114 lines
3.4 KiB
C++
114 lines
3.4 KiB
C++
/*
|
|
* Simple USB Serial Echo Program with Timeout, Reconnect, and Backspace Logic.
|
|
* Converted to C++ so the project can use the `pico-ssd1306` C++ library.
|
|
*/
|
|
|
|
#include "pico/stdlib.h"
|
|
#include "pico/time.h" // Needed for time_us_64()
|
|
#include <stdio.h>
|
|
#include <ctype.h>
|
|
|
|
#include "hardware/i2c.h"
|
|
#include "hardware/gpio.h"
|
|
#include "pico-ssd1306/ssd1306.h"
|
|
|
|
using namespace pico_ssd1306;
|
|
|
|
// Define the maximum size for the input string buffer
|
|
#define MAX_INPUT_LEN 64
|
|
// Define the timeout period: 5 seconds in microseconds
|
|
#define TIMEOUT_US 5000000
|
|
// ASCII code for Backspace (often sent as 0x08)
|
|
#define ASCII_BACKSPACE 8
|
|
|
|
// Helper function to handle the echoing and resetting of the buffer
|
|
void echo_and_reset(char* buffer, int* index_ptr) {
|
|
if (*index_ptr > 0) {
|
|
buffer[*index_ptr] = '\0';
|
|
printf("\nEchoed (ALL CAPS): ");
|
|
for (int i = 0; buffer[i] != '\0'; i++) {
|
|
printf("%c", toupper(buffer[i]));
|
|
}
|
|
printf("\n");
|
|
}
|
|
*index_ptr = 0;
|
|
printf("> ");
|
|
}
|
|
|
|
void wait_for_usb_connection() {
|
|
printf("Waiting for USB host to connect...\n");
|
|
while (!stdio_usb_connected()) {
|
|
sleep_ms(100);
|
|
}
|
|
printf("\nConnection Established! Starting Echo Session...\n");
|
|
}
|
|
|
|
void run_echo_session() {
|
|
char input_buffer[MAX_INPUT_LEN];
|
|
int buffer_index = 0;
|
|
uint64_t last_char_time = time_us_64();
|
|
|
|
printf("--- Pico USB String Echo Program Started ---\n");
|
|
printf("Type a sentence (up to %d chars). It will echo on Enter/Timeout.\n", MAX_INPUT_LEN - 2);
|
|
printf("--------------------------------------------\n");
|
|
printf("> ");
|
|
|
|
while (stdio_usb_connected()) {
|
|
int c = getchar_timeout_us(0);
|
|
if (c != PICO_ERROR_TIMEOUT) {
|
|
last_char_time = time_us_64();
|
|
char input_char = (char)c;
|
|
if (input_char == ASCII_BACKSPACE || input_char == 127) {
|
|
if (buffer_index > 0) {
|
|
buffer_index--;
|
|
printf("\b \b");
|
|
}
|
|
} else if (input_char == '\r' || input_char == '\n') {
|
|
echo_and_reset(input_buffer, &buffer_index);
|
|
} else if (buffer_index < (MAX_INPUT_LEN - 1) && isprint(input_char)) {
|
|
printf("%c", input_char);
|
|
input_buffer[buffer_index] = input_char;
|
|
buffer_index++;
|
|
}
|
|
}
|
|
|
|
if (buffer_index > 0 && (time_us_64() - last_char_time) > TIMEOUT_US) {
|
|
printf("\n--- Timeout Reached (5.0s silence) ---\n");
|
|
echo_and_reset(input_buffer, &buffer_index);
|
|
last_char_time = time_us_64();
|
|
}
|
|
|
|
sleep_us(100);
|
|
}
|
|
|
|
printf("\nHost disconnected. Ending Echo Session.\n");
|
|
}
|
|
|
|
int main() {
|
|
stdio_init_all();
|
|
|
|
// Initialize I2C for the SSD1306 display (common pins: SDA=GPIO4, SCL=GPIO5)
|
|
i2c_init(i2c0, 400 * 1000);
|
|
gpio_set_function(4, GPIO_FUNC_I2C);
|
|
gpio_set_function(5, GPIO_FUNC_I2C);
|
|
gpio_pull_up(4);
|
|
gpio_pull_up(5);
|
|
|
|
// Create display object (address 0x3C is common). Adjust size/address if needed.
|
|
SSD1306 display(i2c0, 0x3C, Size::W128xH64);
|
|
display.clear();
|
|
display.sendBuffer();
|
|
for (int y = 0; y < 64; y++){
|
|
display.setPixel(64, y);
|
|
}
|
|
display.sendBuffer(); //Send buffer to device and show on screen
|
|
|
|
|
|
while (true) {
|
|
wait_for_usb_connection();
|
|
run_echo_session();
|
|
}
|
|
|
|
return 0;
|
|
}
|