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Setting time manually



i plan to use sck_beta_v0_8_6_SDCARD. now i am wondering what ways there are to set the RTC time.
i would like to have some command like “#data” or “set time update XXX\r” which as far as i understands sets the interval between updates.

a short search throw the source gave me the idea that sck_beta_v0_8_6 is doing a request to a “timeserver” (see WEBTIME and sckWIFItime() in ServerUpdate.ino)

is there any command to set the RTC time?
if not i would like to implement such a command. probably someone can give me some hints on how to do this.

looking forward to any hints :wink:



The time of the RTC is set during the programming of the Arduino. This time is set by your computer.


why do i see 2000-01-01 then?
does there something go wrong?
i uploaded sck_beta_v0_8_6_SDCARD.ino and sck_beta_v0_8_6.ino several times. the smartcitizen seems always to have 2000-01-01.

proably at “programming” the arduine connects to a timeserver via its wlan connection: its configuration seems to be in Constants.h ( sck_beta_v0_8_6 ) :
... // Time server request - EndPoint: char* WEBTIME[3]={ /*Servidor de tiempo*/ "GET /datetime HTTP/1.1 \ ", "Host: \ ", "User-Agent: SmartCitizen \ \ " }; ...

the code to get the time from the timeserver ‘’ seems to be here: :
... for(byte i = 0; i<3; i++) Serial1.print(WEBTIME[i]); //Requests to the server time ...

i would like to set time via some other interface if possible without having to connect to the internet. i think of some command over the usb interface like they are described here:


With this expression takes time, in the code sck_beta_v0_8_6_SDCARD.ino


The command list that you mention, is to change the time on the update of the sensors.


i just managed to change SDCARD version so far that it takes a time string from command line:


this script sends output of smartcitizens time server or system date to ttyACM:

servertime=$(wget -q -O-

this is the format smartcitizen likes the date:

systemtime=$(date +%Y,%-m,%-d,%-H,%-M,%-S#)
echo " servertime: $servertime"
echo "setting systemtime: $systemtime"
echo $systemtime | sed -e ‘s/UTC://g’ > /dev/ttyACM1

to do so i manipulated the loop() to listen on serial port:
if ( terminal_mode )
// read a line
while (Serial.available()) {
delay(3); //delay to allow buffer to fill
if (Serial.available() >0) {
char c =; //gets one byte from serial buffer
readLine += c; //makes the string readString
// this is what we get from:
// UTC:2014,7,3,20,41,27#

  // if line is not empty:
  if ( readLine != "" )
   // simulate the part of sckWIFItime without requesting the server:
  ok = sckRTCadjust(sckTOMtime(readLine));
  if ( ok )
      Serial.println("set time ok");

  readLine = "";


and added my sckTOMtime() that does the same as sckWIFItime() from ServerUpdate but without querying the timeserver:

char* sckTOMtime(String serverTime) {
boolean ok=false;
uint8_t count = 0;
//if (sckFindInResponse(“UTC:”, 2000))

char newChar;
byte offset = 0;
byte tomCounter = 0;
while (offset < TIME_BUFFER_SIZE) {
// read next char
newChar = serverTime.charAt(tomCounter);
//Serial.println(newChar, DEC);

  if (newChar == '#') {
    ok = true;
    buffer[offset] = '\\x00';
  else if (newChar != -1) {
    if (newChar==',') 
      if (count<2) buffer[offset]='-';
      else if (count>2) buffer[offset]=':';
      else buffer[offset]=' ';
    else buffer[offset] = newChar;


if (!ok)
buffer[0] = ‘#’;
buffer[1] = 0x00;

return buffer;

if i call my script i can set the time on arduino without being connected to the internet. the output looks like this:

Temperature: 2620.80 C RAW
Humidity: 2908.00 % RAW
Light: 14.20 lx
Battery: 100.00 %
Solar Panel: 0.00 V
Carbon Monxide: 0.00 kOhm
Nitrogen Dioxide: 0.00 kOhm
Noise: 0.00 mV
UTC: 2014-07-05 01:01:00

2014-7-5 1:1:18
set time ok
Temperature: 2621.60 C RAW
Humidity: 2901.60 % RAW
Light: 14.20 lx
Battery: 100.00 %
Solar Panel: 0.00 V
Carbon Monxide: 4.49 kOhm
Nitrogen Dioxide: 0.00 kOhm
Noise: 2.35 mV
UTC: 2014-07-05 01:02:17