我有这个代码示例,该示例用于制作20字节大小的数据包,这些数据包最终将通过BLE发送。我想更改代码,以便可以输入数据数组(加速度计读数)。
我的数据:
float ax, ay, az, gx, gy, gz, mx, my, mz, yaw, pitch, roll;
char myConcatenation[80];
sprintf(myConcatenation, "%3.2f,%3.2f,%3.2f,%3.2f,%3.2f,%3.2f,%3.2f,%3.2f,%3.2f,%3.2f,%3.2f,%3.2f", ax, ay, az, gx, gy, gz, mx, my, mz, yaw, pitch, roll);
函数定义:
std::vector<std::string> buildPackets(std::string data, size_t packetSize) {
// split up the packet
size_t partialPacketSize = packetSize - 4;
// calculate how many packets
size_t packetCount = data.length() / partialPacketSize;
packetCount = data.length() % partialPacketSize == 0 ? packetCount : packetCount + 1;
std::vector<std::string> packets;
// construct each packet
for (int i = 0; i < packetCount; i++) {
// start of packet
std::string packet = "##";
packet += (char)packetCount;
packet += (char)(i + 1);
std::string part = i == packetCount - 1 ? data.substr(i * partialPacketSize) : data.substr(i * partialPacketSize, partialPacketSize);
packet.append(part);
// add to vector of packets
packets.push_back(packet);
}
函数调用:
变量data
在这里是字符串,我所需要的只是放在我的myConcatenation[]
我应该对代码进行哪些更改才能使其正常工作?
std::string data = "averylongstringofdatathatislargerthantwentycharacters";
size_t chars = data.length();
size_t packetSize = 20;
// assume I have this characteristic already setup
if (chars > packetSize) {
auto packets = buildPackets(data, packetSize);
for (auto packet : packets) {
txCharacteristic->setValue(packet);
txCharacteristic->notify();
}
}
else {
txCharacteristic->setValue(data);
txCharacteristic->notify();
}
谢谢您的帮助。
编辑:
this is what I have now:
std::vector<std::string> buildPackets(std::string data, size_t packetSize) {
// split up the packet
size_t partialPacketSize = packetSize - 4;
// calculate how many packets
size_t packetCount = data.length() / partialPacketSize;
packetCount = data.length() % partialPacketSize == 0 ? packetCount : packetCount + 1;
std::vector<std::string> packets;
// construct each packet
for (int i = 0; i < packetCount; i++) {
// start of packet
std::string packet = "@";
packet += (char)packetCount;
packet += (char)(i + 1);
std::string part = i == packetCount - 1 ? data.substr(i * partialPacketSize) : data.substr(i * partialPacketSize, partialPacketSize);
packet.append(part);
// add to vector of packets
packets.push_back(packet);
}
return packets;
}
--------
**call function**
sprintf(myConcatenation, "#%3.2f,%3.2f,%3.2f,#%3.2f,%3.2f,%3.2f,#%3.2f,%3.2f,%3.2f,#%3.2f,%3.2f,%3.2f", ax, ay, az, gx, gy, gz, mx, my, mz, yaw, pitch, roll);
size_t packetSize = 20;
auto packets = buildPackets(myConcatenation, packetSize);
for (auto packet : packets) {
pCharacteristic->setValue(packet);
pCharacteristic->notify();
}
Serial.println(myConcatenation);
我可以问一下接收方吗?我的字符串在每个不同的传感器读数(#ax,ay,az,#gx,gy ...)的开头都有#
,在每个数据包的开头都有@
。您知道接收方应如何实现(我在MITAppInventor中做到了,但我想不出如何按顺序连接数据包并将它们附加到.csv文件中的想法。(每列=不同数据)。>
谢谢!
答案 0 :(得分:0)
String类提供了一个接受const char *输入的构造函数,因此您可以使用它来(隐式或显式)将名为data的变量转换为std :: string。
所以最后,只需将其传递给函数
float ax, ay, az, gx, gy, gz, mx, my, mz, yaw, pitch, roll;
char myConcatenation[80];
sprintf(myConcatenation, "%3.2f,%3.2f,%3.2f,%3.2f,%3.2f,%3.2f,%3.2f,%3.2f,%3.2f,%3.2f,%3.2f,%3.2f", ax, ay, az, gx, gy, gz, mx, my, mz, yaw, pitch, roll);
auto packets = buildPackets(myConcatenation, packetSize);
仅此而已。
一个快速的附加建议: