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@20191218
Javascript Object
Implicit objects
var n = 5;
var myArray = [1,2,3]
vs
Explicit objects
using new
var today = new date();
alert(today.getFullYear());
var myAry = new Array(100);
digging in TG
telegram:
get Info of bot: https://api.telegram.org/bot/getme
SendMessage: http://api.telegram.org/bot/sendMessage?chat_id=&text=HelloFromESP8266
ReceiveMessage: https://api.telegram.org/bot/getUpdates
reply a message: /sendmessage?chat_id=1234567&text=yoyo&reply_to_message_id=454
sendphoto: –> get the file id first!!!
/sendphoto?chat_id=1234567&photo=AgADBQADxagxG6PpUVdHAwvYecQlGt2C-TIABAEAAwIAA20AA4XvAgABFgQ
Sendphoto with URL:
/sendphoto?chat_id=1234567&photo=https://www.canva.com/learn/wp-content/uploads/2018/11/best-free-stock-photos-tb-2640×1485.jpg
https://stackoverflow.com/questions/33126743/how-do-i-add-my-bot-to-a-channel
sendMessage?chat_id=@test&text=Testing%20if%20this%20works
Pointer and Address
int myVar = 8; // variable myVar store value
&myVar; //address of myVar
int *myPtr;
myPtr = &myVar; // pointer myPtr store address of myVar
*myPtr; //value of the address pointed by myPtr
| myVar | &myVar |
| *myPtr | myPtr |
| value => 23 | address => 0x1234 |
Dynamic array
int size; cin >> size;
int * pz = new int [size]; // dynamic binding, size set at run time
…
delete [] pz; // free memory when finished
| 1 | 2 |
| void swapr(int & a, int & b) // use references { int temp; temp = a; // use a, b for values of variables a = b; b = temp; } |
swapr(wallet1, wallet2); // pass variables |
| void swapp(int * p, int * q) // use pointers { int temp; temp = *p; // use *p, *q for values of variables *p = *q; *q = temp; } |
swapp(&wallet1, &wallet2); // pass addresses of variables |
| void swapv(int a, int b) // try using values { int temp; temp = a; // use a, b for values of variables a = b; b = temp; } |
swapv(wallet1, wallet2); // pass values of variables |
C++ — String Object vs C-Style String
Two way to manipulate string.
std::string
| String Object | C-Style Sting |
| #include “string” | #include “cstring” / “string.h” |
| string myStr = “Hello World”; | char myCharr[20] = “Hello World”; |
| str1 = str2; | strcpy(charr1, charr2); |
| str1 += str2; | strcat(charr1, charr2); |
| str.size() | strlen(charr) |
| getline(cin, str); | cin.getline(charr, 20); //20 – max len |
Advance C/C++ lang topics
// Here we can see that more than one variables
// are being used without reporting any error.
// That is because they are declared in the
// different namespaces and scopes.
#include <iostream>
using namespace std;
// Variable created inside namespace
namespace first
{
int val = 500;
}
// Global variable
int val = 100;
int main()
{
// Local variable
int val = 200;
// These variables can be accessed from
// outside the namespace using the scope
// operator ::
cout << first::val << ‘\n’;
return 0;
}
C++[] –> namespace is like a named-scope, so you can use it kind of like everywhere
CNU library
https://www.gnu.org/software/libc/manual/html_node/Getopt.html
More about C/C++ library
https://www.tutorialspoint.com/c_standard_library/index.htm
https://www.tutorialspoint.com/cpp_standard_library/index.htm
WSL (Windows Subsystem Linux)
on Windows 10: install via store
on Powershell: enter the command
Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Windows-Subsystem-Linux
To run linux command on cmd::::
wsl ls -la
wsl xxxxxxx
To run windows command on WSL:::::
cmd.exe /C dir
or
PING.exe , ipconfig.exe
(( this depended on if the command has file extension or a bat file.
Basic thing, telegram on NodeMCU
Example used: HTTPSRequest
/*
HTTP over TLS (HTTPS) example sketch
This example demonstrates how to use
WiFiClientSecure class to access HTTPS API.
We fetch and display the status of
esp8266/Arduino project continuous integration
build.
Limitations:
only RSA certificates
no support of Perfect Forward Secrecy (PFS)
TLSv1.2 is supported since version 2.4.0-rc1
Created by Ivan Grokhotkov, 2015.
This example is in public domain.
*/
telegram:
get Info of bot: https://api.telegram.org/bot<YOUR-BOT-TOKEN>/getme
SendMessage: http://api.telegram.org/bot<YOUR-BOT-TOKEN>/sendMessage?chat_id=<YOUR-CHATID>&text=HelloFromESP8266
ReceiveMessage: https://api.telegram.org/bot<YOUR-BOT-TOKEN>/getUpdates
On the NodeMCU: Since it is HTTPS –> I cannot find a way to used it with AT COMMAND
Programming to NodeMCU:
HTTPSRequest:
–>fingerprint[] –> inside the Chrome –> certificate –> detail –> thumb print
GPRS A9 Module AT Command list
https://wiki.ai-thinker.com/gprs
//
AT+CGDCONT=1,”IP”,”cmhk”<\r><\n>
AT+CGATT=1<\r><\n>
AT+CGACT=1,1<\r><\n>
//
AT+CDNSGIP=”erp.hkite.com”<\r><\n>
Test the DNS, and check with terminal
host -a erp.hkite.com
//Base station location
+CREG: 2,1,”00A0″,”0D37″<\r><\n>
<\r><\n>
OK<\r><\n>
MCC:454 -> HK//http://www.gpsspg.com/bs/mcc.htm
MNC: 12 -> CMHK//http://www.gpsspg.com/bs/mnc.htm
LAC: 160 -> 0xA0
CI:3383 -> 0xD37
Google Cloud AutoML test
Overview:
screenshot:
https://docs.google.com/presentation/d/1KCSoR_aG-yn_vPBYFlLTzQdBAlBcdQgRYp5zdgH5IFA/edit?usp=sharing
Cloud AutoML Vision Object Detection
https://cloud.google.com/vision/automl/object-detection/docs/?_ga=2.244268482.-671499862.1555384491
With my training data: https://cloud.google.com/vision/automl/object-detection/docs/prepare
Cenz Learning Centre 