Last day’s I work on the Retrochallenge 2016/01 project to try to understand the FL1216 TV-Tuner. Last blog I told that I have a anwser from both I2C devices on the I2C-bus. Now I study the datasheet’s of the FL1216 and slowly I think I understand the working of it.
To set the FL1216 to a specific frequency you must send the following byte’s:
Adres_byte, Dividerbyte_1, Dividerbyte_2, Control_byte, Band_Byte
These byte’s have the following meaning:
- The Adres_byte have I set on &HC0 by put the pin 15 to GND
- De Dividerbyte_1 and Dividerbyte_2 I calculate from the datasheet by N = 20 * {fRF + 38.9} In this formule fRF is the picture frequentie and the 38.9 is the IF carrier. The result N is a 14-bit value which we store/split direct in two byte’s, the Dividerbyte_1 and Dividerbyte_2
- Control_byte. Here we set some stuff like scan speed and scan step.
- Band_Byte. We set the three differend band’s: Lowband, Midband and Highband.
Also you can read some information back from the FL1216. The most importend information is the status of the PLL-Lockbit. Also the power on reset bit can you read.
In my program for the Arduino-Nano I make a calculation for the necessary divider-byte’s, control and bandbyte and then I read the Status_byte back. The result is the following screen.
The first time I read the Status_byte back from the FL1216 I see the Power on Reset bit is set, so this is Oke. After a couple reading’s (time) I see the PLL Lockbit is set. This is also correct. When I set the Tuner on the next Frequency the PLL is very fast locked. this is also good because a wait a couple of mSec after a Frequency setting before I read the Status_byte back and the step’s are very little. When you move to a very different frequency the tuner need time to Lock the PLL. This I have also tested.
Conclusion for this time:
I can talk with the Philips FL1216 TV-Tuner. And it looks working as I expect. Next step is connect a good working RetroComputer with UHF output or a Game-console with a VHF-UHF output to this tuner and let me surprise.