# Våg
https://wiki.seeedstudio.com/XIAO_ESP32C3_Getting_Started/

# Step 1 - Flash the device with micropython firmware
https://micropython.org/download/esp32c3-usb/
https://micropython.org/resources/firmware/esp32c3-usb-20220618-v1.19.1.bin

esptool.py --chip esp32c3 --port /dev/cu.usbmodem143201 erase_flash 

esptool.py --chip esp32c3 --port /dev/cu.usbmodem143201 --baud 460800 write_flash -z 0x0 ../Downloads/esp32c3-usb-20220618-v1.19.1.bin 

# Step 2 - Upload the BLE code
https://github.com/davmoz/pm_vanner_scale_ble/blob/master/ble.py

The BLE-class

from machine import Pin, Timer
from time import sleep_ms
import ubluetooth
import _thread
import struct

class BLE():
    def __init__(self, name):
        self.name = name
        self.ble = ubluetooth.BLE()
        self.ble.active(True)

        #self.led = Pin(2, Pin.OUT)
        self.timer1 = Timer(0)
        self.timer2 = Timer(1)

        self.disconnected()
        self.ble.irq(self.ble_irq)
        self.register()
        self.advertiser()

        self.client_connected = False

        self.value = 0

    def connected(self):
        self.timer1.deinit()
        self.timer2.deinit()

    def disconnected(self):
        #self.timer1.init(period=1000, mode=Timer.PERIODIC, callback=lambda t: self.led(1))
        sleep_ms(200)
        #self.timer2.init(period=1000, mode=Timer.PERIODIC, callback=lambda t: self.led(0))

    def ble_irq(self, event, data):
        if event == 1:
            '''Central disconnected'''
            self.connected()
            # self.led(1)
            self.client_connected = True
        elif event == 2:
            '''Central disconnected'''
            self.advertiser()
            self.disconnected()
            self.client_connected = False


        elif event == 3:
            '''New message received'''
            buffer = self.ble.gatts_read(self.rx)
            message = buffer.decode('UTF-8').strip()
            print(message)

    def register(self):

        HR_UUID = ubluetooth.UUID(0x180D)
        HR_CHAR = (ubluetooth.UUID(0x2A37), ubluetooth.FLAG_READ | ubluetooth.FLAG_NOTIFY,)
        HR_SERVICE = (HR_UUID, (HR_CHAR,),)

        SERVICES = (HR_SERVICE,)
        # ((self.tx, self.rx,), ) = self.ble.gatts_register_services(SERVICES)
        print(self.ble.gatts_register_services(SERVICES))
        ((self.hr,),) = self.ble.gatts_register_services(SERVICES)

    def send(self, data):
        if self.client_connected:
            try:
                payload = struct.pack('<f', float(data))
                self.ble.gatts_notify(0, self.hr, payload + '\n')
            except Exception as e:
                print()

    def advertiser(self):
        name = bytes(self.name, 'UTF-8')
        self.ble.gap_advertise(100, bytearray('\x02\x01\x02') + bytearray((len(name) + 1, 0x09)) + name)

The main code

from ble import BLE
from machine import UART
from time import sleep_ms

ble_obj = BLE("CPWPlus75")

uart = UART(1, 9600, tx=21, rx=20)                         # init with given baudrate
uart.init(9600, bits=8, parity=None, stop=1) # init with given parameters

while True:
    resp = uart.readline()
    if resp and len(resp.split()) > 1:
        # resp = binascii.hexlify(resp).decode()
        parsed = resp.split()[1].decode()
        print(parsed, "kg")
        ble_obj.send(parsed)
        sleep_ms(300)

# Step 3 - Pinout


# step 4 - Scale configuration