Raspberry Pi Forum - Recent Threads

Raspberry with vertical TV - how to rotate

ramzam82 — Wed, 06 May 2026 13:00:04 GMT

Hi all we just connected a Raspberry Pi to a TV which is turned on its side, in a vertical/portrait orientation.

Can anyone advise how we can do it as quickly as possible please?

Its connected via HDMI

Thanks

RE: Raspberry with vertical TV - how to rotate

beacon_dave — Thu, 07 May 2026 19:45:46 GMT

display_rotate looks deprecated:

https://www.raspberrypi.com/documentation/computers/legacy_config_txt.html#display_hdmi_rotate

https://www.raspberrypi.com/documentation/computers/configuration.html#display-settings

RE: Raspberry with vertical TV - how to rotate

kmikemoo — Thu, 07 May 2026 18:54:50 GMT

colporteur You are right. I tried it on my Pi400 and nothing happened on reboot. Maybe that was why the OP asked the question. I editted my original response.

RE: Raspberry with vertical TV - how to rotate

colporteur — Wed, 06 May 2026 23:17:29 GMT

The fix may worked based on context. When I had to do this, it was depended on Raspberry Pi OS version. I also recall hardware version had something to do with it being successful.

I have no Pi's to try it but figured I'd add my context input.

RE: Raspberry with vertical TV - how to rotate

battlecoder — Wed, 06 May 2026 20:47:48 GMT

+1 to this. I'm pretty sure this is how I did it for a project that required a rotated screen. Just to add to this, =1 is a 90 degree rotation, =2 would be 180, and =3 would be 270.

RE: Raspberry with vertical TV - how to rotate

kmikemoo — Wed, 06 May 2026 18:48:25 GMT

EDIT 2026-05-07: colporteur is right. It depends on the version of the Pi. This is why cstanton asked. I only tried it on my Pi3.

Welcome to playing with the Raspberry Pi. This worked on my Pi3.

Open a Terminal Window. That's the black square in the upper left -ish area of your screen. For you... you may have to lean left or right for a bit for decent orientation, but this is a quick fix.

In the terminal window...
sudo nano /boot/config.txt
Add display_rotate=1 to the bottom of the file
Press Ctrl+X, Press Y, Press Enter sudo reboot

Good luck.

RE: Raspberry with vertical TV - how to rotate

cstanton — Wed, 06 May 2026 13:51:25 GMT

Hey ramzam82 ,

Are you running Raspberry Pi OS on the Raspberry Pi?

RE: Trying the Pi Pico RX SDR Project

scottiebabe — Mon, 13 Apr 2026 23:56:46 GMT

Spent some time putting the UI bits on a front panel. Most of the configuration options are only available via the physical UI, not the usb serial interface.

The author did a nice job on the UI, it looks sharp.

Trying the Pi Pico RX SDR Project

scottiebabe — Thu, 09 Apr 2026 14:17:27 GMT

The element14 community (shabaz) pointed me to a very neat SDR project using a RPI Pico.

I have a RPI Pico and lots of generic and jellybean electronic components.

So, I will have a go at building a copy of the open source project.

All of the projects schematics and documentation are available here:

https://101-things.readthedocs.io/en/latest/radio_receiver.html

I don’t have all the exact components used in the project.

I made the following substitutions with similar components I had on hand

The frontend low rdson analog multiplexer was replaced with a 74HC066 quad analog switch (plus a one hot decoder).

I also lowered the gain of the op-amp difference amplifiers.

On power up, the picorx software defaults to an LO frequency of 1.4085 MHz.

I used my signal generator to apply a 150 mVpp carrier with a frequency that sweeps from 10 kHz below the pico’s LO to 10 kHz above the pico’s LO.

I get wonderful sinewaves on the output I/Q channels:

The quadrature detector has significantly more bandwidth than I expected.

You will notice that for frequencies above the local oscillator the Q signal leads the I signal (and vice versa for frequencies below the LO).

The QSD’s response within 1 kHz of the LO is being partially rejected by the AC-coupled difference amplifiers.

The amplitude response of the I/Q channels is not very well matched (I will have to think about that for a bit)

More to experiment with, but impressive results for the simplicity of the project.

RE: Trying the Pi Pico RX SDR Project

shabaz — Sat, 11 Apr 2026 21:59:02 GMT

Nice results! There may be noticeable difference with the various substitutions, because of the higher switch resistance (and I don't know how matched they are, although they should be near-identical since they are all on the same chip), plus the load on the sampling capacitors is different for the different inputs of the op-amp (but then again, it was different for the original circuit too). I guess it would be nicer to also have a quad op-amp serving as a same-load buffer for each sampling capacitor, but maybe the effect is negligible (I've not seen any circuits have any buffers either admittedly).

Regarding the switches, In the past I tried a SD5400CY, perhaps the 3253 is better (it's seen a lot in online circuits, whereas the SD5400 is rarely seen) simply because I thought there was less inside to be mismatched or cause any other switching noise from all the additional MOSFETs in the silicon in the 3253), but I've never compared. SD5400CY is harder to find and too pricey now (in the past it was very cheap) so those are negatives too.

RE: Trying the Pi Pico RX SDR Project

scottiebabe — Fri, 10 Apr 2026 15:19:43 GMT

Here is a spot test of the image rejection performance at 1.4 MHz

First I apply an AM RF signal 6 kHz above the LO

Signal Generator:

The recorded I,Q samples from the o-scope

The magnitude of the complex signal I + jQ

The FFT of the I,Q samples

There is a DC offset in the I,Q samples so some power will be seen at 0 Hz. An image of the + 6 kHz signal exists but is attenuated by approximately 30 dB. On a linear scale the image is less noticeable

Adding a unmodulated carrier 8 kHz below the QSD’s LO

The measured I,Q samples

In the frequency domain the -8kHz tone (noisy, relaxation oscillator, not crystal controlled) has an image at +8 kHz, but attenuated by 30 dB

RE: Trying the Pi Pico RX SDR Project

DAB — Thu, 09 Apr 2026 20:27:03 GMT

Very nice build.

RPI Pico2 SDR - First Attempt

scottiebabe — Fri, 03 Apr 2026 13:52:11 GMT

Have been experimenting with implementing an SDR on a RPI Pico 2.

I put together a bare bones SDR for narrowband FM

Diagram created with https://app.diagrams.net/ Source: (remove the .txt extension)/cfs-file/__key/communityserver-discussions-components-files/91/pico2sdr.drawio.txt

The input is IF is oversampled, frequency translated to baseband, filtered, and then decimated by a factor of 3. A polar discriminator demodulates the narrow FM signal and is low-pass filtered and output to an I2S DAC.

As a first test I am applying a narrowband FM signal directly to the ADC input of the pico2

The I2S DAC I used has a class-d BTL output. I had to add an LC filter to the output for the scope to display the audio output and not the class-d pulse train.

A few different input signals and demodulated output shown on my o-scope

When the input is below 10 mVpp the SDR starts to struggle.

The output amplitude is a function of the frequency deviation, not the input amplitude.

Pretty cool.

RE: RPI Pico2 SDR - First Attempt

DAB — Sat, 04 Apr 2026 19:28:32 GMT

Very cool project.

RE: RPI Pico2 SDR - First Attempt

scottiebabe — Sat, 04 Apr 2026 18:24:57 GMT

Thank you so much for the project link!

I believe the author has shared some more details on their personal site

https://101-things.readthedocs.io/en/latest/radio_receiver.html

I will definitely have to try it out once I find some low rdson quad switches

I wanted to avoid the complexities of IQ sampling so its easier to tune in VHF. There may be tuner ic's with IQ outputs. I am trying to just start simple.

RE: RPI Pico2 SDR - First Attempt

scottiebabe — Sat, 04 Apr 2026 17:19:48 GMT

Tuning to 462 MHz

I tuned my LO such that my FRS radio was down converted to a low IF

I have a T5725 from years ago.

Pressing the paging/call tone button

community.element14.com/.../frspaging.mp3

Unfortunately the local weather radio station officially went off the air April 1, otherwise I would tune to that.

RE: RPI Pico2 SDR - First Attempt

dang74 — Sat, 04 Apr 2026 12:25:23 GMT

Thanks shabaz I was pretty sure that was the case... just needed assurance.

RE: RPI Pico2 SDR - First Attempt

shabaz — Sat, 04 Apr 2026 11:41:18 GMT

A friend pointed me to this project recently:

https://github.com/dawsonjon/PicoRX

However there's no nice flow chart so it's not easy to follow (I didn't get time to peek at the source code yet).

Hardware-wise it's very cut-down, they are trying to do everything in the Pico, whereas personally I would have used I2S DAC too, and maybe Si5351 or some other external freq synth.

Looking at the schematic, they went with zero-IF it seems, since they generate IQ externally to the Pico. I didn't think that would work, but I guess the Pico ADC is fast enough to sample both close enough. I think they are using Pico and not Pico 2 so that must be impacting performance (just speculating, I have not tried that project).

For 90 deg oscillator output I don't know if say Si5351 can be programmed to do that, it would then be a useful freq synth for zero IF. For a PC-based SDR project I used D-type flip-flops to generate quadrature from a single clock, but that's limiting, since it won't operate at the high speeds for say 144MHz Rx. But personally I think low-IF is the way to go when there's only one ADC in the pico.

RE: RPI Pico2 SDR - First Attempt

shabaz — Fri, 03 Apr 2026 22:18:01 GMT

I don't want to pre-empt the actual answer, but generally, yes : ) once it's been ADC'd, all the math can happen internally in code.

RE: RPI Pico2 SDR - First Attempt

robogary — Fri, 03 Apr 2026 19:12:51 GMT

nice

RE: RPI Pico2 SDR - First Attempt

dang74 — Fri, 03 Apr 2026 15:27:50 GMT

Impressive. Just so I am on the right track, the blocks depicted within the dotted lines and labeled "RPI Pico2 Software Defined" are all implemented as code being run on the Pico2?

RE: RPI Pico2 SDR - First Attempt

scottiebabe — Fri, 03 Apr 2026 15:10:14 GMT

That is awesome! Thank you for sharing, my google has struggled to turn up sdr projects. I will have to borrow some ideas. Neat that the psoc has hardware accelerated digital filters. On the Pico2 the floating point co-processor has a multiply accumulate instruction (VFMA) and a divide instruction, otherwise it would be a struggle

RE: RPI Pico2 SDR - First Attempt

gpolder — Fri, 03 Apr 2026 14:09:25 GMT

Cool!, couple of years ago I didi this with a PSOC (https://www.agri-vision.nl/portal/projects/5-software-defined-radio-with-psoc) and somewhat later with a Teensy, for the latter I needed a codec to get the audio into the Teensy.

I am having trouble with my Pi-Desktop computer kit SATA bridge

LesRhorer — Wed, 04 Dec 2024 10:03:45 GMT

I have a Pi-Desktop case with the SATA bridge, and it no longer sees the /dev/sda target. I am unsure if it is a bad SSD or a bad bridge. I don't have another mSATA slot to check it. I have poked around, but I can't find a likely piece of hardware that would seem to be the bridge. I have tried lsusb, lshw, etc. Is there away I can inspect the bridge to see if it is operating?

RE: I am having trouble with my Pi-Desktop computer kit SATA bridge

rip — Sun, 15 Mar 2026 22:23:16 GMT

Will try again

Thanks for your help