Solar Charger for Particle Boron With Cat M-1 Jacob Hertz January 24, 2019 All, DIY The Particle Boron is a new cellular modem for IoT. It is designed to consume less power than its predecessors, especially during data transmission. The Boron introduces Cat-M1 cellular technology, which is compatible with the existing LTE network and has an extremely low transmit power of 20dB. I measured power consumption and current draw of the setup during different transmission modes and in sleep. My results are summarized below, but the bottom line is that the Boron consumes significantly less power than the Electron in both transmission and standby. However, there still seems to be some issues with charge rates directly from solar and the sleep modes. Particle Boron Power Consumption For the power consumption test, I created a motion detection setup using the Particle Boron, an HC_SR04 Ultrasonic Sensor and Voltaic Systems V15 Battery Pack. Using a USB multimeter, I manually recorded current draw and power consumption during each mode and task. My code can be found on Github. Mode Current (A)* Power (W) Execution Time (s)** Watt Hours per Transmission (W*h) Publishing to Particle Cloud 0.09 0.41 0.001 0.000000114 Publishing to ThingSpeak 0.12 0.56 2.408 0.000375 Sleep Mode (system.sleep() ) 0.02 0.05 NA NA Standby Mode 0.02 0.10 NA NA *This was measured by executing a while loop in software consisting only of transmissions and reading the USB multimeter for the duration of the loop. **This was measured using software timers in the Particle IDE. The Boron consumes less power than the Electron (based on results here) because of a lower current draw during transmission and a much shorter transmission time. The execution time is astonishingly fast to the Particle Cloud and means that you can transmit far more often without much battery drain. The 20mW consumption standby mode also better than the Electron. We are looking forward to firmware updates to improve that performance without adding additional circuitry. It is important to note that these tests are the results for when the Particle is powered by the Voltaic power bank with no LiPo connected. With the LiPo connected, the system drew up to 3 Watts in order to recharge the LiPo. I wanted to know the amount of power needed to simply operate the Boron without recharging the battery, which is why my tests above do not include the LiPo. Charging Particle Boron from Solar On a perfectly sunny day (roughly 1,000 W/m^2), I connected the 3.5 Watt panel to a the Boron with a partially full LiPo. The panel is rated for 6 Volts @ 550mA. We maxed out at 340mA where we would expect to see closer to 450 to 500mA in real world conditions. Voltage (V) Current (A) Power (W) 4.76 .34 1.61 While this is ok, there is definitely room for improvement. For efficient charging from solar, we would recommend either: using a battery pack like Voltaic’s that is tuned to charge at a faster rate or spend time tuning the board so that it can accept the full charge rate of your panel Overall, the Boron is a huge step forward for powering IoT devices from solar power. Talk with a Voltaic expert about powering your next project off the grid. Schedule an IoT Consultation Leave a Reply Cancel Reply Your email address will not be published.CommentName* Email* Website This site uses Akismet to reduce spam. Learn how your comment data is processed.