485 MarcoPolo
485 : MarcoPolo
- Author: Javier Munoz Saez
- Description: when this UART receives 'MARCO' answers ' POLO! ' , adapted from https://github.com/javiBajoCero/ttihp-verilog-template
- GitHub repository
- Open in 3D viewer
- Clock: 50000000 Hz
How it works
This is just an UART + small WS2812b single led driver copied from my old ttsky submission https://github.com/javiBajoCero/ttsky-verilog-template
Listens to ascii 'MARCO' and once detected, with 10us delay (mega fast) replies with '\n\rPOLO!\n\r' and blips the LED from red to green.
FPGA tested :)
How to test
The device will need 50Mhz clock. (provided by the RP2 )
Connect ui[0]: "uartRX" and uo[0]: "uartTX" with your favourite UART gizmo, i used my PC and FTDI FT2232HQ USB-UART bridge builtin my ArtyS7 evaluation board.
with default putty serial settings 9600 bauds 8 data bits 1 stop bit parity NONE
and type uppercase 'MARCO' trough UART RX pin you should receive a '\n\rPOLO!\n\r' on UART TX pin
Some extra debugging signals are also exposed :
- uo[1]: "baud_tick_rx" //clock for 9600*8 bauds
- uo[2]: "baud_tick_tx" //clock for 9600 bauds
- uo[3]: "trigger_send" //flank signaling the start of uart txing
- uo[4]: "uartTxbusy" //stays high as long as uart is Txing
- uo[5]: "led_data_out" //connect the single WS2812b led here.
External hardware
probably a USB to TTL dongle like CP2102, and a WS2812b led
IO
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | uartRX | uartTX | unused |
| 1 | baud_tick_rx | ||
| 2 | baud_tick_tx | ||
| 3 | trigger_send | ||
| 4 | uartTxbusy | ||
| 5 | led_data_out | ||
| 6 | 1 | ||
| 7 | 1 |