I agree with you that most the time it's user error (my error).
I only asked if there was some bug in the library for the 3.3v version of Mini Pro.
Anyway, this is my project:
My project is "StarFinder" : finding stars with Stellarium on Maemo5/NOKIA900 and a Green Laser
In this image you can see Stellarium on Nokia900, modded and recompiled to talk with arduino.
The wireless communication is done with Bluesmirf Silver.
To find the Stars ia use an AHRS 9DOF, implemented with with the sparkfun breakout board (75 Euros!) and
the GREAT Sebastian O.H. Madgwick code.
The feedback is done with a great ULCD144 GOLDELOX lcd screen. Only for debugging i use a cheap Nokia 5110.
I had problems sharing the uart between the Sensor and the ULCD144 (i tried a multiplexer, but didn't like it).
So i have bought a sparkfun SPI<->UART to talk to the lcd.
You can also see the OLS Sniffer, i have used to sniff the TX, RX lines
In this second image you can see the garbage i read on RX, displayed on the Debugging LCD.
In this fourth image you can see the INCREDIBLE ULCD144! It cost about 30 Euros, and it's really great!
In this fifth image you can see the sniff of the TX line. When i push the button for 3 seconds, StarFinder start "calibration mode", and send the bytes "MOON " to Stellarium on Nokia900. Stellarium search the position of the Moon, or some other Visible Star : Sirius, Polaris, Vega, etc... and send the Triple (Name 10 bytes, yaw 2 bytes, pitch 2 byte) = total 14 bytes to Arduino.
In this last image you can see the sniff of the RX line : the answer from Stellarium/Nokia900 to StarFinder/Arduino. The stream of bytes "seem" good : "Polaris YYPP" (YY = two bytes for yaw MSB, PP = two bytes for pitch MSB). The Moon was not visible, and Stellarium looked for Polaris Star.
...Oh! The Laser... here it is, modded and ready for a PCB.
And this is some code from the sketch. The problem is inside the method "moonFound". The commented code use the method Serial.available(), but it return 0 (displayed on the debugging LCD). The debugging code read one byte at time, when it's available, and "return true" to the caller only when 14 bytes has been collected (name, yaw, pitch)
The UART, Nokia, BT etc... all works at 115200 baud
// "finder" is the App Object
void setup() { finder.init(9/*button*/, 8/*lcd_ok*/, 10/*spi_select*/); }
void loop() { finder.update(); }
class StarFinder
{
inline void init(byte pin_button, byte lcd_avail, byte spi_select)
{
int i;
Serial.begin(115200);
[...]
}
[...]
inline void update()
{
update_ahrs();
button.update(s);
switch (stato)
{
case Compass:
{
[...]
if (button.pushed(s)) stato = Moon_Calibrate;
[...]
break;
}
[...]
case Moon_Calibrate:
{
stellarium.searchMoon();
last_millis_stellarium_calibrate = millis();
stato = Moon_Calibrate_Wait_Answer;
break;
}
case Moon_Calibrate_Wait_Answer:
{
if (millis() - last_millis_stellarium_calibrate > 3000)
{
stato = No_Answer_from_Stellarium;
break;
}
if (stellarium.moonFound(yaw_moon_real, pitch_moon_real, moon_name))
stato = Moon_Calibrate_Ask_Clik;
break;
}
[...]
} // end class StarFinder
class NOKIA900 // That is "stellarium" object
{
[...]
inline bool moonFound(int& yawm, int& pitchm, char* name)
{
//*** Start of debugging code
static int lbuf = 0;
static char buf[14];
byte f = Serial.read();
if (f == -1) return false;
buf[lbuf++] = f;
if (lbuf < calibration_length) return false;
lbuf = 0;
strncpy(name, buf, 10);
yawm = ( (buf[10]<<8) & 0xFF00 );
yawm = yawm | ( buf[11] & 0x00FF );
pitchm = ( (buf[12]<<8) & 0xFF00 );
pitchm = pitchm | ( buf[13] & 0x00FF );
lcd.clean();
lcd.prints("Hello");
lcd.prints(name,2);
char t[10];
return true;
//*** End of debuging code
//*** Start of preferred code
int n = Serial.available();
if (n < calibration_length) return false;
if (n > calibration_length)
{
Serial.flush();
return false;
}
for (int i=0; i<10; ++i)
name[i] = Serial.read();
byte c = Serial.read();
yawm = ( (c<<8) & 0xFF00 );
c = Serial.read();
yawm = yawm | ( c & 0x00FF );
c = Serial.read();
pitchm = ( (c<<8) & 0xFF00 );
c = Serial.read();
pitchm = pitchm | ( c & 0x00FF );
return true;
//*** end of preferred code
}
[...]
}
It's an impressive-looking project. I was thinking of getting a telescope that is computer-controlled and you seem to have gone a long way down that path.
I can't comment on the library per se, but I am a bit doubtful of the code snippets you have shown. To really comment I need to see the lot, as the excerpted stuff hides a lot of relevant detail. For example, what is calibration_length?
I'm a bit concerned about this:
//*** Start of preferred code
int n = Serial.available();
if (n < calibration_length) return false;
if (n > calibration_length)
{
Serial.flush();
return false;
}
First, how do you know Serial.available() returns zero? And of course it will for a while until the data arrives.
Then you are checking for an exact number of bytes (calibration_length whatever that is). If you get a single extra one (eg. a newline character) then you throw the whole lot away. That could account for appearing to get nothing. And at that speed of transmission the extra byte might arrive quite fast. It would be better, I think, to wait for calibration_length bytes, process them all, and then, if you must, flush away any extra ones.
I have solved my problem, but have edited my first post.
I have done more debugging, using the Serial port of the PC, an RS232/TTL Adapter, the sniffer etc etc...
I did a stupid error in the debugging code (not in the orginal code): i wrote char f = Serial.read(), but of course
i must write int f = Serial.read(), to test for available data.
Then i have seen many errors reading at 115200 baud : i have reduced the baud rate to 57600 in the sketch, the BlueSmirf, and the Nokia, and it's realy better.
During the tests, i have always invoked Serial.available() (before Serial.read() of course), but it has always returned 0 (displayed to the Nokia 5110 debugging LCD, and to sscom32 serial program under Windows XP)
Now i don't use Serial.avilable(), my modified code is working fine :
int f = Serial.read();
// if no data available, do nothing, and go on updating the DCM filter in the mail loop
if (f == -1) return false;
// if there is some data, i read only 1 char (it's not important trying to read immediately all the data available)
buf[lbuf++] = (char)f;
// if i have NOT collected the whole packet, do nothing and go on updating the DCM filter in the mail loop
// ( FIXED packet size from Nokia! This is the answer to the instruction [...] if (n > calibration_length) ... [...]
// i can't accept more characters than expected, there was some problem. )
if (lbuf < calibration_length) return false;
// if have collectet the whole packet from Nokia, finally answer to the caller to go to next STATUS
lbuf = 0;
strncpy(name, (char*)buf, 10);
yawm = ( (buf[10]<<8) & 0xFF00 );
yawm = yawm | ( buf[11] & 0x00FF );
pitchm = ( (buf[12]<<8) & 0xFF00 );
pitchm = pitchm | ( buf[13] & 0x00FF );
return true;
If you want to buy a telescope, maybe Stellarium could be a good choice for you. It is an Open Source, and i know it has plugins to CONTROL telescopes! The bad news is that is has been recompiled only under Nokia900 (for Mobile), and not under Android, and Nokia900 is NOT cheap! (I have bought my Nokia900 on eBay for 300 Euros)
