2MS DATV from Raspberry Pi

[g0mjw]

Has anyone managed to get the original DigiThin board to operate with the new software ?
I thought at first the problem I was getting was down to I and Q rooting but that does not appear to be the case. I am not sure the Pic is receiving the correct information. The board works fine with the old software.

Arthur G4CPE

I and Q are OK but there is nothing coming out of the PIC. At least not reliably - once or twice I got something. I gave up in the end and modified the box I had made to fit a newer PI2. That didn't work either so I am using the newer digilite board.

Mike

[G0EID]

In Jessie the UART, which is used to communicate with the PIC on the DIGITHIN, is configured as a serial console port.
The serial console needs to be disabled.
You can disable the serial console using `sudo raspi-config`
Advanced Options -> Serial
Exit raspi-config, then edit /boot/cmdline.txt
Change the line from:
dwc_otg.lpm_enable=0 console=serial0,115200 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait
To:
dwc_otg.lpm_enable=0 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait plymouth.ignore-serial-consoles

Disabling the serial port using raspi-config, will have disabled the UART device, so we need to re-enable it so that the DIGITHIN can use it instead.
Edit /boot/config.txt
Change:
enable_uart=0
To:
enable_uart=1

After you have rebooted.

Try `cat /dev/ttyAMA0`
You should see the "Hello.., Hello..." messages coming back from PIC on the DIGITHIN board.
Use CTRL-C to break out of cat commmand.

73
Dave - G0EID

[G4CPE]

Wow it works. Thanks Dave I would never have been able to sort that. DihiThin and old Raspberry Pi now working on new software
I noted the time of your post, I had not realized there were two 2 o clocks in one day. :

73 Arthur

[arthur21]

Success thanks Dave.

Arthur G4CPE

[arthur21]

I find the early Pi struggles a bit with the EasyCap grabber. I have two of these, one device works better than the other but both OK on RPI3.
Might tinker with over clocking on the old Pi I have several of them.

G4CPE

[g0mjw]

In Jessie the UART, which is used to communicate with the PIC on the DIGITHIN, is configured as a serial console port.
The serial console needs to be disabled.
You can disable the serial console using `sudo raspi-config`
Advanced Options -> Serial
Exit raspi-config, then edit /boot/cmdline.txt
Change the line from:
dwc_otg.lpm_enable=0 console=serial0,115200 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait
To:
dwc_otg.lpm_enable=0 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait plymouth.ignore-serial-consoles

Disabling the serial port using raspi-config, will have disabled the UART device, so we need to re-enable it so that the DIGITHIN can use it instead.
Edit /boot/config.txt
Change:
enable_uart=0
To:
enable_uart=1

After you have rebooted.

Try `cat /dev/ttyAMA0`
You should see the "Hello.., Hello..." messages coming back from PIC on the DIGITHIN board.
Use CTRL-C to break out of cat commmand.

73
Dave - G0EID

Thanks Dave - that has made my PI2 work with the original Digithin. I didn't know about that test command - how did you find it?

[G4CPE]

With the latest software and a Pi3 into an RBTVMOD every symbol rate except 125ks/s is OK but when I select 125ks/s the bandwidth of the spectrum does not appear to change.

[MN-tech]

Monitor the I or Q signal with a scope. The period should double when you switch from 250 to 125.
You can monitor the frequency of the filter clock on the RBTVMOD board CLK test point. It's 16 times the SR. It should halve when you change from 250 to 125.
This should help you determine where the fault is. Could your spectrum anayzer be lying to you?

John

[f5oeo]

Effectively since I change PLL from 500MHZ to 1GHZ, the division of 1GHZ/125K >4096 thus low symbolrate like 125KS is not supported. Will have to choose a different PLL function of SR : hope to fix it soon !

[G4CPE]

Thanks Evariste. I am pleased you have confirmed my test results re. 125ks/s. Your work on developing this project is much appreciated.

73 Arthur