Rak811 Trackerboard Current Consumption
I've been working with the Rak811 for a few weeks now and everything's coming along quite nicely. Using the code provided here (https://github.com/RAKWireless/RAK811_BreakBoard), I've been able to use the GPS, send and view data on The Things Network, and enter Low Power Mode.
Although I am able to enter Low Power mode, the current drawn is still fairly high. The current consumed in Low Power mode is approximately 750 microamps, or 0.75 milliamps. It's true that this is quite low, however for applications that require the Trackerboard to be powered by battery used for long period of time without recharging, 0.75 milliamps is still fairly high.
My question is, is there anything I can do to bring the current consumption down in Low Power mode? Any changes to the code I can make to shut down some additional hardware? Or any minor changes to the hardware itself to reduce the current consumed? (I've already desoldered the on-board LED's)
Any help is much appreciated
Yes, we have set up a working group on 811 Tracker low power issues, and we have found these areas that need to be modified. Can you find other places that help reduce the power consumption of the 811 Tracker?
- The R1/C1 pin of GPS power switch chip U5 needs to be connected to a pull-up circuit。
- Power indicator LED1 light removed. Reserve charge indicator, and two GPIO control status indicators.
- The EXTINT0 and ANTON pin of the GPS module needs to be connected to GPIO to facilitate wake-up in low power mode.
- CP2102 chip removed, add a serial adapter board accessories。
- Add GPIO to detect the power supply type of the device, battery-powered or USB-powered. It can be detected using the power chip PG pin and CHG pin.
- Directs one UART interface for users to expand to other devices
Thank you for such a quick and informative response! I've read about a few of these issues in other threads and it's good of you to sum them all up here for myself and others to see. I'll see if I can find any other ways to reduce the power consumed in Low Power mode. However, I lack both the time and knowledge to understand the inner workings of the Trackerboard, let alone improve upon it.
It's great they you've taken the suggestions of others to improve upon the Trackerboard. Unfortunately , I cannot afford to wait for this updated version to come out and I already own the original version. As such, I'm hoping you could supply some solutions that I could implement myself. For example, is there any way I could integrate the pull-up circuit to improve the functioning of the GPS?
Any help or suggestions would be appreciated
Edit: A few more things I'd like to ask/mention. I've found that, after turning the GPS off, LoRa packets no longer send. Does this issue occur due to the hardware issues surrounding the GPS, or is this due to something else? Also, if you're monitoring the status of the Trackerboard via a UART Terminal, upon turning the GPS off, the serial port closes itself. I'm not sure if this is relevant but I thought it was worth mentioning
We will update the reference code for a version in the near future, and may add code to turn off GPS. You can follow our github.
could you please tell me how to make this baby run at 750 microamps? What are the key changes to the original source code from Git?