I tried replacing those files in the variants folder but no go. My 2.9.1 has the moded #1/30 pins.h as b4.
The only one that still works and is about .03 vdc difference which is ok for my app at present but I stand on SEEED making this work like an Adafruit or Nordic reference design to be sure it’s there brew.
code below. running on dev board.
//TESTED AOK.12/15/22
// Displays Xiao Unit ID
// Xiao MAC:
// Battery Monitor.
#include <Arduino.h>
#include <Wire.h>
#include <U8x8lib.h>
//Create a instance of class
U8X8_SSD1306_128X64_NONAME_HW_I2C u8x8(/* clock=*/ PIN_WIRE_SCL, /* data=*/ PIN_WIRE_SDA, /* reset=*/ U8X8_PIN_NONE);
// OLEDs without Reset of the Display
const int ledPin = LED_BUILTIN;
int BuzzerPin = A3; //A3 , P0.29 PIN 4
int buzzer = BuzzerPin;
volatile int Vadc = analogRead(P0_31); // Xiao ADC for BATT mon.
uint8_t mac_address[6]; // MAC_address ARRAY
void setup(){
Serial.begin(9600);
delay(2000); //relax...Get Ready for serial port
Serial.println("Processor came out of reset.\n");
startsound();
setBatt();
initdisplay();
setupblink();
}
void loop(){
char buff[6];
get_id_address(mac_address);
sprintf(buff, "\nXiao Unit: %02lX%02lX\n",
mac_address[0],mac_address[1]);
Serial.print(buff);
u8x8.clearDisplay();
u8x8.setCursor(0,-1);
u8x8.print(buff);
u8x8.setCursor(6,6);
delay(2000);
char buffer[80];
char bufferu8[80];
get_mac_address(mac_address);
sprintf(buffer, "Xiao MAC: %02lX:%02lX:%02lX:%02lX:%02lX:%02lX\n",
mac_address[0],mac_address[1],mac_address[2],mac_address[3],mac_address[4],mac_address[5] ,mac_address[6]);
Serial.print(buffer);
sprintf(bufferu8, "Xiao MAC: \n%02lX%02lX%02lX%02lX%02lX%02lX\n",
mac_address[0],mac_address[1],mac_address[2],mac_address[3],mac_address[4],mac_address[5] ,mac_address[6]);
u8x8.setCursor(0,3);
u8x8.print(bufferu8);
delay (2000);
getBattery();
delay (2000);
}
//
//************************functions **********************
//
void get_unit_id(){
char buff[2];
get_id_address(mac_address);
sprintf(buff, "\nXiao Unit: %02lX%02lX\n", mac_address[0],mac_address[1]);
Serial.print(buff);
u8x8.clearDisplay();
u8x8.setCursor(0,-1);
u8x8.print(buff);
u8x8.setCursor(6,6);
delay(100);
}
void do_mac(){
char buffer[80];
char bufferu8[80];
Serial.println("");
get_mac_address(mac_address);
sprintf(buffer, "Xiao MAC: %02lX:%02lX:%02lX:%02lX:%02lX:%02lX\n",
mac_address[0],mac_address[1],mac_address[2],mac_address[3],mac_address[4],mac_address[5] ,mac_address[6]);
Serial.print(buffer);
sprintf(bufferu8, "Xiao MAC: \n%02lX%02lX%02lX%02lX%02lX%02lX\n",
mac_address[0],mac_address[1],mac_address[2],mac_address[3],mac_address[4],mac_address[5] ,mac_address[6]);
u8x8.setCursor(0,3);
u8x8.print(bufferu8);
}
void get_id_address(uint8_t mac_address[6]) {
unsigned int device_addr_0 = NRF_FICR->DEVICEADDR[0];
unsigned int device_addr_1 = NRF_FICR->DEVICEADDR[1];
const uint8_t* part_0 = reinterpret_cast<const uint8_t*>(&device_addr_0);
const uint8_t* part_1 = reinterpret_cast<const uint8_t*>(&device_addr_1);
mac_address[0] = part_1[3]; //changed from get_mac_address elements 0,1
mac_address[1] = part_1[2]; //
}
void setBatt(){
pinMode(P0_31, INPUT); //Battery Voltage monitoring pin
pinMode(P0_13, OUTPUT); //Charge Current setting pin
pinMode(P0_14, OUTPUT); //Enable Battery Voltage monitoring pin
digitalWrite(P0_13, LOW); //Charge Current 100mA
digitalWrite(P0_14, LOW); //Enable
analogReference(AR_INTERNAL2V4); //Vref=2.4V
analogReadResolution(12);
}
void getBattery(){
int Vadc = analogRead(P0_31);
float Vbatt = ((510e3 + 1000e3) / 510e3) * 2.466 * Vadc / 4096;
Serial.print("Battery Level ");
Serial.println( Vbatt, 2);
digitalWrite(LED_GREEN, HIGH);
u8x8.clearDisplay();
u8x8.setCursor(0,2);
u8x8.print("Battery Monitor");
u8x8.setCursor(6,6);
u8x8.print(Vbatt, 2);
}
void get_mac_address(uint8_t mac_address[6]) {
unsigned int device_addr_0 = NRF_FICR->DEVICEADDR[0];
unsigned int device_addr_1 = NRF_FICR->DEVICEADDR[1];
const uint8_t* part_0 = reinterpret_cast<const uint8_t*>(&device_addr_0);
const uint8_t* part_1 = reinterpret_cast<const uint8_t*>(&device_addr_1);
mac_address[0] = part_1[1];
mac_address[1] = part_1[0];
mac_address[2] = part_0[3];
mac_address[3] = part_0[2];
mac_address[4] = part_0[1];
mac_address[5] = part_0[0];
}
void setupblink(){
setLedRGB(false, false, true); // set Blue LED
delay(1000);
setLedRGB(false, true, false); // Red
delay(1000);
setLedRGB(true, false, false); // Green
delay(1000);
setLedRGB(false, false, false); // OFF
}
void initdisplay() {
pinMode(LEDR, OUTPUT); // initialize the LED pin as an output:
pinMode(LEDG, OUTPUT); // initialize the LED pin as an output:
pinMode(LEDB, OUTPUT);
pinMode(LED_BUILTIN, OUTPUT); // initialize the LED pin as an output:
u8x8.begin();
u8x8.setFlipMode(1); // set number from 1 to 3, the screen word will rotary 180
u8x8.setFont(u8x8_font_8x13B_1x2_r);
u8x8.clearDisplay();
u8x8.setCursor(0, 0);
u8x8.print("Power ON ");
}
void startsound() {
tone (buzzer, 890);
delay (220);
noTone(buzzer);
delay (20);
tone (buzzer, 800);
delay (220);
noTone(buzzer);
delay (20);
tone (buzzer, 800);
delay (220);
noTone(buzzer);
delay (20);
tone (buzzer, 990);
delay (420);
noTone(buzzer);
delay (20);
}
void setLedRGB(bool red, bool green, bool blue) {
if (!red) { digitalWrite(LEDR, HIGH); } else { digitalWrite(LEDR, LOW); }
if (!green) { digitalWrite(LEDG, HIGH); } else { digitalWrite(LEDG, LOW); }
if (!blue) { digitalWrite(LEDB, HIGH); } else { digitalWrite(LEDB, LOW); }
}
print output,
Processor came out of reset.
Xiao Unit: 53BB
Xiao MAC: 21:0E:63:78:CF:67
Battery Level 3.50
Xiao Unit: 53BB
Xiao MAC: 21:0E:63:78:CF:67
Battery Level 3.51
Xiao Unit: 53BB
Xiao MAC: 21:0E:63:78:CF:67
Battery Level 3.50
HTH
GL 
Apparently someone at Seeed marketing thought enough to say so on the second bullet point. (and you do realize if you can’t read the battery properly and reliably then battery powered is in two words is NOT REAL.
YOU notice the two biggest issues folks have on here with this chip is “Deep Sleep” and Battery power items along with mbed conflicts and incompatibilities… So it’s a GREAT product alright but ON-Going and Timely technical support and continuing Engineering is warranted at $16
