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Post by SDL on Jul 10, 2019 14:18:10 GMT -8
Well, not much. I think that the solar system would dominate the current and you would draw very little from the USB plug.
It would be interesting to see what the SunControl board would show as far as currents and voltages. Post that if you try this.
BP
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Post by grognaak on Jul 10, 2019 16:36:00 GMT -8
Well, not much. I think that the solar system would dominate the current and you would draw very little from the USB plug. It would be interesting to see what the SunControl board would show as far as currents and voltages. Post that if you try this. BP I have to try this for my project because the 6600 mah battery I bought from Adafruit is not sufficient to cover my power needs for the main computer and sensor array. What's more, I need at least 2.1 Amps for power to my cellular communications hat, and the Pi will not provide this, so I will have solar charging the external battery pack and two USB power ports coming off to provide power to the system. One will go in the Cellular USB power in, and one will go into the SunControl board. I have two pressing design problems. One problem is my desire to measure the state of this external battery pack. Some kind of USB device sitting in between would probably be sufficient if it had Bluetooth communication, but the only such device I have found is only compatible with phone apps and Windows (barf). My other design problem is that stacking my cellular shield and Pi2Grover seems to imply that serial communications will be out of the question on the Pi2Grover board. This may or may not be a big deal, as I haven't gotten into looking at that side of the equation yet. |
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Post by SDL on Jul 10, 2019 16:52:09 GMT -8
Make sure you plug us into your solutions. Sounds like an interesting problem.
You can use our INA3221 device to measured your battery current and voltage. I2C.
Not sure what you are talking about "USB between the battery".
Yes, serial comm is probably not going to work if you are using the port for the cellular modem. You can use a software serial implementation on GPIO ports if you require serial (not super fast baud rates).
BP
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Post by grognaak on Jul 10, 2019 16:57:02 GMT -8
Make sure you plug us into your solutions. Sounds like an interesting problem. You can use our INA3221 device to measured your battery current and voltage. I2C. Not sure what you are talking about "USB between the battery". Yes, serial comm is probably not going to work if you are using the port for the cellular modem. You can use a software serial implementation on GPIO ports if you require serial (not super fast baud rates). BP I was going to attempt to use the following device and hack to get data on a USB external battery that is charged with micro usb solar panel and outputs usb power to the SunControl and a cellular shield on my Pi Zero: www.amazon.com/Multimeter-Bluetooth-Current-Detector-Capacity/dp/B07DHTXDML/ref=sr_1_3?keywords=um25c&qid=1562806198&s=hi&sr=1-3github.com/smandon/rdumtoolHowever, I'm interested in the device you recommend. I understand how I would get the monitoring data to the Pi, but how do I connect USB solar panels and batteries to that device? |
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Post by SDL on Jul 11, 2019 9:10:16 GMT -8
I don't think I understand what you are trying to do. Connect USB solar panels to what device? And can you give me an example of a USB solar panel?
BP
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Post by grognaak on Jul 11, 2019 15:29:28 GMT -8
I don't think I understand what you are trying to do. Connect USB solar panels to what device? And can you give me an example of a USB solar panel? BP The Voltaic Systems 6W panels come with their regular mm plugs in addition to a micro-USB adapter. I can interface the solar panel via micro-usb to an external battery pack with two USB power output ports (2.3 A and 2.1 A). The battery pack is supposedly smart and has protections to prevent overcharging and can vary current to devices: www.amazon.com/gp/product/B00MQSMDYU/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1My intention is to use the output power from this device to provide power to the micro-USB on the SunControl board and power to the cellular shield simultaneously. The cellular shield needs a minimum current of 2.1 A to be reliable, and the SunControl / Pi Zero W cannot provide this. . . . On a different note, I'm trying to figure out how I can use something like the following to avoid any pin conflicts with the Pi2Grover and Cellular Modem boards. I have so little understanding of GPIO, so it's an uphill battle trying to make sense of how this stuff works. www.amazon.com/gp/product/B01IB7UOFE/ref=ox_sc_act_title_1?smid=A2E7RYXKRFD586&psc=1 |
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Post by grognaak on Jul 13, 2019 22:09:03 GMT -8
Is there a problem with my SunControl board? It was working until I rebooted my Raspberry Pi. I tried to restart and it wouldn't using the SunControl board--prior restarts worked fine. The Pi works okay with a wall outlet. I'm not sure what is going on here. I know that the batteries have plenty of juice--or at least I think so. It seems to turn on for just a seconds with blue lights and then bomb. I've had both an external battery pack power source (usb) and regular battery connected simultaneously. The blue LED comes on near the USB to the Pi and everything seems to be going as normal for a few seconds before it turns off.
Edit: I tried again this morning after charging batteries overnight, and at least now it seems to work again. I think I must misunderstand something about how this device is supposed to work, or misunderstand something about my equipment. I tested the current flowing through from the usb connected to an external battery pack (with a usb tester) and I was only pulling a few hundred milli-amps. I would have expected more like 1.5 A. Puzzling.
------------------------------
SunControl Voltages and Currents
------------------------------
LIPO_Battery Load Voltage : 3.95 V
LIPO_Battery Current : -144.40 mA
Solar Cell Load Voltage : 4.88 V
Solar Cell Current : -110.00 mA
Output Load Voltage : 5.16 V
Output Current : 192.00 mA
------
USB Power turned OFF
------
------------------------------
SunControl Voltages and Currents
------------------------------
LIPO_Battery Load Voltage : 3.93 V
LIPO_Battery Current : -65.20 mA
Solar Cell Load Voltage : 4.88 V
Solar Cell Current : -110.00 mA
Output Load Voltage : 5.14 V
Output Current : 268.40 mA
------
USB Power turned ON
------
My Pi Zero is crashing every 10-15 minutes, and ssh seems to bomb randomly when I run the testSunControl.py script.
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Post by SDL on Jul 14, 2019 17:46:26 GMT -8
The test Sun Control code turns the USB power on and off, so don't power your system from SunControl when you are running it. Why don't you try just running this code (which just reports the voltages and currents) and see if it changes anything. BP github.com/switchdoclabs/SDL_Pi_INA3221 |
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Post by grognaak on Jul 16, 2019 18:21:23 GMT -8
The test Sun Control code turns the USB power on and off, so don't power your system from SunControl when you are running it. Why don't you try just running this code (which just reports the voltages and currents) and see if it changes anything. BP github.com/switchdoclabs/SDL_Pi_INA3221Thanks, I'm using that script. I think I figured out just about everything that the board does and how to use it, except for one big problem I can't seem to remediate. I have noticed over several days of testing that the USB input power only seems to work reliably if there is no USB output power. When I have my Pi running (or maybe just connected), it doesn't seem to matter how much juice is coming through my external current/voltage tester. The battery will not reliably charge. It does this quirky thing where it seems to charge well for several minutes when I connect USB input power and then either give up altogether or start wavering back and forth in sort of an annoying seesaw way, despite the fact that I am measuring approximately 1/2 amp to 3/4 amp of power coming into the SunControl through the USB with my external tester. I have tried a wall outlet, external battery pack input, and two different USB cables. However, when I unplug from the USB power out on the SunControl board, the battery charges up fine through the USB power input. Is there any way I can fix this issue? I don't understand what is happening or if this is the expected behavior. By the way, this is always at night when there is no or very little solar power coming through the panel. I'm not sure if it is also a problem when there is lots of solar coming in. I'm working on a script to test if the behavior is the same when it is sunny. Thanks! |
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Post by SDL on Jul 16, 2019 18:40:21 GMT -8
The USB input does not do a great job in charging the battery. You can put a power supply running at about 5V on the Solar input to charge up the batteries at night.
BP
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