RE: Using ARDUINO 4 RELAYS SHIELD with nrf52840 DK

Jared — Wed, 16 Jun 2021 12:32:29 GMT

Hi there,

[quote user=""]First aim is to work out the 5V supply. I want to use the nrf USB port to power everything. In reality I will only be using 2 of the relays (40mA per relay giving a total of 80mA) . What settings do I need to set on the board to achieve this and get %V out the 5V pin? [/quote]

The 5V from the nRF USB port is routed out to the P7 header on the DK. The only requirement is that the nRF USB port is connected and supplied. Note that the USB peripheral has a valid operating region for VBUS. You must therefore make sure that the current drawn from the supply doesn't result in VBUS being pulled under the valid operating region.

On the DK, the nRF USB port also supplies the high voltage regulator(REG0) of the nRF52840 SoC. The voltage is regulated by the first internal regulation stage REG0 and it's output is VDD. The output of REG0(VDD) can be adjusted by writing to the UICR register. VDD is also routed out to the P7 header. The maximum current that can be drawn externally from VDD is described here.

nRF52 development kit hardware files.

best regards

Jared