I report a strange behaviour on deepsleep mangemnt: I have an esp8266 NodeMCU AMICA V2 board, if i put in deepsleep for 1800 seconds its fine and wake up as expected, then if I put in deepsleep for 3600 seconds it wont wakeup, i dont understand why since the code is still the same. To put on deepsleep i use this function:
(in setup i also have added "pinMode(D0, WAKEUP_PULLUP);" but nothing is changed):
sleepSeconds = 3600;
Serial.println(sleepSeconds);
digitalWrite(power, LOW);
delay(250);
ESP.deepSleep (sleepSeconds * 1000000);
delay(2000);
I also tested the max deepsleep time with below function and resulting on 13591117817us, that is almost 226 minutes so it should not a problem:
String result = "";
uint8_t base = 10;
do {
char c = input % base;
input /= base;
if (c < 10)
c +='0';
else
c += 'A' - 10;
result = c + result;
} while (input);
return result;
}
Related
To simplify a function with many terms, a program would be useful that searches for patterns in a file and arranges them in a ranking list. I can imagine that this is an elaborate process, but I'm sure there are people who have built something like this.
An example of a text:
sin(t1)*cos(t1)*t1+t1-sin(t1)*sin(t1-pi)
This should give me such an output like this (min. 2 letters):
6x: "t1"
4x: "(t1"
3x: "n(t1"
3x: "sin"
3x: "sin("
2x: "sin(t1)"
etc.
Does this problem have a name (which I don't know)? Is there a known algorithm that could solve the problem for me?
I have written a small program with QT, which fulfills the task. The approach is to try everything. To solve my problem, it will probably take a few days, because the text files are very large.
If I have the following text as input ("text.txt"):
sin(t1)*cos(t1)*t1+t1-sin(t1)*sin(t1-pi)
I have with the parameters: length 2-5, minimum occurrence: 3
following result:
t1 6
(t 4
(t1 4
si 3
in 3
n( 3
1) 3
)* 3
sin 3
in( 3
n(t 3
t1) 3
1)* 3
sin( 3
in(t 3
n(t1 3
(t1) 3
t1)* 3
sin(t 3
in(t1 3
(t1)* 3
Code:
#include <QCoreApplication>
#include <qdebug.h>
#include <qstring.h>
#include <qfile.h>
#include <qtextstream.h>
int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
QString * wholefile = new QString;
uint64_t minchar = 2;
uint64_t maxchar = 5;
uint64_t min_occur = 3;
QFile file("text.txt");
if(!file.open(QIODevice::ReadOnly)) {
qDebug()<<"error reading file";
}
QTextStream in(&file);
while(!in.atEnd()) {
QString line = in.readLine();
wholefile->append(line);
}
file.close();
QStringList * allpatterns = new QStringList;
for(uint64_t i=minchar; i<=maxchar;i++){
for(uint64_t pos=0; pos<wholefile->length()-i;pos++){
QString pattern = wholefile->mid(pos,i);
if(allpatterns->contains(pattern)==0){
allpatterns->append(pattern);
}
}
}
uint64_t * strcnt = new uint64_t[allpatterns->length()];
uint64_t maximum_cnt = 0;
QStringList * interestingpatterns = new QStringList;
uint64_t nr_of_patterns = 0;
for(uint64_t i=0; i<allpatterns->length();i++){
QString str = allpatterns->at(i);
strcnt[nr_of_patterns] = wholefile->count(str);
if(strcnt[nr_of_patterns]>=min_occur){
if(strcnt[nr_of_patterns]>maximum_cnt){
maximum_cnt = strcnt[nr_of_patterns];
}
interestingpatterns->append(str);
nr_of_patterns++;
}
}
/* display result*/
QFile file2("out.txt");
if (!file2.open(QIODevice::WriteOnly | QIODevice::Text))
qDebug()<<"error writing file";
QTextStream out(&file2);
uint64_t current_max = maximum_cnt;
while(current_max>=min_occur){
for(uint64_t i=0; i<interestingpatterns->length();i++){
if(strcnt[i]==current_max){
QString str = interestingpatterns->at(i);
qDebug()<<str<<strcnt[i];
out <<str<<" "<< QString::number(strcnt[i])<<"\n";
}
}
current_max--;
}
file2.close();
return a.exec();
}
I'm currently implementing symbol time recovery blocks. The idea is to be able to choose different TEDs (Gardner, Zero-crossing, Early-Late, Maximum-likelihood etc). In blocks like M&M recovery, the gain parameters of the loop are expressed explicitly (gain_omega and gain_mu) which can be difficult to get right. The contro_loop class is, however, more convenient (loop characteristics can be specified by "loop bandwidth" and "damping factor"(zeta)). So my first test started with the re-implementation of the MM Clock Recovery with a control loop. The work function of this block is shown below (Comments are mine)
clock_recovery_mm_ff_impl::general_work(int noutput_items,
gr_vector_int &ninput_items,
gr_vector_const_void_star &input_items,
gr_vector_void_star &output_items)
{
const float *in = (const float *)input_items[0];
float *out = (float *)output_items[0];
int ii = 0; // input index
int oo = 0; // output index
int ni = ninput_items[0] - d_interp->ntaps(); // don't use more input than this
float mm_val;
while(oo < noutput_items && ii < ni ) {
// produce output sample
out[oo] = d_interp->interpolate(&in[ii], d_mu); //Interpolation
mm_val = slice(d_last_sample) * out[oo] - slice(out[oo]) * d_last_sample; // Error calculation
d_last_sample = out[oo];
//Loop filtering
d_omega = d_omega + d_gain_omega * mm_val; //Frequency
d_omega = d_omega_mid + gr::branchless_clip(d_omega-d_omega_mid, d_omega_lim); //Bound the frequency
d_mu = d_mu + d_omega + d_gain_mu * mm_val; //Phase
ii += (int)floor(d_mu); // Basepoint index
d_mu = d_mu - floor(d_mu); // Fractional interval
oo++;
}
consume_each(ii);
return oo;
}
Here is my code. First, the control loop is initialized the constructor
loop(new gr::blocks::control_loop(0.02,(1 + d_omega_relative_limit)*omega,
(1 - d_omega_relative_limit)*omega))
First of all I would like to eliminate a couple of doubts that I have regarding pll (the control_loop above) in symbol timing recovery particularly phase and frequency ranges (that are in turn used for wrapping). Taking an analogy from Costas loop : carrier phase is wrapped between -2pi and +2pi and the frequency offset is tracked between -1 and +1. It is quite straightforward to see why. Unfortunately I can't get my head around phase and frequency tracking in symbol recovery. From the m&m block, frequency is tracked between (1+omega_relative_limit) and (1 - omega_relative_limit)*omega where omega is simply the number of samples per symbol. Phase is tracked between 0 and omega. I dont understand why this is so and why the m&m block doesn't wrap it. Any ideas here will be appreciated.
And here is my work function
debug_time_recovery_pam_test_1_impl::general_work (int noutput_items,
gr_vector_int &ninput_items,
gr_vector_const_void_star &input_items,
gr_vector_void_star &output_items)
{
// Tell runtime system how many output items we produced.
const float *in = (const float *)input_items[0];
float *out = (float *)output_items[0];
int ii = 0; // input index
int oo = 0; // output index
int ni = ninput_items[0] - d_interp->ntaps(); // don't use more input than this
float mm_val;
while(oo < noutput_items && ii < ni ) {
// produce output sample
out[oo] = d_interp->interpolate(&in[ii], d_mu);
//Calculating error
mm_val = slice(d_last_sample) * out[oo] - slice(out[oo]) * d_last_sample;
d_last_sample = out[oo];
//Loop filtering
loop->advance_loop(mm_val); // Filter the error
loop->frequency_limit(); //Stop frequency from wandering too far
//Loop phase and frequency
d_omega = loop->get_frequency();
d_mu = loop->get_phase();
//d_omega = d_omega + d_gain_omega * mm_val;
//d_omega = d_omega_mid + gr::branchless_clip(d_omega-d_omega_mid, d_omega_lim);
//d_mu = d_mu + d_omega + d_gain_mu * mm_val;
ii += (int)floor(d_mu); // Basepoint index
d_mu = d_mu - floor(d_mu);//Fractional interval
oo++;
}
consume_each(ii);
return oo;
}
I have tried to use the block in a GFSK demodulator and I got this error
python: /build/gnuradio-bJXzXK/gnuradio-3.7.9.1/gnuradio-runtime/include/gnuradio/buffer.h:177: unsigned int gr::buffer::index_add(unsigned int, unsigned int): Assertion `s < d_bufsize' failed.
The first google search regarding this error suggests that im somehow "abusing" the scheduler since this error comes somewhere below the API. I think my calculation of d_omega and d_mu from the control loop is a bit naive but unfortunately I don't know any other way of doing so. Another alternative will be to use a modulo-1 counter (incrementing or decrementing) but I want to explore this option first.
Im trying to make a toString method that prints out a histogram that shows how often each character of the alphabet is used in a string. The most frequent character has to be 60 #s long, with the rest of the characters then scaled to match.
My issue is with making the equation that scales the rest of the letters to the correct length for the histogram. My current equation is (myArray[i]/max) * 60, but im getting really weird results.
If I put in "hello world" to be analyzed, L would be the most common occuring letter, seen 3 times. So L should have 60 #s for the histogram, h should have 20, o should have 40 etc. Instead im getting results like d : 10
e : 10
h : 10
l : 360
o : 20
r : 10
w : 10
Sorry for how sloppy this is right now, im just trying to figure out whats going on
public class LetterCounter
private static int[] alphabetArray;
private static String input;
/**
* Constructor for objects of class LetterCounter
*/
public LetterCounter()
{
alphabetArray = new int[26];
}
public void countLetters(String input) {
this.input = input;
this.input.toLowerCase();
//String s= input;
//s.toLowerCase();
for ( int i = 0; i < input.length(); i++ ) {
char ch= input.charAt(i);
if (ch >= 97 && ch <= 122){
alphabetArray[ch-'a']++;
}
}
}
public void getTotalCount() {
for (int i = 0; i < alphabetArray.length; i++) {
if(alphabetArray[i]>=0){
char ch = (char) (i+97);
System.out.println(ch +" : "+alphabetArray[i]);
}
}
}
public void reset() {
for (int i =0; i<alphabetArray.length; i++) {
if(alphabetArray[i]>=0){
alphabetArray[i]=0;
char ch = (char) (i+97);
System.out.println(ch +" : "+alphabetArray[i]);
}
}
}
public String toString() {
String s = "";
int max = alphabetArray[0];
int markCounter = 0;
for(int i =0; i<alphabetArray.length; i++) {
//finds the largest number of occurences for any letter in the string
if(alphabetArray[i] > max) {
max = alphabetArray[i];
}
}
for(int i =0; i<alphabetArray.length; i++) {
//trying to scale the rest of the characters down here
if(alphabetArray[i] > 0) {
markCounter = (alphabetArray[i] / max) * 60;
char ch = (char) (i+97);
System.out.println(ch +" : "+alphabetArray[i] + markCounter);
}
}
for (int i = 0; i < alphabetArray.length; i++) {
//prints the whole alphabet, total number of occurences for all chars
if(alphabetArray[i]>=0){
char ch = (char) (i+97);
System.out.println(ch +" : "+alphabetArray[i]);
}
}
return s;
}
}
There are many many problems with your code, but lets go one by one.
First of all, your print statement is simply misleading. Change it to
System.out.println(ch +" : "+alphabetArray[i] + " " + markCounter);
and you will see
d : 1 0
e : 1 0
h : 1 0
l : 3 60
o : 2 0
r : 1 0
w : 1 0
As you can see: the counters are correct (1,1,1,3,2,1,1). But the your scaling doesn't work:
1 / 3 --> 0 ... and 0 * 3 ... is still 0
3 / 3 --> 1 and 1 * 3 ... is 60
but of course, when you dont print a space between 1 and 0 and 3 and 60.
Thus to get correct scaling, just change to:
markCounter = alphabetArray[i] * 60 / max;
Other things worth mentioning:
You are overriding toString(). Then you should put #Override in fron t of that method
toLowerCase() returns a new string in lower case; just calling it without pushing the result back into your string ... just throws away the "lower casing".
toString() shouldnt print to the console. The whole idea is that you put all the information into the string that you return. In other words: in the end you do some System.out.println(someLetterCounter.toString()
Your code is extremely low-level. You don't iterate arrays using for (int), you can do (int letter : alphabetArray) instead
You might want to read about Map. You see, if you would be using a Map<Character, Integer> where the map key would represent the different characters, and the map value represents a counter for each character ... well, you could throw out most of your code; and come up with a solution that would require a few lines of code only!
( and seriously: because of all these issues, debugging your code was really much harder than it needed to be )
countLetters seems has some issues. You can not convert String to lowercase by just calling
this.input.toLowerCase();
Because String is immutable in java. You have to assign it like:
this.input = input.toLowerCase();
Another problem is you are using input variable from parameter instead of this.input which has lower case string. You can do this way to make work countLetters method:
public void countLetters(String input) {
this.input = input.toLowerCase();
for ( int i = 0; i < this.input.length(); i++ ) {
char ch= this.input.charAt(i);
if (ch >= 97 && ch <= 122) {
alphabetArray[ch-'a']++;
}
}
}
I am currently trying some simple (ready) programs from Arduino examples regardin the ethernet shield. I am still getting no result. Am always receiving that I am not connected or a blank serial monitor. Does anyone knows why? I think I am connected to the DHCP since i am on the DHCP list of my router
<#include <SPI.h>
#include <Ethernet.h>
#include <EthernetUdp.h>
// Enter a MAC address for your controller below.
// Newer Ethernet shields have a MAC address printed on a sticker on the shield
byte mac[] = {
0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED
};
unsigned int localPort = 8888; // local port to listen for UDP packets
IPAddress timeServer(192, 43, 244, 18); // time.nist.gov NTP server
const int NTP_PACKET_SIZE = 48; // NTP time stamp is in the first 48 bytes of the message
byte packetBuffer[ NTP_PACKET_SIZE]; //buffer to hold incoming and outgoing packets
// A UDP instance to let us send and receive packets over UDP
EthernetUDP Udp;
void setup()
{
// Open serial communications and wait for port to open:
Serial.begin(9600);
while (!Serial) {
; // wait for serial port to connect. Needed for Leonardo only
}
// start Ethernet and UDP
if (Ethernet.begin(mac) == 0) {
Serial.println("Failed to configure Ethernet using DHCP");
// no point in carrying on, so do nothing forevermore:
for (;;)
;
}
Udp.begin(localPort);
}
void loop()
{
sendNTPpacket(timeServer); // send an NTP packet to a time server
// wait to see if a reply is available
delay(1000);
if ( Udp.parsePacket() ) {
// We've received a packet, read the data from it
Udp.read(packetBuffer, NTP_PACKET_SIZE); // read the packet into the buffer
//the timestamp starts at byte 40 of the received packet and is four bytes,
// or two words, long. First, esxtract the two words:
unsigned long highWord = word(packetBuffer[40], packetBuffer[41]);
unsigned long lowWord = word(packetBuffer[42], packetBuffer[43]);
// combine the four bytes (two words) into a long integer
// this is NTP time (seconds since Jan 1 1900):
unsigned long secsSince1900 = highWord << 16 | lowWord;
Serial.print("Seconds since Jan 1 1900 = " );
Serial.println(secsSince1900);
// now convert NTP time into everyday time:
Serial.print("Unix time = ");
// Unix time starts on Jan 1 1970. In seconds, that's 2208988800:
const unsigned long seventyYears = 2208988800UL;
// subtract seventy years:
unsigned long epoch = secsSince1900 - seventyYears;
// print Unix time:
Serial.println(epoch);
// print the hour, minute and second:
Serial.print("The UTC time is "); // UTC is the time at Greenwich Meridian (GMT)
Serial.print((epoch % 86400L) / 3600); // print the hour (86400 equals secs per day)
Serial.print(':');
if ( ((epoch % 3600) / 60) < 10 ) {
// In the first 10 minutes of each hour, we'll want a leading '0'
Serial.print('0');
}
Serial.print((epoch % 3600) / 60); // print the minute (3600 equals secs per minute)
Serial.print(':');
if ( (epoch % 60) < 10 ) {
// In the first 10 seconds of each minute, we'll want a leading '0'
Serial.print('0');
}
Serial.println(epoch % 60); // print the second
}
// wait ten seconds before asking for the time again
delay(10000);
}
// send an NTP request to the time server at the given address
unsigned long sendNTPpacket(IPAddress& address)
{
// set all bytes in the buffer to 0
memset(packetBuffer, 0, NTP_PACKET_SIZE);
// Initialize values needed to form NTP request
// (see URL above for details on the packets)
packetBuffer[0] = 0b11100011; // LI, Version, Mode
packetBuffer[1] = 0; // Stratum, or type of clock
packetBuffer[2] = 6; // Polling Interval
packetBuffer[3] = 0xEC; // Peer Clock Precision
// 8 bytes of zero for Root Delay & Root Dispersion
packetBuffer[12] = 49;
packetBuffer[13] = 0x4E;
packetBuffer[14] = 49;
packetBuffer[15] = 52;
// all NTP fields have been given values, now
// you can send a packet requesting a timestamp:
Udp.beginPacket(address, 123); //NTP requests are to port 123
Udp.write(packetBuffer, NTP_PACKET_SIZE);
Udp.endPacket();
}
If your ethernet shield is a cheap clone, they are known to be faulty.
You will be able to get a DHCP address by plugging it directly into your DHCP server, but you will not get an address if the shield is connected to a switch.
You can fix this by soldering 2 x 100 Ohm resistors to the correct pins of the network socket on the bottom of the shield.
Alternatively, use a static ip address, or buy a different ethernet shield.
I am trying to create a software simulation on an Ubuntu GNU/Linux machine which will work like PPPoE. I would like this simulator to take outgoing packets, strip off the ethernet header, insert the PPP flags (7E, FF, 03, 00, and 21) and place the IP layer information in the PPP packet. I am having trouble with the FCS that goes after the data. From what I can tell, the cell modem I am using has a 2 byte FCS using the CRC16-CCITT method. I have found several pieces of software that will calculate this checksum, but none of them produce what is coming out the serial line (I have a serial line "sniffer" that shows me everything the modem is being sent).
I have been looking into the source of pppd and the linux kernel itself, and I can see that both of them have a method of adding an FCS to the data. It seems quite difficult to implement, as I have no experience in kernel hacking. Can someone come up with a simple way (preferably in Python) of calculating an FCS that matches the one that the kernel produces?
Thanks.
P.S. If anyone wants, I can add a sample of the data output I am getting to the serial modem.
Used simple python library crcmod.
import crcmod #pip3 install crcmod
fcsData = "A0 19 03 61 DC"
fcsData=''.join(fcsData.split(' '))
print(fcsData)
crc16 = crcmod.mkCrcFun(0x11021, rev=True,initCrc=0x0000, xorOut=0xFFFF)
print(hex(crc16(bytes.fromhex(fcsData))))
fcs=hex(crc16(bytes.fromhex(fcsData)))
I recently did something like this while testing code to kill a ppp connection ..
This worked for me:
# RFC 1662 Appendix C
def mkfcstab():
P = 0x8408
def valiter():
for b in range(256):
v = b
i = 8
while i:
v = (v >> 1) ^ P if v & 1 else v >> 1
i -= 1
yield v & 0xFFFF
return tuple(valiter())
fcstab = mkfcstab()
PPPINITFCS16 = 0xffff # Initial FCS value
PPPGOODFCS16 = 0xf0b8 # Good final FCS value
def pppfcs16(fcs, bytelist):
for b in bytelist:
fcs = (fcs >> 8) ^ fcstab[(fcs ^ b) & 0xff]
return fcs
To get the value:
fcs = pppfcs16(PPPINITFCS16, (ord(c) for c in frame)) ^ 0xFFFF
and swap the bytes (I used chr((fcs & 0xFF00) >> 8), chr(fcs & 0x00FF))
Got this from mbed.org PPP-Blinky:
// http://www.sunshine2k.de/coding/javascript/crc/crc_js.html - Correctly calculates
// the 16-bit FCS (crc) on our frames (Choose CRC16_CCITT_FALSE)
int crc;
void crcReset()
{
crc=0xffff; // crc restart
}
void crcDo(int x) // cumulative crc
{
for (int i=0; i<8; i++) {
crc=((crc&1)^(x&1))?(crc>>1)^0x8408:crc>>1; // crc calculator
x>>=1;
}
}
int crcBuf(char * buf, int size) // crc on an entire block of memory
{
crcReset();
for(int i=0; i<size; i++)crcDo(*buf++);
return crc;
}