File content as of revision 5:e35b1b281466:

#include <mbed.h>
#include "main.h"

PwmOut pwmA(PB_11); /* CN10-18 */
PwmOut pwmB(PA_15); /* CN7-17 */
PwmOut pwmC(PB_1); /* CN10-24 */
PwmOut pwmD(PC_6); /* CN10-4 */

RawSerial pc(USBTX, USBRX);
char pcbuf[128];
int pcbuf_len;

bool initialized = false;

/* return true for parsed  */
bool parse_radio_rx(uint8_t* rx_buf)
{
    PwmOut* pwmPtr;

    switch (rx_buf[0]) {
        case CMD_PWM_A: pwmPtr = &pwmA; break;
        case CMD_PWM_B: pwmPtr = &pwmB; break;
        case CMD_PWM_C: pwmPtr = &pwmC; break;
        case CMD_PWM_D: pwmPtr = &pwmD; break;
        default: return false;
    }

    pwmPtr->period(1.0 / rx_buf[1]);    // rx_buf[1] is Hz
    pwmPtr->write(rx_buf[2] / 255.0);
    printf("%uHz, duty:%.2f\r\n", rx_buf[1], rx_buf[2]/255.0);
    return true;
}

void cmd_pwm(uint8_t idx)
{
    uint8_t buf[4];
    unsigned ch, p, d;
 
    if (sscanf(pcbuf+idx, "%u %u %u", &ch, &p, &d) != 3) {
        printf("parse fail\r\n");
        return;
    }

    switch (ch) {
        case 0: buf[0] = CMD_PWM_A; break;
        case 1: buf[0] = CMD_PWM_B; break;
        case 2: buf[0] = CMD_PWM_C; break;
        case 3: buf[0] = CMD_PWM_D; break;
    }
    buf[1] = p;
    buf[2] = d;
    radio_tx(buf, 3);
}

void cmd_help(uint8_t args_at);

typedef struct {
    const char* const cmd;
    void (*handler)(uint8_t args_at);
    const char* const arg_descr;
    const char* const description;
} menu_item_t;

const menu_item_t menu_items[] = 
{   /* after first character, command names must be [A-Za-z] */
    { "?", cmd_help, "","show available commands"},
    { "p", cmd_pwm, "%u %u", "set pwm period, duty"},
    { NULL, NULL, NULL, NULL }
};

void cmd_help(uint8_t args_at)
{
    int i;
    for (i = 0; menu_items[i].cmd != NULL ; i++) {
        printf("%s%s\t%s\r\n", menu_items[i].cmd, menu_items[i].arg_descr, menu_items[i].description);
    }
}

void rx_callback()
{
    static uint8_t pcbuf_idx = 0;
    static uint8_t prev_len = 0;;
    char c = pc.getc();
 
    if (c == 8) {
        if (pcbuf_idx > 0) {
            pc.putc(8);
            pc.putc(' ');
            pc.putc(8);
            pcbuf_idx--;
        }
    } else if (c == 3) {    // ctrl-C
        pcbuf_len = -1;
    } else if (c == '\r') {
        if (pcbuf_idx == 0) {
            pcbuf_len = prev_len;
        } else {
            pcbuf[pcbuf_idx] = 0;   // null terminate
            prev_len = pcbuf_idx;
            pcbuf_idx = 0;
            pcbuf_len = prev_len;
        }
    } else if (pcbuf_idx < sizeof(pcbuf)) {
        pcbuf[pcbuf_idx++] = c;
        pc.putc(c);
    }
}

void uart_service()
{
    int i;
    uint8_t user_cmd_len;

    if (!initialized) {
        pc.attach(&rx_callback);
        initialized = true;
    }

    if (pcbuf_len < 0) {    // ctrl-C
        return;
    }
    if (pcbuf_len == 0)
        return;
        
    printf("\r\n");
        
    /* get end of user-entered command */
    user_cmd_len = 1;   // first character can be any character
    for (i = 1; i <= pcbuf_len; i++) {
        if (pcbuf[i] < 'A' || (pcbuf[i] > 'Z' && pcbuf[i] < 'a') || pcbuf[i] > 'z') {
            user_cmd_len = i;
            break;
        }
    }
 
    for (i = 0; menu_items[i].cmd != NULL ; i++) {
        int mi_len = strlen(menu_items[i].cmd);
 
        if (menu_items[i].handler && user_cmd_len == mi_len && (strncmp(pcbuf, menu_items[i].cmd, mi_len) == 0)) {
            while (pcbuf[mi_len] == ' ')   // skip past spaces
                mi_len++;
            menu_items[i].handler(mi_len);
            break;
        }
    }
 
    pcbuf_len = 0;
    printf("> ");
    fflush(stdout); 
}