moojuiceuk
Posts: 6
Joined: Sat Feb 07, 2015 1:10 am
Location: Southampton UK

Pi TV Hat questions

Fri Nov 23, 2018 12:46 am

Just got a Pi TV hat working - so far so good.

Does anyone know what the 2-pin header on the PCB is used for that I've circled in red below...?
pitv.jpg
pitv.jpg (31.93 KiB) Viewed 4685 times
Is it possible to use more than 1 tuner card stacked up? Can multiple devices share an SPI bus?

Can it also receive DAB radio streams? Looking at the spec, VHF Band III is supported (174 - 230MHz) which is the same frequency allocation as DAB in the UK. If so, what software is used for that?

Has anyone managed to exploit the Sony chip as a true SDR and if so, what frequencies can it cover?

noggin
Posts: 99
Joined: Sun Feb 21, 2016 1:55 pm

Re: Pi TV Hat questions

Sun Nov 25, 2018 12:00 pm

I asked. It's apparently for programming the HAT ID EEPROM with the correct contents during manufacture. Nothing useful for end users.

Official HATs have an ID EEPROM that is read via I2C so that the Pi knows which HAT is connected and loads the correct drivers/device tree?

ViacheslavGrytsyk
Posts: 2
Joined: Thu Jan 10, 2019 10:03 am

Re: Pi TV Hat questions

Fri Jan 11, 2019 9:56 am

Hello to All!

Can I get data from CXD2880 about Signal Quality such as MER (Modulation Error Ratio)? SNR (Signal-to-Noise Ratio) and CNR (Carrier-to-Noise Ratio) as additional parameters of quality. How if possible? Thanks!

jaket91
Posts: 1
Joined: Sun Jan 13, 2019 10:30 pm

Re: Pi TV Hat questions

Sun Jan 13, 2019 10:34 pm

Did anybody discover whether multiple TV hats can be connected to the GPIO of the same Pi?

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DougieLawson
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Re: Pi TV Hat questions

Mon Jan 14, 2019 1:29 am

jaket91 wrote:
Sun Jan 13, 2019 10:34 pm
Did anybody discover whether multiple TV hats can be connected to the GPIO of the same Pi?
They can't work because both would use the same SPI chip select/chip enable pin unless you can change the hardware (which isn't possible for a hobbyist).

If you look in https://github.com/raspberrypi/linux/bl ... verlay.dts you'll see which pins are used.
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JanSyk
Posts: 1
Joined: Sun Jan 20, 2019 6:39 pm

Re: Pi TV Hat questions

Sun Jan 20, 2019 7:04 pm

Hi
I´m solving similar problem with not working raspberry TV tuner
Actual configuration is:
RPi3 + hifiberry Digi+ and Raspberry TV tuner
If there is connected only RPi3 and raspberry TV tuner without hifiberry Digi + it is working, but all together I can´t see in TVheadend any tuners.
I think problem is how to switch raspberry TV tuner to second raspberry SPI port (Hifiberry also working over SPI)
My logs:
https://paste.osmc.tv/ehakidogol
Anybody have same configuration?
Thanks for your help
Jan

hippy
Posts: 6729
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Location: UK

Re: Pi TV Hat questions

Sun Jan 20, 2019 10:26 pm

DougieLawson wrote:
Mon Jan 14, 2019 1:29 am
jaket91 wrote:
Sun Jan 13, 2019 10:34 pm
Did anybody discover whether multiple TV hats can be connected to the GPIO of the same Pi?
They can't work because both would use the same SPI chip select/chip enable pin unless you can change the hardware (which isn't possible for a hobbyist).
I don't see why it isn't possible for a hobyist. Hardware-wise it would be easy enough to build a T-shaped strip-board / vero-board / PCB construct which routes GPIO to two or more tuners with separate SPI enable to each.. And there may be add-ons available which can do that.

As to whether any software would support that having done it; I have no idea.

cellipo
Posts: 1
Joined: Sat Sep 14, 2019 8:12 am

Re: Pi TV Hat questions

Sat Sep 14, 2019 8:22 am

JanSyk wrote:
Sun Jan 20, 2019 7:04 pm
Hi
I´m solving similar problem with not working raspberry TV tuner
Actual configuration is:
RPi3 + hifiberry Digi+ and Raspberry TV tuner
If there is connected only RPi3 and raspberry TV tuner without hifiberry Digi + it is working, but all together I can´t see in TVheadend any tuners.
I think problem is how to switch raspberry TV tuner to second raspberry SPI port (Hifiberry also working over SPI)
My logs:
https://paste.osmc.tv/ehakidogol
Anybody have same configuration?
Thanks for your help
Jan
Hi,
JanSyk did you solve the problem? i am in the same situation with a pi tv hat and a hifiberry digi+ pro.
the hifiberry seems to work fine while the tv hat disappeared from tvheadend.
Anyone does know how to make these two hats working togheter?

tonyfixit
Posts: 3
Joined: Sat Jan 18, 2020 9:14 am

Re: Pi TV Hat questions

Sat Jan 18, 2020 9:38 am

Same problem here. TV hat work with tvHeadEnd when installed on its own, hifiBerry works when installed on its own. When the other is added (I have tried the hifiberry first, then the TV hat and the other way round) In either case the hifiberry either disappears from the audio menu, or is on the menu, but does not work. I have searched the internet and tried the suggested 'solutions; to no avail. Not reloaded tvHeadEnd if the audio failed, so I don't know if the TV hat would still work.

Using PI4, PI TV HAT, official PSU and hifiBerry DAC+.
Buster loaded from official image, and then updated to latest version, but no other changes to software except make it "headless" (/boot/config.txt). Also set VNC, SSH, I2C and SPI active in Configuration.-> Interfaces because, as I understand it, the TV hat uses SPI and the hifiBerry uses I2C.

I have used Kodi and Plex, but these make no difference (this is where the issues showed initially as I used the TV Hat first, then bought the hifiBerry).

So why the conflict? Any ideas out there?

Tony

tonyfixit
Posts: 3
Joined: Sat Jan 18, 2020 9:14 am

Re: Pi TV Hat questions

Sun Jan 19, 2020 3:49 pm

In answer to my own question, I have found that explicitly setting values for the hifiberry and the TV HAT in /boot/config.txt allow the two to work together.
My Pi 4 (1GB) is used headless, so I have included these settings:

Changes in /boot/config.txt
The headless setup (note some are possibly not required as they are from previous experiments):
hdmi_force_hotplug=1
hdmi_mode=68 (to suit my monitor)
hdmi_drive=2

The hifiBerry audio card
dtparam=i2c_arm=on (previously set by Preferences -> Configuration -> Interfaces)
dtoverlay=hifiberry-dacplus, 24db_digital_gain

The TV HAT settings
dtparam=spi=on (previously set by Preferences -> Configuration -> Interfaces)
dtoverlay=rpi-tv

The above information regarding the hifiberry and the TV Hat is derived from the following three locations,
https://www.raspberrypi.org/documentati ... /README.md
Device values in /boot/overlays/README
Options and information see http://rpf.io/configtxt

Notes:
1 - Change hifiberry line (dtoverlay=hifiberry-dacplus, 24db_digital_gain) to suit your own card.
2- The "24db digital gain" parameter is an attenuator, not an amplifier, but it allows a slider bar visible in the desktop volume control.
3 - My audio is fed to my hifi via analogue inputs from the hifi berry. I can view TV video (via VLC) on a monitor, but I could then select HDMI sound from the audio selector of the desktop.
4 - Not installed Kodi or Plex but I see no reason why these should present any problem now the software is explicitly loaded in /boot/config.txt.


/////////////////////////////////////////////////////////////////
/boot/config.txt entries are:
/////////////////////////////////////////////////////////////////
# uncomment if hdmi display is not detected and composite is being output
hdmi_force_hotplug=1

# uncomment to force a specific HDMI mode (this will force VGA)
#hdmi_group=1
hdmi_mode=68

# uncomment to force a HDMI mode rather than DVI. This can make audio work in
# DMT (computer monitor) modes
hdmi_drive=2

# uncomment to increase signal to HDMI, if you have interference, blanking, or
# no display
#config_hdmi_boost=4

# uncomment for composite PAL
#sdtv_mode=2

#uncomment to overclock the arm. 700 MHz is the default.
#arm_freq=800

# Uncomment some or all of these to enable the optional hardware interfaces
dtparam=i2c_arm=on
#dtparam=i2s=on
dtparam=spi=on

# Enable hifiBerry DAC+ and TV HAT
dtoverlay=hifiberry-dacplus, 24db_digital_gain
dtoverlay=rpi-tv

# Enable audio (loads snd_bcm2835)
dtparam=audio=on

[pi4]
# Enable DRM VC4 V3D driver on top of the dispmanx display stack
dtoverlay=vc4-fkms-v3d
max_framebuffers=2

[all]
#dtoverlay=vc4-fkms-v3d
///////////////////////////////////////////////////////////////////////////////////////

Hope this helps

Tony

6by9
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
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Re: Pi TV Hat questions

Mon Jan 20, 2020 9:18 am

tonyfixit wrote:
Sat Jan 18, 2020 9:38 am
So why the conflict? Any ideas out there?
HATs are not intended to be stackable. In particular the EEPROM that is used to automatically load configuration will be at the same I2C address on both cards, and therefore neither will be readable.
As you've found, you can achieve the same thing by manually adding "dtoverlay=foo" lines into /boot/config.txt.
Software Engineer at Raspberry Pi Trading. Views expressed are still personal views.
I'm not interested in doing contracts for bespoke functionality - please don't ask.

User avatar
rpdom
Posts: 16095
Joined: Sun May 06, 2012 5:17 am
Location: Chelmsford, Essex, UK

Re: Pi TV Hat questions

Mon Jan 20, 2020 9:31 am

6by9 wrote:
Mon Jan 20, 2020 9:18 am
tonyfixit wrote:
Sat Jan 18, 2020 9:38 am
So why the conflict? Any ideas out there?
HATs are not intended to be stackable. In particular the EEPROM that is used to automatically load configuration will be at the same I2C address on both cards, and therefore neither will be readable.
As you've found, you can achieve the same thing by manually adding "dtoverlay=foo" lines into /boot/config.txt.
Other than the PoE HAT which uses a different EEPROM address to other HATs, so you can have one PoE HAT and one other HAT on a Pi. That is the only (current) exception to the rule.

tonyfixit
Posts: 3
Joined: Sat Jan 18, 2020 9:14 am

Re: Pi TV Hat questions

Mon Jan 20, 2020 11:28 am

Thanks for the reply. The lack of stacking is not made clear (to me, anyway) and I am used to the Arduino approach, so I had preconveived notions anyway. I sort of wondered about the stacking because of the way the connectorss are arranged. I assumed the eeprom held more than one 'value' or a separable board identity (ie each board has its own eeprom space within the eeprom) and so can can cope with more than one HAT. But, having spent my money, I was going to get my value from them...
Regards

Tony

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