uart txes, now to catch

rp2040_uart/2024-03_rp2040-uart.md

rp2040_uart/code/uart_pio/uart_pio.ino

rp2040_uart/images/2024-01-03_uart-tx-10mb.png

rp2040_uart/images/2024-01-03_uart-tx-15mb.png

rp2040_uart/images/2024-01-03_uart-tx-1mb.png

rp2040_uart/images/2024-01-03_uart-tx-20mb.png

rp2040_uart/images/2024-01-03_uart-tx-25mb.png

rp2040_uart/images/2024-01-03_uart-tx-2mb.png

rp2040_uart/images/2024-01-03_uart-tx-2p5mb.png

rp2040_uart/images/2024-01-03_uart-tx-30mb.png