Arduino Power Controller with Texas Instruments’ TPS61240

As part of my Arduino Power Controller project, I ordered and received the PCBs for the Circuits@Home boost converter utilizing the Texas Instruments’ TPS61240 chip.  My SMD soldering experience is close to non-existent, but I recently acquired a Hot Air SMD Rework Station from SparkFun.  That made soldering the converter chip possible for a mere mortal.  After building the boost converter module, I built a new Arduino power controller board utilizing the module (picture below).

Power Controller with the TPS61240 Converter

Because the TPS61240 isolates the output load when the chip is disabled, I did not need the MOSFET switch that I used in the prior Power Controller board.  As well as having that advantage, the shutdown current for the TPS61240 chip is very low.  I measured about 1.5 uA current draw of the entire power controller board when the PIC was asleep and the boost converter was disabled.

The power controller was built on a SB300 perfboard (cut with a Dremel to reduce its width).  I’ve found these to be inexpensive and effective PCBs for building one-off projects.

Below is a picture of the power controller in use controlling an Arduino with a Data Logging shield.

Power Controller with Arduino

In this application, the Power Controller periodically applies power to the Arduino + data logging shield.  While powered, the Arduino can read sensors, read the real-time clock on the shield, and then store the data on the shield’s SD card.  After doing so, the Arduino raises the power-down line back to the Power Controller and the controller removes power from the Arduino.  Multiple months of battery life can be achieved with this arrangement.

For the past month I have been measuring battery drain-down using the prior version of the Power Controller and a similar Arduino + data logging shield load.  That version of the Power Controller used a less energy-efficient boost converter.  Measurements on battery drain-down indicate that battery life should live up to the calculations presented in the prior article.

NOTE:  A commercial product is now available from Adafruit that performs this power controller task.  See the Adafruit TPL5110 Low Power Timer Breakout product.