how can i program nrf52840 with 1.8V?

RE: how can i program nrf52840 with 1.8V?

huohuo0000 — Thu, 18 Apr 2019 01:34:17 GMT

OK .The problem was solved.Thanks for your help.

Best wishes.

RE: how can i program nrf52840 with 1.8V?

Jørgen Holmefjord — Wed, 17 Apr 2019 10:41:58 GMT

You can only change the voltage down by writing to UICR. To change it higher again, you need to erase entire UICR. UICR is located in flash, and flash bits can only be changed from 1 to 0 in a write operation. To turn a bit from 0 to 1 will require erasing the whole flash page.

RE: how can i program nrf52840 with 1.8V?

huohuo0000 — Wed, 17 Apr 2019 10:02:51 GMT

yes,I tried the first answer in the post. And I measured the voltage turn to 1.8V. So far so good, but the voltage stay at 1.8 no matter how I change the value REGOUT0.Maybe there should be some extra handle?

sincerely.

RE: how can i program nrf52840 with 1.8V?

Jørgen Holmefjord — Wed, 17 Apr 2019 09:06:57 GMT

Did you follow the suggested code in the post I linked? You need to enable writing in the NVMC peripheral before you are allowed to write UICR from code.

RE: how can i program nrf52840 with 1.8V?

huohuo0000 — Wed, 17 Apr 2019 02:28:19 GMT

I means that when I do that，the output voltage I measured is 3.3V instead of 1.8V. And, I did nothing before writing.

RE: how can i program nrf52840 with 1.8V?

Jørgen Holmefjord — Tue, 16 Apr 2019 09:13:14 GMT

Hi,

What is "fault"? Have you erased UICR prior to trying to write?

Please have a look at this post.

Best regards,
Jørgen