sandeepmistry/arduino-nRF5

NRF52 - I2C, hight power consumption after Wire.end()

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#261 opened on Mar 13, 2018

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Description

Hi, I'm using I2C in a low power solutions. I tried to disable I2C after using it but I obtain strange hight power consumption behaviour. I'm using the following code:

#include <Wire.h>

void setup() {
  // start of I2C block
  Wire.begin();
  Wire.beginTransmission(0x19);
  int8_t ret = Wire.endTransmission();
  Wire.end();
  // end of I2C block
}

void loop() {
  NRF_POWER->TASKS_LOWPWR = 1;
  __WFE();
  // Make sure any pending events are cleared
  __SEV();
  __WFE();
}

On my board the consumption with the I2C block of code is 0,78 mAh when I remove the block I obtain 0,36 mAh.

Any suggestion on how to reduce the consumption?

Contributor guide

Research direction
Investigate the Wire.end() implementation in the nRF5 Arduino core to check if the I2C peripheral is properly disabled and pins are set to low power state. Look for any missing steps that could cause continued power draw.
Tech stack
c
Domain
embedded iot
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
C
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60