Posts in this project

Pallet Tracker - 01 - Project description

Pallet Tracker - 02 - Development environment

Pallet Tracker - 03 - Application skeleton

Pallet Tracker - 04 - PSoC6 power modes and LPComp

Pallet Tracker - 05 - Evaluating power consumption

Pallet Tracker - 06 - Indoor localization

After having a prototype will all the functionalities I need to implement indoor localization and tracking, I will now measure the actual power consumption of the board.

Let's first have a look at the power supply section of the evaluation board

Unfortunately, the board has been designed with the goal of being as easy-to-use as possible, so a 3.3V power supply has not been provided. The only way to switch the board on is to connect a 5V power supply either to the kitprog3 USB port or the MCU USB port.

Even if I did my best to follow the guidelines and best practices suggested by Cypress to save power, probably this is going to be absolutely useless with this evaluation board because there are many external components (power regulators and converters) that are always on and may consume a consistent amount of current

Current measurement points

But, I can at least check if I did a good job by measuring current consumption at any of the test points available on the board. According to the schematics, there are at least three jumpers where current consumption can be measured

J14

By means of this jumper, you can select the VCC voltage (1.8V or 3.3V) and measure the total current consumption of the PSoC6 MCU plus external components

J15

Here the current consumption of the PSoC6 MCU only can be measured

J17 & J18

Here the current consumption of PSoC6 VDDIO and WiFi Module can be measured

Measurement results

Here are the results of the measurement. All the graphs refers to the typical application cycle, namely

• hibernation
• wake-up from hibernation, scan, send scan results
• back to hibernation

For the above-mentioned test points, two measures have been performed

1. VTARG = 3.3V
2. VTARG = 1.8V

This is a table showing power consumption in different conditions

This means that, with the 25000 mAh battery I am going to use, the expected battery life while the board is in hibernation mode is equal to

25000 / 0.48 = 52083 hours = 2170 days = about 6 years

Since the active cycle duration lasts about 20 seconds, and assuming a wake-up per hour, the estimated battery duration does not change because drawing 20 mA of current for a duration of 20 seconds does not affect the average consumption over an hour