I finally got time to read the whole thread, and sadly realized that Tacho will not work as CLC (close loop control) component with SG4 PCU. So, I looked for Falcon PSU and see no sales, anywhere. Manufacture site is not working. Do you guys know any location when I can acquire that magic unit? Little out of that thread subject scope: Pyramid clarified about substitute for SG4 AMP in dedicated thread. So, I'm good for that perspective.
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I have the same one. TM1637 for Arduino . I guess I need the code? Progress is slow now that my Power amp blew.
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Hello all,
I've built a couple of these for friends. What occurred to me after I programmed them, the new ones display different reading compared to my earliest build which I've been using all the while. I had thought all would be identical but that doesn't seem the case. The reading vary to 33.5, 33.8 or even 33.1. This means not all Arduino Uno are exactly identical in performance out of the box. I'm using genuine Arduino, not compatibles.
I have to alter and vary the calibration frequency to have better accuracy.
"const float CALIBRATE = 1873440; //* equals freq @ PB2 x 120
I don't have any test gear to measure the crystal output so its trial and error with different calibration figures.
If your Arduino UNO reads accurately out of the box with suggested calibrate setting,then you're lucky. I always suspected my 1st tacho could be a little off but can't compare till I built another 2 units.
I've built a couple of these for friends. What occurred to me after I programmed them, the new ones display different reading compared to my earliest build which I've been using all the while. I had thought all would be identical but that doesn't seem the case. The reading vary to 33.5, 33.8 or even 33.1. This means not all Arduino Uno are exactly identical in performance out of the box. I'm using genuine Arduino, not compatibles.
I have to alter and vary the calibration frequency to have better accuracy.
"const float CALIBRATE = 1873440; //* equals freq @ PB2 x 120
I don't have any test gear to measure the crystal output so its trial and error with different calibration figures.
If your Arduino UNO reads accurately out of the box with suggested calibrate setting,then you're lucky. I always suspected my 1st tacho could be a little off but can't compare till I built another 2 units.
Hi,
Just a suggestion for the members of this thread there is an application that will run in your cell phone and will read your turntable rpm. I used it when building my rpm detector and it worked very good. The rpm compared with the reading from the sensor. You need to check if your cell phone can use it. Just drop the cell in the platten and let it goes around until it display the rpm. Check to see if they have the application your cell phone in the play store and it is free.
Just a suggestion for the members of this thread there is an application that will run in your cell phone and will read your turntable rpm. I used it when building my rpm detector and it worked very good. The rpm compared with the reading from the sensor. You need to check if your cell phone can use it. Just drop the cell in the platten and let it goes around until it display the rpm. Check to see if they have the application your cell phone in the play store and it is free.
RPM calculator is well and good but up to a point and a useful utility. I reckon its as accurate as the phone internal gyroscope would allow. If for any reason the phone gyroscope is not optimum, it may show misleading readings. I guess its better than nothing. I had to use "secret" codes to invoke hidden test routines to check or calibrate the gyroscope just to be sure, then hope for the best.
Thats dissapointing. Mine is built from a clone. I read 33.28 on my Denon dp-57m. I checked it against a chinese handheld tach and it reads correctly to 1 decimal. Has anyone else tried calibrating it?
Kffern
Man, something is screwy with my subscriptions on this board. They keep getting lost for this thread. WTF?
For those of us without the proper test gear, is there an inexpensive piece of equipment that we could pick up to (reliably) measure the frequency at PB2 in order to properly configure our Arduino boards?
Would this work accurately, I wouldn't know. Its cheap enough to pickup and try. I may do just that but it takes 3 weeks to be delivered.
Build something to test something.
Digital LED 1Hz-50MHz Crystal Oscillator Frequency Counter Meter Tester DIY Kits 629768592376 | eBay
Lee
I'll double-check mine later, but I don't think mine has a frequency measurement. Does look like there's some $20 or so ones that do, so that's not too bad. Good to have a better one anyway. I just can't practically justify a $100+ device at this level of hobby work.
Because the speed of rotation is fixed, at the outer groove the velocity (in feet/meter per second) is higher than at the inner groove. Basically one revolution travels a longer path at the outer groove. The inner groove requires less torque from the platter drive. If the losses in the system were zero, there would be no difference, but because the losses are zero + [something] any change in value [something] results in a speed change.
As far as explaining the reason for the difference, the value [something] isn't relevant except insofar that it's greater than zero. But if you were to try to minimize the difference, it would be useful to attribute it to some specific issue. Bearing friction, drive slippage, lack of motor torque, and stylus drag are all possible candidates.
Note that stylus drag will not be a constant, but will vary depending on the program material the stylus is reading from the record groove. But it's effect can be minimized or eliminated by improving the other parameters, especially motor torque and drive slippage. Bearing friction would also have an effect, but in most modern turntables it is already quite low and would be difficult to improve substantially.
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It's probably better for you to build one yourself, in case something gets disconnected and you need to figure out how to restore it. There's no risk of injury, which is why I felt comfortable trying this, whereas I still have no tutor for soldering, so I'm not yet comfortable with projects involving power supplies.
This might actually be a good starting point, too: SainSmart UNO + Sensor V5 + IIC LCD1602 Y-G Module Display For Arduino – SainSmart.com
The documentation on the Sensor Shield states that the COM ports are RS232, so that would eliminate the need for the kludgy extra hardware I used for interfacing with the Falcon. The above kit would provide Arduino, LCD, sensor board, and USB cable. If it does provide the correct serial connection, you'd just need to supply separate power, a headphone cable to connect to the Falcon, and a decent sensor and trigger (either magnet for hall sensor or reflective strip for IR sensor). I might give this a try some day, to see if I can come up with a less messy version.