Arduino Float Value to Python using NRF24L01

本文关键字：using NRF24L01 Python to Float Value Arduino 更新时间：2023-10-16

我试图通过NRF24L01将温度传感器数据发送到Raspberry Pi，并使用python在Raspberry Pi中读取它。但是温度传感器数据以字母的形式来到树莓派，我发现这是 Ascii 值。我不确定如何显示从Arduino到Raspberry Pi的实际读数

这是Arduino代码：


#include <DallasTemperature.h>
#include <OneWire.h>
#include <SPI.h>
#include <RF24.h>
#include "printf.h"
#define ONE_WIRE_BUS 2
OneWire oneWire (ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);
RF24 radio(9, 10);
void setup(void) {
Serial.begin(9600);
sensors.begin();
radio.begin() ;
radio.setPALevel(RF24_PA_MAX) ;
radio.setChannel(0x76) ;
radio.openWritingPipe(0xF0F0F0F0E1LL) ;
radio.enableDynamicPayloads() ;
radio.powerUp() ;
}
void loop(void) {
sensors.requestTemperatures();
float temperature = sensors.getTempFByIndex(0);
radio.write(&temperature, sizeof(float));
delay(1000);
Serial.print(sensors.getTempFByIndex(0));
}

这是 Python 中 Raspberry Pi 的代码

from lib_nrf24 import NRF24
import time
import spidev
GPIO.setmode(GPIO.BCM)
GPIO.setwarnings(False)
pipes = [[0xE8, 0xE8, 0xF0, 0xF0, 0xE1], [0xF0, 0xF0, 0xF0, 0xF0, 0xE1]]
radio = NRF24(GPIO, spidev.SpiDev())
radio.begin(0, 17)
radio.setPayloadSize(32)
radio.setChannel(0x76)
radio.setDataRate(NRF24.BR_1MBPS)
radio.setPALevel(NRF24.PA_MIN)
radio.setAutoAck(True)
radio.enableDynamicPayloads()
radio.enableAckPayload()
radio.openReadingPipe(1, pipes[1])
radio.printDetails()
radio.startListening()
while True:
while not radio.available(0):
time.sleep(1/100)
receivedMessage = []
radio.read(receivedMessage, radio.getDynamicPayloadSize())
print("Received: {}".format(receivedMessage))
print("Translating...")
string = ""
for n in receivedMessage:
if (n >= 32 and n <= 126):
string += chr(n)
print("Our received message decodes to: {}".format(string))

我想以数字而不是字母的形式获取温度值。而不是这样：

正在翻译。。。我们收到的消息解码为：N

您应该收到 4 个字节(在大多数体系结构上，sizeof(float)始终为 4)，因此请检查您收到的数据：

if (len(receivedMessage) == 4)

四个字节表示一个浮点数，以便对其进行转换：

temperature = float.fromhex(''.join(format(x, '02x') for x in receivedMessage))

四个字节被转换为十六进制字符串并转换为浮点数。

编辑(未测试)：

receivedMessage = []
radio.read(receivedMessage, radio.getDynamicPayloadSize())
if (len(receivedMessage) == 4)
temperature = float.fromhex(''.join(format(x, '02x') for x in receivedMessage))
print '%.2f' % temperature