reduce the distance / length of cable between Arduino and si570 to 10-20 mm
(i have problems with my generator like yours) with this project. also check
whether si570 appropriate under the description of Farhan.
On Thu, Dec 10, 2015 at 10:56 AM, Riccardo Montaguti <ricky451@xxxxxxxxxx>
wrote:
Yes all correct,
The unconnected cap was a try to get it working sightly decoupling the I2C
lines with 100pf capacitors, I've also added the electrolytic cap to try
get it working correctly with no luck
Today I've noticed that when I run the sweep command the sweeperino is
trying to sweep in fact on the scope the 56.32Mhz became a bit unstable and
switch off for a fraction of second but is not able to sweep correctly.
This problems seems to be a mistery
Riccardo
Il giorno 10/dic/2015, alle ore 00:01, Richard Hayter <
richardshayter@xxxxxxxxx> ha scritto:
Hi Riccardo
the only difference between our two Si570 versions relates to the
Temperature Stability and the Total Stability. Mine = 50ppm and 61.5ppm.
Yours = 7ppm and 20ppm respectively. Reference pg 32 of the specification.
Looking at the pic I seem to see an electrolytic cap on pin 6 of the
Si570? Should not make a difference but maybe it does?. Also a longer
unshielded lead from the Pad? Also seems to be a cap hanging in the air off
the pad? I assume you are feeding 3.3V to the Si570 rail? Correct?
72 Dick N4HAY
On Wed, Dec 9, 2015 at 5:05 PM, Riccardo Montaguti <ricky451@xxxxxxxxxx>
wrote:
Hi Richard,
First of all thank you very much for your patience!
I've attached the photo of my build,
My Si570 number is 570CCC000141DG purchased directly from SiLabs is a
CMOS 20ppm version could be this difference the problem?
<image1.JPG>
Il giorno 09/dic/2015, alle ore 22:52, Richard Hayter <
richardshayter@xxxxxxxxx> ha scritto:
Hi Riccardo,
some additional comments may assist. I was very careful to avoid ground
loops with my prototype. If you look at the pics I have a single point
ground post with a ground wire to that post from the Si570, the pots, the
LCD and the UNO.
Not sure if that makes a difference but I do note that the output level
of the Si570 with a 3.3V rail is quite significant. Recognizing that it is
a squarewave and thus calibration is off, I measured something like a
+15dBm output signal level on my separate AD8307 Power Meter.
73 de Dick N4HAY.
ZS6RSH.blogspot.com
On Wed, Dec 9, 2015 at 4:43 PM, Richard Hayter <richardshayter@xxxxxxxxx>
wrote:
Hi Riccardo,
in my prototype SWEEPERINO I am using Arduino UNO.
IDE is 1.6.5.
CMOS Si570. DIGIKEY P/N 336-2518-ND. Mfg P/N 570CAC000141DG
PULLUP Resistor values = 4.7K Ohms to the 3.3V power supply.
Frequency measurement. I monitored the Si570 generated RF signal
precisely using my K2 receiver which was set across the room. This
frequency compared exactly the same as the LCD readout displayed. When I
turned the tuning Pot the frequency changed according to expectation as
defined by Farhan in his writeup. I attached a small wire (to act as an
antenna) to the Si570 output BNC connector which was also terminated in a
50Ohm terminator. On boot up the starting frequency was in the 14.2MHz
range. I did not change any calibration parameters in the Arduino Sketch.
I am now building prototype number 2 using the NANO. Initially I had
issues with the NANO Driver. Eventually I got the NANO to accept an upload
once I got the CH340 Driver correctly loaded in my Laptop. My NANO is one
of the newer ones that uses the CH340 driver as opposed to the FTDI of
older NANO's.
I had issues with running the exec on my Windows 7 machine. Eventually
Farhan sent me a different version of the exec than the one on GITHUB. This
version works perfectly.
So far I have the NANO working just with the LCD connected. It displays
Sweeperino V2.0 correctly.
This evening I will connect the Si570 to the NANO and will also simulate
the RF Power Meter input with a potentiometer.
I am also attaching some pics of prototype 1 (using the UNO). Can you
see the small handmade breakout board I fashioned for the Si570?.
Some additional comments. I get exactly the same readout on the serial
monitor as you are seeing: ie
*Sweeperino v0.02
*Testing for Si570
Successfully initialized Si570
*Si570 ON
However I don't know what you mean by the Radiono output. How do you get
that to show on the serial monitor?
You may also be interested to note that I was never able to change the
frequency using an 'f' command on the serial monitor command line. I was
able to change the Si570 frequency with the pot no problem. I was also
able to sweep the frequency no problem using the executable.
I will report back on findings on that.
Hopefully this information will assist?
72 de Dick N4HAY
ZS6RSH.blogspot.com
On Wed, Dec 9, 2015 at 11:53 AM, Riccardo Montaguti <ricky451@xxxxxxxxxx
wrote:
Farhan, no my sweeperino doesn’t work properly because I see the
14.5Mhz frequency displayed on the LCD but by checking with scope the Si570
output I get a 56.32Mhz wave.
Dick could you please explain to me some more detail? What is the
pullups value? and what version of the arduino IDE are you using? Did you
check the Si570 output with a scope?
Thank you for the help
Riccardo
Il giorno 09/dic/2015, alle ore 16:51, Richard Hayter <
richardshayter@xxxxxxxxx> ha scritto:
Hello Riccardo,
I am also building a Sweeperino using CMOs version. I have a prototype
of it working. Startup frequency is in the 14mHz area. This is on the UNO.
Now I am also able to upload the code into the NANO. This evening I will be
connecting the Si570. I will let you know if I get it working.
73 Dick N4HAY
ZS6RSH.blogspot.com <http://zs6rsh.blogspot.com/>
On Wed, Dec 9, 2015 at 4:29 AM, Riccardo Montaguti <ricky451@xxxxxxxxxx
wrote:
Good morning,
I’m building a sweeperino because would be a very useful tool but I’m
having problems with the Si570.
I’ve uploaded an arduino nano with the code without getting errors but
when i connect the arduino to the si570 I can get only the 56.32Mhz
frequency even if the LCD display shows 14.5Mhz and also by tuning the
potentiometer.
I’ve checked by the arduino serial window and I get the following:
*Sweeperino v0.02
*Testing for Si570
Successfully initialized Si570
*Si570 ON
So I think the I2C is communicating but maybe there is a freeze in the
code.
By using the radiono program I have the same problem and I get in the
serial monitor this:
Radiono starting - Version: 0.4
Tests successful!
Successfully initialized Si570
--- Si570 Debug Info ---
Crystal frequency calibrated at: 20283316
Status: 1
Register[7] = e1
Register[8] = c2
Register[9] = b6
Register[10] = 2a
Register[11] = a5
Register[12] = 93
HsDivider = 11 N1 = 8
Reference Frequency (hex) : 0002b62aa593
Reference Frequency (double): 43.385
I’ve build the circuit exactly as the original schematic (I use 4.7K
pull-ups) and I’ve only changed the LCD pins to get it working properly.
Could someone please give me some advices? I’ve also tried to change
the Si570 but with no luck
Thank you for the kind attention
Riccardo Montaguti
