nicholaswilde / solar-battery-charger

:battery: A solar battery charger to charge lithium ion (li-ion) 18650, 9V, and coin batteries and Ni-MH AA and AAA batteries. :sunny:

solar-battery-charger's Issues

Update Configuration Page with ESP32

Update the configuration page with ESP32.

bq24074 PGOOD and CHG Monitoring

Evaluate the monitoring of the PGOOD and CHG pins of the bq24074 to determine the charge state. Currently, the current direction is used to determine the state.

Update Design Page

Update Design page with the following:

• Warning about boost converter being loose because only being held down by rear two pins.
• Add ESP32 feather to hardware list.

Circuit Diagram

Update circuit diagram with switch on negative side.

Adafruit 128x64 OLED Scrolling

Figure out how to implement Adafruit 128x64 OLED scrolling.

Skip ClearChannel If Sync Fails

Skip the clearing of the channel if the sync response is not okay.

Solar Panel Optimization

Optimize the solar panel design with the additional solar cells. This will most likely be limited to either the TS4056 or the Adafruit bq24074. Should the panel have two rows in series or three rows in series? Two rows will have a lower voltage but a higher amperage whereas the three rows will be vice versa. Need to remember that the max current of the bq24074 is 1.5A.

Another limitation is that if the panel output voltage is too low, charging won't commence until later in the day or not at all if there is not enough sunlight.

GitHub Action ClearChannel.h

GitHub action test does not run when merging PR when ClearChannel.h is updaed.

Battery Optimization

Optimize the battery setup to ensure that the full battery pack can be charged on an average day in the sun. This will most likely be limited to the solar panel power output and the max current of the bq24074 of 1.5A.

Schematic Update - Switch to turn off voltage divider

Update the schematic with the Feather switch to switch off the voltage divider and not short the EN pin on the feather so that the battery can be preserved by not draining through the voltage divider.

Create Sheets Template

Create a Google Sheets template for the calibration of the battery percentage.

PowerBoost 1000 Basic LBO Monitoring

When trying to monitor the LBO pin of the PowerBoost 1000 Basic with the ESP32, the red LED comes on and prevents the Feather from booting.
https://forums.adafruit.com/viewtopic.php?f=24&t=156911&p=773904#p773904

Go to sleep while charging with button press

When button A is pressed while charging, the screen turns on. However, the Feather can't go back to sleep without resetting the Feather all together which will also upload a new data point to ThingSpeak. See if the button press when the display is on and charging can put the Feather back to sleep without resetting and sleep for the time remaining in order to keep the upload interval the same.

Test BatterySense

Test BatterySense

bq24074 Dies Randomly

I've gone through two bq24074 to where it just stops charging the battery. Monitoring the LIPO pin, the voltage oscillates between 0 and 4VDC. I suspect that it is because the panel is outputting more than 1A thus frying the IC. I have since cut the 1A jumper and soldered the 1.5A. This needs to be verified by reading the current of the panel.

The two that died also had the optional capacitor installed. This may also be a culprit. Third one does not have a capacitor.

Secure Connection

Use a secure connection to ThingSpeak rather than an insecure one.

Deep Sleep After Charge

Have the Feather go into a deep sleep after a charge is complete. Currently, after a charge is complete, the Feather will wake up and go into discharge mode because current is no longer flowing towards the battery. Because the Feather remains awake, the battery is drained again. Perhaps this can be solved by monitoring the PGOOD and CHG LEDs.

Show OLED On Discharge

Show the OLED screen and don't go to sleep when discharging the battery. This can be done by long press of button on boot or auto detect the discharge.

Calibration

Add a calibration page to calibrate the battery capacities. Coulomb counting may be used for this calibration.

Permanent Board Design

A permanent board design should be implemented instead of using a breadboard. Look at KiCAD and PCBWay to design and build the board like the Sensor Playground project.

Connection timeout

At a connection timeout to wifi connection so that the battery is not drained. Can put to deep sleep again.

Inconsistent battery voltage while charging

At the middle of charging, the voltage and current start to fluctuate and the battery doesn't charge completely. May be due to the bq charger cutting off the current once the voltage goes above 4.

Settings.h

Breakout settings.h file

Multiple Sketches

Break up the sketch into multiple sketches.

https://github.com/giljr/Ardu_Serie/tree/32864312cf8b7d4717ff56ca8039ffea7e016b4a/_45_Multifile

Evaluate the use of Adafruit IO

Evaluate if it is worth it to add support for Adafruit IO.

Remove To Do Page

Remove the To Do page since GH issues are now the place to log to dos.

Percentage Calculation

Need to implement a percentage calculation. Currently, the output is 0. This used to be linear but would like to implement some other type of method such as Coulomb counting.

ClearChannel Issue

ClearChannel function seems to not be working at the moment. It causes a panic.

WiFiManager

Use WiFiManager to manage credentials.

https://randomnerdtutorials.com/esp32-wi-fi-manager-asyncwebserver/

https://randomnerdtutorials.com/wifimanager-with-esp8266-autoconnect-custom-parameter-and-manage-your-ssid-and-password/

bq24074

Test the Adafruit bq24074 to see if it's a better setup than the HiLetgo TP4056 Type-C USB 5V 1A 18650 Lithium Battery Charger Module.

Finite State Machine

https://create.arduino.cc/projecthub/tolentinocotesta/let-s-learn-how-to-use-finite-state-machine-with-arduino-c524ac?ref=part&ref_id=8233&offset=13

Create *.cpp files

Move functions from *.h files to *.cpp files.

Implement Debug in ClearChannel

Set debug to true or false which causes if ClearChannel should be printed to Serial or not.

HUZZAH32 – ESP32 Feather Board

Test the HUZZAH32 – ESP32 Feather Board that has an internal voltage reader and additional analog pins.

ESP32-S2 Feather with BME280 Sensor

Test the ESP32-S2 Feather with BME280 Sensor that has a built in temperature and humidity sensor as well as a built in battery voltage meter.

Permanent Circuit Board

Convert from using a breadboard to a more permanent board.

Google Sheet Exponential Trendline Equation

Find the exponential trendline equation via a cell calculation rather than the legend on the chart itself.

Low battery voltage causes low current recharge

It is possible for the battery voltage to dip to 1.8 VDC due to the Powerboost and the lack of a battery protection circuit. With this low of a voltage, the charging current becomes very low (~78 mA). Once the battery voltage raises above a threshold (~3 VDC), the charging current increases drastically (~500 mA).

Add Touch Wakeup

Add touch wakeup where a button is pressed while in deep sleep and the Feather displays a reading for a short period of time and goes back to sleep without uploading to ThingSpeak.

https://randomnerdtutorials.com/esp32-touch-wake-up-deep-sleep/

Don't turn on display while charging on low power

Don't turn on display while charging on low power in order to ensure there is enough power to take an accurate reading.

Add ESP32 Circuit Diagram

Add ESP32 circuit diagram to documentation.

Test VoltageReference

Test VoltageReference

Feather turns off during discharge

The Feather turns off during discharge when connected to a high current device such as a mobile phone. This may be due to the voltage drops too low during high current output which drops below the required voltage of the Feather. The Adafruit Powerboost 1000 Basic shuts down when the Feather shuts off because the EN pin on the Powerboost is not pulled high. A work around for this is to manually turn on the Powerboost with a switch that floats the EN pin. The downside is that there isn't monitoring during discharge.

One solution might be to limit the current by using the Adafruit Powerboost 500 Basic instead.

Send data to Google Sheets

Look into sending data to Google Sheets without the need of IFTTT.

• https://github.com/rickkas7/google_cloud_tutorial#%EF%BF%BCgoogle-cloud-functions-to-datastore-example
• https://docs.particle.io/datasheets/app-notes/an011-publish-to-google-sheets/
• https://github.com/mobizt/ESP-Google-Sheet-Client

Wooden Box for Solar Panel & Battery

Design and fabricate wooden boxes for the solar panel and battery.

Charge and Discharge Calculations

Calculate the charge and discharge times based on the battery size and solar panel voltage.

https://learn.adafruit.com/energy-budgets