Schematic
Wire up the hardware accordingly
Display UV sensor values with a LiPo
Hardware:
#include <Adafruit_GFX.h>
#include <Adafruit_SharpMem.h>
#include <Wire.h>
#include "Adafruit_VEML6075.h"
Adafruit_VEML6075 uv = Adafruit_VEML6075();
#define SHARP_SCK 12
#define SHARP_MOSI 13
#define SHARP_SS 7
#define VBAT_PIN (A7)
#define VBAT_MV_PER_LSB (0.73242188F) // 3.0V ADC range and 12-bit ADC resolution = 3000mV/4096
#define VBAT_DIVIDER (0.71275837F) // 2M + 0.806M voltage divider on VBAT = (2M / (0.806M + 2M))
#define VBAT_DIVIDER_COMP (1.403F) // Compensation factor for the VBAT divider
Adafruit_SharpMem display(SHARP_SCK, SHARP_MOSI, SHARP_SS, 144, 168);
#define BLACK 0
#define WHITE 1
void setup(void)
{
Serial.begin(9600);
// initialize display
display.begin();
display.clearDisplay();
// initialize uv sensor
if (! uv.begin()) {
Serial.println("Failed to communicate with VEML6075 sensor, check wiring?");
}
Serial.println("Found VEML6075 sensor");
readVBAT();
}
void loop(void)
{
int vbat_raw = readVBAT();
uint8_t vbat_per = mvToPercent(vbat_raw * VBAT_MV_PER_LSB);
float vbat_mv = (float)vbat_raw * VBAT_MV_PER_LSB * VBAT_DIVIDER_COMP;
Serial.print("ADC = ");
Serial.print(vbat_raw * VBAT_MV_PER_LSB);
Serial.print(" mV (");
Serial.print(vbat_raw);
Serial.print(") ");
Serial.print("LIPO = ");
Serial.print(vbat_mv);
Serial.print(" mV (");
Serial.print(vbat_per);
Serial.println("%)");
display.setRotation(0);
display.clearDisplay();
display.setTextSize(2);
display.setTextColor(BLACK);
display.setCursor(10,10);
display.println("UV index");
display.setCursor(10,30);
display.println(uv.readUVI());
display.setCursor(10,65);
display.print("UVA ");
display.setCursor(10,85);
display.println(uv.readUVA());
display.setCursor(10,120);
display.println("UVB");
display.setCursor(10,140);
display.println(uv.readUVA());
display.refresh();
delay(1000);
}
int readVBAT(void) {
int raw;
// Set the analog reference to 3.0V (default = 3.6V)
analogReference(AR_INTERNAL_3_0);
// Set the resolution to 12-bit (0..4095)
analogReadResolution(12); // Can be 8, 10, 12 or 14
// Let the ADC settle
delay(1);
// Get the raw 12-bit, 0..3000mV ADC value
raw = analogRead(VBAT_PIN);
// Set the ADC back to the default settings
analogReference(AR_DEFAULT);
analogReadResolution(10);
return raw;
}
uint8_t mvToPercent(float mvolts) {
uint8_t battery_level;
if (mvolts >= 3000)
{
battery_level = 100;
}
else if (mvolts > 2900)
{
battery_level = 100 - ((3000 - mvolts) * 58) / 100;
}
else if (mvolts > 2740)
{
battery_level = 42 - ((2900 - mvolts) * 24) / 160;
}
else if (mvolts > 2440)
{
battery_level = 18 - ((2740 - mvolts) * 12) / 300;
}
else if (mvolts > 2100)
{
battery_level = 6 - ((2440 - mvolts) * 6) / 340;
}
else
{
battery_level = 0;
}
return battery_level;
}BOARD?=adafruit:nrf52:feather52832
PORT?=/dev/tty.SLAB_USBtoUART
BUILD=build
# Arduino CLI version 0.14.0 is used.
.PHONY: default lint all flash clean
default: lint all flash clean
lint:
cpplint --extensions=ino --filter=-legal/copyright *.ino
all:
arduino-cli compile --fqbn $(BOARD) --output-dir $(BUILD) ./
flash:
adafruit-nrfutil dfu genpkg --dev-type 0x0052 --application $(BUILD)/*.hex dfu-package.zip
adafruit-nrfutil dfu serial --package dfu-package.zip -p $(PORT) -b 115200
clean:
rm -rf build
rm dfu-package.zipWire up the hardware accordingly