machine.UART is not support RXD irq feature, it will brings some difficulties to uart programming in some cases.

irqUART give a alternative solutionuse, it use pin irq instead of uart irq. irqUART is simple, small and fast.

irqUART may wakeup mcu from sleep mode.

1. define user RXD irq, frame irq (when needed).
2. define a uart object.
3. define irqUART object with uart, rxd pin, RXD irq, etc.
4. init uart.

• uart: uart object
• rx_pin: uart rxd pin
• rx_irq: user rxd irq, it can be None when not use rxd irq
• frame_irq: user frame irq. Frame irq will be trigger when no new data and exceeding the specified time. It can be None if not use it
• CHR_TMO: rxd irq delay (ms) after rx_pin irq, it depond on baudrate, rxbuf etc.
• FRAME_TMO: frame irq delay (ms) after last char

from machine import Pin, UART
from irqUART import irqUART

cnt = 0
def U1_RX_IRQ(t):
    global cnt
    n = 0
    while u1.any():
        d = u1.any()
        cnt+=d
        n+=1
        print('[', n, ']', cnt, d, u1.read(d))

def U1_RX_FRAME_IRQ(t):
    global cnt
    print('FRAME end')
    cnt = 0

u1=UART(1)
ui = irqUART(u1, Pin('B7'), U1_RX_IRQ, U1_RX_FRAME_IRQ)
ui.uart.init(115200)

If you use uart transmit mass data, you may need to increase uart rxbuf size to avoid data loss.

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