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Ligne 198 :
Ligne 198 : + + + + + + + + + + + − + Ligne 209 :
Ligne 220 : − + − // convert voltage to temperature − // Degrees = (voltage - 500mV) multiplied by 100 Ligne 221 :
Ligne 230 : − +
ENG-CANSAT-MISSION1-CAPTURE (voir la source)
Version du 29 octobre 2018 à 21:09
, 29 octobre 2018 à 21:09→The code explained
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</syntaxhighlight>
Now, we can focus on the main loop.
The first step is to send the header if not done yet.
Then we reads the sensors (as we have tested them, this should not be a surprise). We also capture the time with the function {{fname|millis()}}, so the {{fname|ms}} variable contains the number of milliseconds since the last reset.
Finally, we do increment the {{fname|packetnum}} variable. This would allows to track lost packets on the receiver side.
{{fname|packet_str}} is the message to send via radio. It is composed with {{fname|String}} objects and concatenation operations. {{fname|String}} are welcome to transform '''float''' into string representation since most common float to string C standard functions would fail to work properly onto Arduino alike plateforms.
The key function to transform the '''String object''' into a '''C buffer'' is {{fname|packet_str.c_str()}} which offer an access to the underlying array of bytes (exactly what we would need for the radio module library).
<syntaxhighlight lang="c">
<syntaxhighlight lang="c">
bool header_send = false; // if header has not been send yet...
bool header_send = false; // if header has not been send yet...
int16_t packetnum = 0; // packet number increment at each data emission
int16_t packetnum = 0; // packet number increment at each data emission
void loop() {
void loop() {
// send columns header
// --- SEND COLUMNS HEADER -------------------
if( !(header_send) ){
if( !(header_send) ){
send_header();
send_header();
}
}
// read the voltage of TMP36
// --- READ SENSORS ---------------------------
float voltage = getVoltage(temperaturePin);
float voltage = getVoltage(temperaturePin);
float temperature = (voltage - .5) *100;
float temperature = (voltage - .5) *100;
packetnum += 1; // increment
packetnum += 1; // increment
// char radiopacket[40] = "Hello World #";
// --- Compose the Message to send ------------
String packet_str = String( ":"+String(packetnum,DEC)+"|" );
String packet_str = String( ":"+String(packetnum,DEC)+"|" );
packet_str.concat( String(ms,DEC)+"|" );
packet_str.concat( String(ms,DEC)+"|" );