蓝牙低功耗慢反应时间
bluetooth low energy slow reaction time
我目前正在尝试使用 Adafruit Feather 32u4 通过 android 应用程序控制 2 个电机（小型遥控车）。这是我正在使用的：
用于应用程序的 MitAppInventor 2，显然是用于汽车的 Arduino IDE。
App Inventor 没有一种共享代码的愉快方式，但基本上我通过了配对，并到达了只需按下按钮的位置。它们完美地工作，使汽车向前和向后、向左和向右行驶。我遇到的问题是当我从电脑上拔下羽毛时，按下按钮和电机移动之间的时间大约为 1.5 秒，这绝对不适合驾驶。
Arduino 所做的就是从 phone 中获取数组，这将是 Status、0、1、2、3 或 4。根据该数字，它会以所需的方式打开电机方向。
我使用的代码只是修改了this指南
中的代码
这是我的 Arduino IDE 代码：
/*********************************************************************
This is an example for our nRF51822 based Bluefruit LE modules
Pick one up today in the adafruit shop!
Adafruit invests time and resources providing this open source code,
please support Adafruit and open-source hardware by purchasing
products from Adafruit!
MIT license, check LICENSE for more information
All text above, and the splash screen below must be included in
any redistribution
*********************************************************************/
#include <Arduino.h>
#include <SPI.h>
#if not defined (_VARIANT_ARDUINO_DUE_X_) && not defined (_VARIANT_ARDUINO_ZERO_)
#include <SoftwareSerial.h>
#endif
#include "Adafruit_BLE.h"
#include "Adafruit_BluefruitLE_SPI.h"
#include "Adafruit_BluefruitLE_UART.h"
#include "BluefruitConfig.h"
/*=========================================================================
APPLICATION SETTINGS
FACTORYRESET_ENABLE Perform a factory reset when running this sketch
Enabling this will put your Bluefruit LE module
in a 'known good' state and clear any config
data set in previous sketches or projects, so
running this at least once is a good idea.
When deploying your project, however, you will
want to disable factory reset by setting this
value to 0. If you are making changes to your
Bluefruit LE device via AT commands, and those
changes aren't persisting across resets, this
is the reason why. Factory reset will erase
the non-volatile memory where config data is
stored, setting it back to factory default
values.
Some sketches that require you to bond to a
central device (HID mouse, keyboard, etc.)
won't work at all with this feature enabled
since the factory reset will clear all of the
bonding data stored on the chip, meaning the
central device won't be able to reconnect.
MINIMUM_FIRMWARE_VERSION Minimum firmware version to have some new features
MODE_LED_BEHAVIOUR LED activity, valid options are
"DISABLE" or "MODE" or "BLEUART" or
"HWUART" or "SPI" or "MANUAL"
-----------------------------------------------------------------------*/
#define FACTORYRESET_ENABLE 1
#define MINIMUM_FIRMWARE_VERSION "0.6.6"
#define MODE_LED_BEHAVIOUR "MODE"
/*=========================================================================*/
// Pin Configuration and Firmware Declarations
#define LED_PIN 13
const unsigned long
BLINKTIME = 100;
unsigned long
t_blink = 0L;
int
blinkState = LOW;
// Create the bluefruit object, either software serial...uncomment these lines
/*
SoftwareSerial bluefruitSS = SoftwareSerial(BLUEFRUIT_SWUART_TXD_PIN, BLUEFRUIT_SWUART_RXD_PIN);
Adafruit_BluefruitLE_UART ble(bluefruitSS, BLUEFRUIT_UART_MODE_PIN,
BLUEFRUIT_UART_CTS_PIN, BLUEFRUIT_UART_RTS_PIN);
*/
/* ...or hardware serial, which does not need the RTS/CTS pins. Uncomment this line */
// Adafruit_BluefruitLE_UART ble(Serial1, BLUEFRUIT_UART_MODE_PIN);
/* ...hardware SPI, using SCK/MOSI/MISO hardware SPI pins and then user selected CS/IRQ/RST */
Adafruit_BluefruitLE_SPI ble(BLUEFRUIT_SPI_CS, BLUEFRUIT_SPI_IRQ, BLUEFRUIT_SPI_RST);
/* ...software SPI, using SCK/MOSI/MISO user-defined SPI pins and then user selected CS/IRQ/RST */
//Adafruit_BluefruitLE_SPI ble(BLUEFRUIT_SPI_SCK, BLUEFRUIT_SPI_MISO,
// BLUEFRUIT_SPI_MOSI, BLUEFRUIT_SPI_CS,
// BLUEFRUIT_SPI_IRQ, BLUEFRUIT_SPI_RST);
// A small helper
void error(const __FlashStringHelper*err) {
Serial.println(err);
while (1);
}
/**************************************************************************/
/*!
@brief Sets up the HW an the BLE module (this function is called
automatically on startup)
*/
/**************************************************************************/
void setup(void)
{
pinMode(LED_PIN, OUTPUT);
while (!Serial); // required for Flora & Micro
delay(500);
Serial.begin(115600);
Serial.println(F("Adafruit Bluefruit Command Mode Example"));
Serial.println(F("---------------------------------------"));
/* Initialise the module */
Serial.print(F("Initialising the Bluefruit LE module: "));
if ( !ble.begin() )
{
error(F("Couldn't find Bluefruit, make sure it's in CoMmanD mode & check wiring?"));
}
Serial.println( F("OK!") );
if ( FACTORYRESET_ENABLE )
{
/* Perform a factory reset to make sure everything is in a known state */
Serial.println(F("Performing a factory reset: "));
if ( ! ble.factoryReset() ){
error(F("Couldn't factory reset"));
}
}
/* Disable command echo from Bluefruit */
ble.echo(false);
Serial.println("Requesting Bluefruit info:");
/* Print Bluefruit information */
ble.info();
Serial.println(F("Please use Adafruit Bluefruit LE app to connect in UART mode"));
Serial.println(F("Then Enter characters to send to Bluefruit"));
Serial.println();
ble.verbose(false); // debug info is a little annoying after this point!
/* Wait for connection */
while (! ble.isConnected()) {
delay(500);
}
// LED Activity command is only supported from 0.6.6
if ( ble.isVersionAtLeast(MINIMUM_FIRMWARE_VERSION) )
{
// Change Mode LED Activity
Serial.println(F("******************************"));
Serial.println(F("Change LED activity to " MODE_LED_BEHAVIOUR));
ble.sendCommandCheckOK("AT+HWModeLED=" MODE_LED_BEHAVIOUR);
Serial.println(F("******************************"));
}
}
/**************************************************************************/
/*!
@brief Constantly poll for new command or response data
*/
/**************************************************************************/
void loop(void)
{
// Now Check for incoming characters from Bluefruit
ble.println("AT+BLEUARTRX");
ble.readline();
ble.waitForOK();
String BLEbuffer = ble.buffer;
if (BLEbuffer.length() && BLEbuffer.indexOf("OK") == -1)
Serial.print(F("[Recv] ")); Serial.println(BLEbuffer);
if (BLEbuffer.indexOf("Status") >= 0) {
Serial.println(F("Status Request Received"));
ble.print("AT+BLEUARTTX=");
if (t_blink) {
ble.println("BLNK");
}
else {
if (blinkState)
ble.println("ON");
else
ble.println("OFF");
}
// check response stastus
if (! ble.waitForOK() ) {
Serial.println(F("Failed to get response"));
}
ble.println("AT+BLEUARTRX");
}
else if (BLEbuffer.indexOf("0") >= 0) {
blinkState = LOW;
digitalWrite(LED_PIN, blinkState);
analogWrite(13, 0);
analogWrite(11, 0);
digitalWrite(18, LOW);
digitalWrite(19, LOW);
digitalWrite(20, LOW);
digitalWrite(21, LOW);
t_blink = 0;
ble.print("AT+BLEUARTTX=");
ble.println("OFF");
//Serial.println(F("OFF Request Received"));
ble.println("AT+BLEUARTRX");
}
else if (BLEbuffer.indexOf("1") >= 0) {
//if (!t_blink) t_blink = millis();
analogWrite(13, 100);
analogWrite(11, 100);
digitalWrite(18, HIGH);
digitalWrite(19, LOW);
digitalWrite(20, LOW);
digitalWrite(21, HIGH);
ble.print("AT+BLEUARTTX=");
ble.println("FORWARD");
//Serial.println(F("BLINK Request Received"));
ble.println("AT+BLEUARTRX");
}
else if (BLEbuffer.indexOf("2") >= 0) {
blinkState = HIGH;
digitalWrite(LED_PIN, blinkState);
analogWrite(13, 100);
analogWrite(11, 100);
digitalWrite(18, LOW);
digitalWrite(19, HIGH);
digitalWrite(20, HIGH);
digitalWrite(21, LOW);
t_blink = 0;
ble.print("AT+BLEUARTTX=");
ble.println("BACK");
//Serial.println(F("ON Request Received"));
ble.println("AT+BLEUARTRX");
}
else if (BLEbuffer.indexOf("3") >= 0) {
analogWrite(13, 100);
analogWrite(11, 100);
digitalWrite(18, HIGH);
digitalWrite(19, LOW);
digitalWrite(20, HIGH);
digitalWrite(21, LOW);
ble.print("AT+BLEUARTTX=");
ble.println("LEFT");
//Serial.println(F("BLINK Request Received"));
ble.println("AT+BLEUARTRX");
}
else if (BLEbuffer.indexOf("4") >= 0) {
//if (!t_blink) t_blink = millis();
analogWrite(13, 100);
analogWrite(11, 100);
digitalWrite(18, LOW);
digitalWrite(19, HIGH);
digitalWrite(20, LOW);
digitalWrite(21, HIGH);
ble.print("AT+BLEUARTTX=");
ble.println("RIGHT");
//Serial.println(F("BLINK Request Received"));
ble.println("AT+BLEUARTRX");
}
BLEbuffer = "";
}
所有这一切都应该在每个循环中读取一行，挑选出字符，然后 运行 该字符的代码块。我没有看到它滞后的原因，因为数据量似乎非常少。如果我插入它和串行监视器 运行，也几乎没有延迟。我一拔掉它，它就保持连接状态，除了巨大的延迟外，一切仍然有效。
我最初的想法是缓冲区中的 "blank" 命令太满了，它必须在真正的命令之前处理所有这些命令，但如果是这样的话，它会滞后于串行监视器打开。
到目前为止，我已经尝试将波特率更改为较低的数字，认为 300 是最小值，如果问题是堆栈收到太多命令来排序，则与 115600 相比，300 将是一个很小的数量我之前有过，但这没有产生任何结果。我也尝试过削减代码，这似乎是我可以用来让它仍然有效的最少代码。
我读到应用 onSerialEvent() 方法可能会有所帮助，但是当我尝试时它卡在了：
if ( ble.isVersionAtLeast(MINIMUM_FIRMWARE_VERSION) )
{
// Change Mode LED Activity
Serial.println(F("******************************"));
Serial.println(F("Change LED activity to " MODE_LED_BEHAVIOUR));
ble.sendCommandCheckOK("AT+HWModeLED=" MODE_LED_BEHAVIOUR);
Serial.println(F("******************************"));
}
莫非是接线问题？例如，我可能需要在电机前加一个电容器，以防止它们必须 "ramp up" 达到实际启动所需的功率？我对电气方面的知识不是很了解，但这只是一个想法。
所以解决方案非常简单，我不认为它只是一个 BLE 解决方案，因为它只与串行命令有关（即 serial.print()）。在设备不再连接到计算机后在代码中包含这些命令将导致电路板不响应它们或花费额外的时间尝试处理它们，然后最终放弃（我对实际发生的事情的猜测）。
解决方案是在上传到设备之前简单地注释掉所有串行命令，目的是 运行 不插入代码。或者您显然可以将它们全部删除，但这可能会妨碍您下次尝试编辑代码时的调试体验。
我想与其删除这个问题，不如用我发现的内容来回答它可能会在将来帮助其他人。
我目前正在尝试使用 Adafruit Feather 32u4 通过 android 应用程序控制 2 个电机（小型遥控车）。这是我正在使用的：
用于应用程序的 MitAppInventor 2，显然是用于汽车的 Arduino IDE。
App Inventor 没有一种共享代码的愉快方式，但基本上我通过了配对，并到达了只需按下按钮的位置。它们完美地工作，使汽车向前和向后、向左和向右行驶。我遇到的问题是当我从电脑上拔下羽毛时，按下按钮和电机移动之间的时间大约为 1.5 秒，这绝对不适合驾驶。
Arduino 所做的就是从 phone 中获取数组，这将是 Status、0、1、2、3 或 4。根据该数字，它会以所需的方式打开电机方向。
我使用的代码只是修改了this指南
中的代码这是我的 Arduino IDE 代码：
/*********************************************************************
This is an example for our nRF51822 based Bluefruit LE modules
Pick one up today in the adafruit shop!
Adafruit invests time and resources providing this open source code,
please support Adafruit and open-source hardware by purchasing
products from Adafruit!
MIT license, check LICENSE for more information
All text above, and the splash screen below must be included in
any redistribution
*********************************************************************/
#include <Arduino.h>
#include <SPI.h>
#if not defined (_VARIANT_ARDUINO_DUE_X_) && not defined (_VARIANT_ARDUINO_ZERO_)
#include <SoftwareSerial.h>
#endif
#include "Adafruit_BLE.h"
#include "Adafruit_BluefruitLE_SPI.h"
#include "Adafruit_BluefruitLE_UART.h"
#include "BluefruitConfig.h"
/*=========================================================================
APPLICATION SETTINGS
FACTORYRESET_ENABLE Perform a factory reset when running this sketch
Enabling this will put your Bluefruit LE module
in a 'known good' state and clear any config
data set in previous sketches or projects, so
running this at least once is a good idea.
When deploying your project, however, you will
want to disable factory reset by setting this
value to 0. If you are making changes to your
Bluefruit LE device via AT commands, and those
changes aren't persisting across resets, this
is the reason why. Factory reset will erase
the non-volatile memory where config data is
stored, setting it back to factory default
values.
Some sketches that require you to bond to a
central device (HID mouse, keyboard, etc.)
won't work at all with this feature enabled
since the factory reset will clear all of the
bonding data stored on the chip, meaning the
central device won't be able to reconnect.
MINIMUM_FIRMWARE_VERSION Minimum firmware version to have some new features
MODE_LED_BEHAVIOUR LED activity, valid options are
"DISABLE" or "MODE" or "BLEUART" or
"HWUART" or "SPI" or "MANUAL"
-----------------------------------------------------------------------*/
#define FACTORYRESET_ENABLE 1
#define MINIMUM_FIRMWARE_VERSION "0.6.6"
#define MODE_LED_BEHAVIOUR "MODE"
/*=========================================================================*/
// Pin Configuration and Firmware Declarations
#define LED_PIN 13
const unsigned long
BLINKTIME = 100;
unsigned long
t_blink = 0L;
int
blinkState = LOW;
// Create the bluefruit object, either software serial...uncomment these lines
/*
SoftwareSerial bluefruitSS = SoftwareSerial(BLUEFRUIT_SWUART_TXD_PIN, BLUEFRUIT_SWUART_RXD_PIN);
Adafruit_BluefruitLE_UART ble(bluefruitSS, BLUEFRUIT_UART_MODE_PIN,
BLUEFRUIT_UART_CTS_PIN, BLUEFRUIT_UART_RTS_PIN);
*/
/* ...or hardware serial, which does not need the RTS/CTS pins. Uncomment this line */
// Adafruit_BluefruitLE_UART ble(Serial1, BLUEFRUIT_UART_MODE_PIN);
/* ...hardware SPI, using SCK/MOSI/MISO hardware SPI pins and then user selected CS/IRQ/RST */
Adafruit_BluefruitLE_SPI ble(BLUEFRUIT_SPI_CS, BLUEFRUIT_SPI_IRQ, BLUEFRUIT_SPI_RST);
/* ...software SPI, using SCK/MOSI/MISO user-defined SPI pins and then user selected CS/IRQ/RST */
//Adafruit_BluefruitLE_SPI ble(BLUEFRUIT_SPI_SCK, BLUEFRUIT_SPI_MISO,
// BLUEFRUIT_SPI_MOSI, BLUEFRUIT_SPI_CS,
// BLUEFRUIT_SPI_IRQ, BLUEFRUIT_SPI_RST);
// A small helper
void error(const __FlashStringHelper*err) {
Serial.println(err);
while (1);
}
/**************************************************************************/
/*!
@brief Sets up the HW an the BLE module (this function is called
automatically on startup)
*/
/**************************************************************************/
void setup(void)
{
pinMode(LED_PIN, OUTPUT);
while (!Serial); // required for Flora & Micro
delay(500);
Serial.begin(115600);
Serial.println(F("Adafruit Bluefruit Command Mode Example"));
Serial.println(F("---------------------------------------"));
/* Initialise the module */
Serial.print(F("Initialising the Bluefruit LE module: "));
if ( !ble.begin() )
{
error(F("Couldn't find Bluefruit, make sure it's in CoMmanD mode & check wiring?"));
}
Serial.println( F("OK!") );
if ( FACTORYRESET_ENABLE )
{
/* Perform a factory reset to make sure everything is in a known state */
Serial.println(F("Performing a factory reset: "));
if ( ! ble.factoryReset() ){
error(F("Couldn't factory reset"));
}
}
/* Disable command echo from Bluefruit */
ble.echo(false);
Serial.println("Requesting Bluefruit info:");
/* Print Bluefruit information */
ble.info();
Serial.println(F("Please use Adafruit Bluefruit LE app to connect in UART mode"));
Serial.println(F("Then Enter characters to send to Bluefruit"));
Serial.println();
ble.verbose(false); // debug info is a little annoying after this point!
/* Wait for connection */
while (! ble.isConnected()) {
delay(500);
}
// LED Activity command is only supported from 0.6.6
if ( ble.isVersionAtLeast(MINIMUM_FIRMWARE_VERSION) )
{
// Change Mode LED Activity
Serial.println(F("******************************"));
Serial.println(F("Change LED activity to " MODE_LED_BEHAVIOUR));
ble.sendCommandCheckOK("AT+HWModeLED=" MODE_LED_BEHAVIOUR);
Serial.println(F("******************************"));
}
}
/**************************************************************************/
/*!
@brief Constantly poll for new command or response data
*/
/**************************************************************************/
void loop(void)
{
// Now Check for incoming characters from Bluefruit
ble.println("AT+BLEUARTRX");
ble.readline();
ble.waitForOK();
String BLEbuffer = ble.buffer;
if (BLEbuffer.length() && BLEbuffer.indexOf("OK") == -1)
Serial.print(F("[Recv] ")); Serial.println(BLEbuffer);
if (BLEbuffer.indexOf("Status") >= 0) {
Serial.println(F("Status Request Received"));
ble.print("AT+BLEUARTTX=");
if (t_blink) {
ble.println("BLNK");
}
else {
if (blinkState)
ble.println("ON");
else
ble.println("OFF");
}
// check response stastus
if (! ble.waitForOK() ) {
Serial.println(F("Failed to get response"));
}
ble.println("AT+BLEUARTRX");
}
else if (BLEbuffer.indexOf("0") >= 0) {
blinkState = LOW;
digitalWrite(LED_PIN, blinkState);
analogWrite(13, 0);
analogWrite(11, 0);
digitalWrite(18, LOW);
digitalWrite(19, LOW);
digitalWrite(20, LOW);
digitalWrite(21, LOW);
t_blink = 0;
ble.print("AT+BLEUARTTX=");
ble.println("OFF");
//Serial.println(F("OFF Request Received"));
ble.println("AT+BLEUARTRX");
}
else if (BLEbuffer.indexOf("1") >= 0) {
//if (!t_blink) t_blink = millis();
analogWrite(13, 100);
analogWrite(11, 100);
digitalWrite(18, HIGH);
digitalWrite(19, LOW);
digitalWrite(20, LOW);
digitalWrite(21, HIGH);
ble.print("AT+BLEUARTTX=");
ble.println("FORWARD");
//Serial.println(F("BLINK Request Received"));
ble.println("AT+BLEUARTRX");
}
else if (BLEbuffer.indexOf("2") >= 0) {
blinkState = HIGH;
digitalWrite(LED_PIN, blinkState);
analogWrite(13, 100);
analogWrite(11, 100);
digitalWrite(18, LOW);
digitalWrite(19, HIGH);
digitalWrite(20, HIGH);
digitalWrite(21, LOW);
t_blink = 0;
ble.print("AT+BLEUARTTX=");
ble.println("BACK");
//Serial.println(F("ON Request Received"));
ble.println("AT+BLEUARTRX");
}
else if (BLEbuffer.indexOf("3") >= 0) {
analogWrite(13, 100);
analogWrite(11, 100);
digitalWrite(18, HIGH);
digitalWrite(19, LOW);
digitalWrite(20, HIGH);
digitalWrite(21, LOW);
ble.print("AT+BLEUARTTX=");
ble.println("LEFT");
//Serial.println(F("BLINK Request Received"));
ble.println("AT+BLEUARTRX");
}
else if (BLEbuffer.indexOf("4") >= 0) {
//if (!t_blink) t_blink = millis();
analogWrite(13, 100);
analogWrite(11, 100);
digitalWrite(18, LOW);
digitalWrite(19, HIGH);
digitalWrite(20, LOW);
digitalWrite(21, HIGH);
ble.print("AT+BLEUARTTX=");
ble.println("RIGHT");
//Serial.println(F("BLINK Request Received"));
ble.println("AT+BLEUARTRX");
}
BLEbuffer = "";
}
所有这一切都应该在每个循环中读取一行，挑选出字符，然后 运行 该字符的代码块。我没有看到它滞后的原因，因为数据量似乎非常少。如果我插入它和串行监视器 运行，也几乎没有延迟。我一拔掉它，它就保持连接状态，除了巨大的延迟外，一切仍然有效。
我最初的想法是缓冲区中的 "blank" 命令太满了，它必须在真正的命令之前处理所有这些命令，但如果是这样的话，它会滞后于串行监视器打开。
到目前为止，我已经尝试将波特率更改为较低的数字，认为 300 是最小值，如果问题是堆栈收到太多命令来排序，则与 115600 相比，300 将是一个很小的数量我之前有过，但这没有产生任何结果。我也尝试过削减代码，这似乎是我可以用来让它仍然有效的最少代码。
我读到应用 onSerialEvent() 方法可能会有所帮助，但是当我尝试时它卡在了：
if ( ble.isVersionAtLeast(MINIMUM_FIRMWARE_VERSION) )
{
// Change Mode LED Activity
Serial.println(F("******************************"));
Serial.println(F("Change LED activity to " MODE_LED_BEHAVIOUR));
ble.sendCommandCheckOK("AT+HWModeLED=" MODE_LED_BEHAVIOUR);
Serial.println(F("******************************"));
}
莫非是接线问题？例如，我可能需要在电机前加一个电容器，以防止它们必须 "ramp up" 达到实际启动所需的功率？我对电气方面的知识不是很了解，但这只是一个想法。
所以解决方案非常简单，我不认为它只是一个 BLE 解决方案，因为它只与串行命令有关（即 serial.print()）。在设备不再连接到计算机后在代码中包含这些命令将导致电路板不响应它们或花费额外的时间尝试处理它们，然后最终放弃（我对实际发生的事情的猜测）。
解决方案是在上传到设备之前简单地注释掉所有串行命令，目的是 运行 不插入代码。或者您显然可以将它们全部删除，但这可能会妨碍您下次尝试编辑代码时的调试体验。
我想与其删除这个问题，不如用我发现的内容来回答它可能会在将来帮助其他人。