tomojitakasu/pocketsdr

pocketsdr's Issues

The tracking loop can be locked only for 4s

Dear tomojitakasu,

I am writing to discuss an issue we encountered while working on this project.

Firstly, we would like to express our gratitude for the amazing open source project you have provided. We followed the project guidelines and successfully created the PCB. Additionally, we completed the driver installation and all the required configurations.

Afterwards, we proceeded to capture the signal for a duration of 100 seconds and performed tests using the pocket_acq.py and pocket_trk.py scripts. The signal acq process did not encounter any problems. However, when testing with pocket_trk.py, we noticed that the tracking loop only remained locked for the initial 4 seconds of every 10-second interval. Interestingly, when using simulated signal testing, the lock was maintained continuously.

We are reaching out to seek your expertise in understanding the underlying cause of this issue and to inquire about potential solutions. We apologize for any inconvenience caused and genuinely appreciate any assistance you can provide.

Thank you for your time and consideration. We eagerly await your response.

Best regards

is 2-bit max2769b array elemnts enought for anti jamming

I was reading the future works of pocket-sdr. I would like to know whether 2-bit adc arrays is adequate for antijamming mitigation?

Default Register Settings on MAX2771

Hi, I am trying to folow the MAX2771 datasheet and they say right at the beggining of the "Detailed Description" chapter on page 17 that certain values must be programmed into the register 0x00 and 0x09. I have noticed that the pocket_conf app omits this. I am not sure how important is it ( MAXIM has not answered yet) but since they say that it must be done whenever the IC is power-cycled it seems important. Hence I have created the default hexadecimal .conf file reflecting this requirement and programmed the ICs. After reading the register values with pocket_conf -h it is obvious that only register 0x00 was correctly altered. Register 0x09 stayed intact. After examining of the sdr_conf.c file I found out that the register 0x09 is not considered here. Is it possible to look into it since it might have impact on the quality of samples.
Thank you in advance.

Parts selection problem of 3.3V LDO

The part for U5 (3.3V LDO) in HW/pocket_sdr_v.2.1.xlsx is not suitable. The output voltage of the LDO may be 5V instead of 3.3V by the current circuit design.

Replace the part for U5 by the proper one, in which the pin 4 of SOT-23-5 package shall be NC (no connection).

ADC Clock Alignment implementation

I haven't checked the actual PCB layout yet, but based on the current circuit file (pocket_sdr_v2.1_sch.pdf), the ADC clock alignment doesn't seem to be implemented as Maxim intended.

The MAX2771 specifications (19-100378; Rev. 0; 7/18) describe multiple MAX2771s setup in the ADC Clock Alignment section on page 22 as:

One device would be designated as the clock source and configured to output its ADC clock on its CLKOUT pin. This clock signal can then be buffered and distributed through an external clock tree. The buffered clocks are then input on the ADC_CLKIN pins of all MAX2771 devices (including the clock source), and all devices are configured to use this external clock as their ADC clock.

In contrast, the PCB schematic shows that the CLKOUT of U1 MAX2771 is connected only to U2 MAX2771, not to itself. Instead, its own ADC_CLKIN is pulled to ground.

please open source snap positioning hardware

it is seemed that snapshot positioning module designed with (STM32L4+MAX2769B). and it's data could be post-processed by pocket-sdr. it would be great if you include it here in pocket-sdr repo and make it open source.

Amazing!

This looks amazing, great work! Is there a way to purchase one of the SDR boards? Don

The isolation resistor for the RF_DIVIDER is missing.

The RF_DIVIDER "PD0922J5050S2HF" requires an external 100 Ohm resistor that is called isolation resistor between two output ports, but that is missing in the circuit.
This issue degrades isolation between the two ports. For example, the reflected signal from LNA-L port interferes with the signal to the LNA-H port.
However, it is not so serious because the return loss on both ports of the MAX2771 is not so high.

Real-time Signal tracking with pocket_trk cannot used in Ubuntu 22.04.3 LTS

Dear tomojitakasu,

We tried the PocketSDR with the real-time signal feature, but seems like pocket_trk -r is not a valid argument when we try it, which is weird. Wonder if there are any solutions for this?

Best Regards

Extending the code to decode Beidou B2b signal

Dear tomojitakasu,

Thanks for sharing the amazing work!
I have learned a lot of basic SDR knowledges from PocketSDR, and the code is really compact.

Currently, I want to extend the code to decode Beidou B2b signal.
However, I encountered some problems because the LDPC library can only decode binary LDPC code.
The Beidou B2b needs non-binary LDPC decoding.
According to the ICD, the Extended Min-Sum Method or Fixed Path Decoding Method may required to decode the navigation message.
Is it possible to decode the message with other method or using existing libraries?

Thank you very much! Looking forward to your reply.

Best regards.