to 1.8V

Jørgen Holmefjord — Thu, 01 Nov 2018 14:14:56 GMT

WARNING: If you follow the suggestion from michel_93, you will erase the BOOTLOADER address from UICR and you will not be able to flash the Dongle from nRF Connect through the USB port, you will require a debugger connected to the SWD interface.

If you want to erase the UICR in code to update a value, you should read every register in UICR and write it back after erase to make sure no data is lost. At the very least, you need to write back the BOOTLAODER address located in register NRFFW[0].

RE: Unable to change VDD to 1.8V

Mgiger — Thu, 01 Nov 2018 14:11:20 GMT

Hi Michel

It worked exactly as described. I have programmed the dongle over the P1 connector on the back with a nrf5280-DK. The VDD_OUT Pin is now on 1.8V as expected.

Thank you

RE: Unable to change VDD to 1.8V

michel_93 — Thu, 01 Nov 2018 13:41:57 GMT

Hi,

I have found a solution for this problem by adding the following functions to the main of the blinky example.

/**
 * @brief Function to erase UICR Registers.
 */


void nvmcErase(void)       
  if (NRF_UICR->REGOUT0 != UICR_REGOUT0_VOUT_1V8) 
  {
      NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Een << NVMC_CONFIG_WEN_Pos;        //erase enable
      while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}
      NRF_NVMC->ERASEUICR = NVMC_ERASEUICR_ERASEUICR_Erase << NVMC_ERASEUICR_ERASEUICR_Pos;   //erase UICR
      while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}
      NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Ren << NVMC_CONFIG_WEN_Pos;  //read only enable
      while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}
  }
}


/**
 * @brief Function for configuration of REGOUT0 register.
 */
void vddInit(void)
{
  if (NRF_UICR->REGOUT0 != UICR_REGOUT0_VOUT_1V8) 
  {
	NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Wen << NVMC_CONFIG_WEN_Pos;    //write enable
	while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}
	NRF_UICR->REGOUT0 = UICR_REGOUT0_VOUT_1V8;                        //configurate REGOUT0
	NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Ren << NVMC_CONFIG_WEN_Pos;
	while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}
        NVIC_SystemReset();                                               // Reset device
  } 
}

The first function is to clear the UICR Registers. The second one then writes the UICR with the new values.

Keep in mind to delete or uncomment the bsp_board_leds_init function in the boards.c file if you use a dongle.

Also the LEDs will not work properly if you use the dongle with 1.8V.

Regards,

Michel

RE: Unable to change VDD to 1.8V

Jørgen Holmefjord — Mon, 22 Oct 2018 12:23:05 GMT

There is no way to read the value of the register directly over the USB port, without flashing a firmware that reads the value and transmit it over USB (USB CDC/MDS examples, etc.).

Yes, the chip can be flashed using SWD interface in case of wrong values.

RE: Unable to change VDD to 1.8V

Mgiger — Mon, 22 Oct 2018 11:51:47 GMT

As long as only the right bits in NRF_UICR->REGOUT0 are erased this should result in the wanted behaviour (0xFFFFFFF0 should set VDD_OUT to 1.8V).

Is there any way to read out the NRF_UICR->REGOUT0 through the USB-Port or do i need to solder the P1 Pin Header?

According to the nrf52840_Dongle_User Guide Chapter 6.7 SWD interface I should be able to connect the dongle to a DK (Debug In) and program it over the same connector.

I assume this gives me the ability to read out the UICR and to reflash the bootloader (in case the NRF_UICR is already messed up).

Regards Marcel

RE: Unable to change VDD to 1.8V

Jørgen Holmefjord — Mon, 22 Oct 2018 09:17:29 GMT

What is the current value of your NRF_UICR->REGOUT0 register? Note that UICR is flash, and can only be written after erase. You can update the value by clearing bits, but you cannot set bitw without erasing. Erasing UICR can only be done by erasing the whole UICR area. The BOOTLOADER on the Dongle use some registers in UICR so I would not recommend erasing UICR as you risk bricking the device (the bootloader must be reflashed using a J-Link debugger).

RE: Unable to change VDD to 1.8V

Mgiger — Sat, 20 Oct 2018 11:47:06 GMT

Hi Jorgen

Thank you for the quick response. I currently program the dongle via nRF Connect v2.5.0 - Programmer(experimental)

I use the hex File that SES produced (ble_app_blinky_10059_s140.hex) and the precompiled S140 Softdevice Hex File (\nRF5_SDK_15.2.0_9412b96\components\softdevice\s140\hex\s140_nrf52_6.1.0_softdevice.hex)

If I add your Code right after (or before) the INIT() functions the VDD OUT Pin Voltage remains at 3.3V (3.3V is weird, given that the gpio_outupt_voltage_setup(), called from the leds_init(), should set the VDD OUT to 3.0V)

i tried the following additions / changes to your code, none of them had the effect i wished:

- Add NVIC_SystemReset() below

while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}

- Change the

gpio_output_voltage_setup(void)

function to the 1V8

- Changed 0xFFFFFFF8 to 0xFFFFFFF0 (as in the nrf52840_bitfields.h)

I really have no clue what else could be wrong.

Nice weekend anyhow

Regards

Marcel

RE: Unable to change VDD to 1.8V

Jørgen Holmefjord — Fri, 19 Oct 2018 13:45:18 GMT

In your case, that translates into this code:

if (NRF_UICR->REGOUT0 != 0xFFFFFFF8) 
{
	NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Wen << NVMC_CONFIG_WEN_Pos;
	while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}
	NRF_UICR->REGOUT0 = 0xFFFFFFF8;
	NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Ren << NVMC_CONFIG_WEN_Pos;
	while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}
}

RE: Unable to change VDD to 1.8V

Jørgen Holmefjord — Fri, 19 Oct 2018 13:36:52 GMT

Hi,

How do you program the application to the Dongle? The DFU process used by nRF Connect might not be able to write the data to the UICR registers. The at keywork in Keil will simply add these values to the given location in the HEX-file.

I would recommend that you write the UICR registers from the application, as shown in this post. Remember to reset the device for the new UICR settings to take effect.

Best regards,
Jørgen