I am running into a voltage regulator issue, and I'm not really sure how to resolve it. I would really appreciate some insights from you folks :)
General Project Info
I am working on a battery-powered project that takes samples from an accelerometer and reports them via wifi at an interval.
Here is the hardware I'm using:
- ADXL335 accelerometer (analog input, operates at 3.3v)
- ESP8266 ESP-12F wifi module
- CD4051 multiplexer
- LD33v3 linear regulator connected to the battery
- 18650 Li-ion battery (rated 3.4-3.7v)
To reduce power consumption, I'm using the ESP as a microcontroller rather than arduino. The ESP-12F has a single onboard ADC, so a multiplexer is used to cycle through the three analog axes from the accelerometer.
The problem i'm running into is that the voltage output of the LD33v3 linear regulator appears to fluctuate dramatically. The analog outputs from the accelerometer ends up being very inaccurate as a result!
I've run a few tests to isolate the problem, and here's what I've come up with. Using an arduino uno to test, if I plug the accelerometer directly into the 3.3v output the accelerometer will report stable results. If I plug it into the 5v however, and use the LD33v3 regulator to produce a 3.3v output, the results become unstable. I'm fairly sure that this is the point of failure, but I'm a bit lost on how to resolve it!
Since the ESP12F doesn't have an onboard regulator, I need to pull down the battery's voltage myself and can't use the working output from the Uno in my project. I'm fairly new to electronics so maybe I'm missing something important, so I would really appreciate some help.