In our first tutorial on PSOC® 6 we showcased a problem while measuring current consumption of the e-ink display. The board was powered through the battery connector, and system level measurements were made. However, the idle power consumption was excessively high, which would have been expected if powered through the USB-C port that powers the entire programmer/debugger part of the board, but not to the extent seen when powering it through the Vin pins (powering only MCU and peripherals).
For this tutorial we searched for the cause of the extensive power consumption and as it turns out it was due to faulty firmware in the USB-C controller. The main problem was the fact that when we were powering it through the battery connector, the battery charger was delivering 5V to the board. The USB-C controller was then triggered into the monitoring mode checking that there was actually 5V present, trying to charge the board back, and enabling the BQ chip from TI. This led to losing the 5V generated by BQ chip itself. As seen in the previous video – Part 1, this was repeated over and over, leading to odd power consumption spikes.
The measurement in Part 1 showed only indications of the power performance of the e-ink while being updated, but not the entire story. For this tutorial we didn’t have access to any revised firmware so we had to do alternative measurement set-up to get to the power performance of the e-ink display. Check out the video to see what we did!
It’s interesting to note that the e-ink display peaks at only 16.9 mA which is better than mentioned in the Cypress tech spec (30 mA). Thumbs up!
Also note that this development kit features a non-production revision of the PSoC® 6 silicon.
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The Qoitech Team