hello
putting together this sketch and this comes up,
GettingStarted:133: error: cannot convert 'float' to 'const char*' for argument '1' to 'int printf(const char*, ...)'
how do I convert float to const char?
/*
Copyright (C) 2011 J. Coliz <maniacbug@ymail.com>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
version 2 as published by the Free Software Foundation.
*/
/**
* Example for Getting Started with nRF24L01+ radios.
*
* This is an example of how to use the RF24 class. Write this sketch to two
* different nodes. Put one of the nodes into 'transmit' mode by connecting
* with the serial monitor and sending a 'T'. The ping node sends the current
* time to the pong node, which responds by sending the value back. The ping
* node can then see how long the whole cycle took.
*/
#include <SPI.h>
#include "nRF24L01.h"
#include "RF24.h"
#include "printf.h"
#include <Wire.h>
#include <Adafruit_BMP085.h>
//
// Hardware configuration
//
// Set up nRF24L01 radio on SPI bus plus pins 9 & 10
RF24 radio(9,10);
Adafruit_BMP085 bmp;
//
// Topology
//
// Radio pipe addresses for the 2 nodes to communicate.
const uint64_t pipes[2] = { 0xF0F0F0F0E1LL, 0xF0F0F0F0D2LL };
//
// Role management
//
// Set up role. This sketch uses the same software for all the nodes
// in this system. Doing so greatly simplifies testing.
//
// The various roles supported by this sketch
typedef enum { role_ping_out = 1, role_pong_back } role_e;
// The debug-friendly names of those roles
const char* role_friendly_name[] = { "invalid", "Ping out", "Pong back"};
// The role of the current running sketch
role_e role = role_pong_back;
void setup(void)
{
//
// Print preamble
//
bmp.begin();
Serial.begin(57600);
printf_begin();
printf("\n\rRF24/examples/GettingStarted/\n\r");
printf("ROLE: %s\n\r",role_friendly_name[role]);
printf("*** PRESS 'T' to begin transmitting to the other node\n\r");
//
// Setup and configure rf radio
//
radio.begin();
// optionally, increase the delay between retries & # of retries
radio.setRetries(15,15);
// optionally, reduce the payload size. seems to
// improve reliability
//radio.setPayloadSize(8);
//
// Open pipes to other nodes for communication
//
// This simple sketch opens two pipes for these two nodes to communicate
// back and forth.
// Open 'our' pipe for writing
// Open the 'other' pipe for reading, in position #1 (we can have up to 5 pipes open for reading)
//if ( role == role_ping_out )
{
//radio.openWritingPipe(pipes[0]);
radio.openReadingPipe(1,pipes[1]);
}
//else
{
//radio.openWritingPipe(pipes[1]);
//radio.openReadingPipe(1,pipes[0]);
}
//
// Start listening
//
radio.startListening();
//
// Dump the configuration of the rf unit for debugging
//
radio.printDetails();
}
void loop(void)
{
//
// Ping out role. Repeatedly send the current time
//
if (role == role_ping_out)
{
// First, stop listening so we can talk.
radio.stopListening();
// Take the time, and send it. This will block until complete
unsigned long time = millis();
printf("Now sending %lu...",time);
bool ok = radio.write( &time, sizeof(unsigned long) );
printf("Temperature = "); //this bit
printf(bmp.readTemperature());
printf(" *C");
if (ok)
printf("ok...");
else
printf("failed.\n\r");
// Now, continue listening
radio.startListening();
// Wait here until we get a response, or timeout (250ms)
unsigned long started_waiting_at = millis();
bool timeout = false;
while ( ! radio.available() && ! timeout )
if (millis() - started_waiting_at > 200 )
timeout = true;
// Describe the results
if ( timeout )
{
printf("Failed, response timed out.\n\r");
}
else
{
// Grab the response, compare, and send to debugging spew
unsigned long got_time;
radio.read( &got_time, sizeof(unsigned long) );
// Spew it
printf("Got response %lu, round-trip delay: %lu\n\r",got_time,millis()-got_time);
}
// Try again 1s later
delay(1000);
}
//
// Pong back role. Receive each packet, dump it out, and send it back
//
if ( role == role_pong_back )
{
// if there is data ready
if ( radio.available() )
{
// Dump the payloads until we've gotten everything
unsigned long got_time;
bool done = false;
while (!done)
{
// Fetch the payload, and see if this was the last one.
done = radio.read( &got_time, sizeof(unsigned long) );
// Spew it
printf("Got payload %lu...",got_time);
// Delay just a little bit to let the other unit
// make the transition to receiver
delay(20);
}
// First, stop listening so we can talk
radio.stopListening();
// Send the final one back.
radio.write( &got_time, sizeof(unsigned long) );
printf("Sent response.\n\r");
// Now, resume listening so we catch the next packets.
radio.startListening();
}
}
//
// Change roles
//
if ( Serial.available() )
{
char c = toupper(Serial.read());
if ( c == 'T' && role == role_pong_back )
{
printf("*** CHANGING TO TRANSMIT ROLE -- PRESS 'R' TO SWITCH BACK\n\r");
// Become the primary transmitter (ping out)
role = role_ping_out;
radio.openWritingPipe(pipes[0]);
radio.openReadingPipe(1,pipes[1]);
}
else if ( c == 'R' && role == role_ping_out )
{
printf("*** CHANGING TO RECEIVE ROLE -- PRESS 'T' TO SWITCH BACK\n\r");
// Become the primary receiver (pong back)
role = role_pong_back;
radio.openWritingPipe(pipes[1]);
radio.openReadingPipe(1,pipes[0]);
}
}
}
// vim:cin:ai:sts=2 sw=2 ft=cpp