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by RPI_333333
Tue Mar 19, 2019 6:57 am
Forum: Camera board
Topic: Jpeg compression On board or on RPI
Replies: 4
Views: 196

Re: Jpeg compression On board or on RPI

Thanks for the answers- I'ts all clear now :)
by RPI_333333
Sun Mar 17, 2019 9:48 am
Forum: Camera board
Topic: Jpeg compression On board or on RPI
Replies: 4
Views: 196

Jpeg compression On board or on RPI

Hello, I would like to know if the camera compression (to Jpeg) is done on the camera board itself or on the Raspberry Pi. More detailed, I would like to know if the raw image is transfers to the Raspberry pi (Via the CSI interface) or the compressed image in order to understand better the data rate...
by RPI_333333
Mon Dec 10, 2018 6:37 am
Forum: Python
Topic: Best Python IDLE for RPI
Replies: 0
Views: 132

Best Python IDLE for RPI

Hi I write my python code on RPI 3 using Thonny. I couldn't find how to fold parts of the code (for example to fold fuction so i can see only the declaration). Does anyone know how to do that on Thonny? Maybe i should use a different program, what is the best program to write python code on RPI ? I'...
by RPI_333333
Sun Dec 09, 2018 5:38 am
Forum: Python
Topic: Using SPI on python
Replies: 18
Views: 1341

Re: Using SPI on python

The pigs version (like the working C program) bypasses the Linux SPI driver. So the SPI hardware is okay and the wiring is correct. This suggest the Linux SPI driver is corrupted or misconfigured. I'd be tempted to write a new image to the SD card. I re-installed the RPI software and now it works! ...
by RPI_333333
Wed Dec 05, 2018 2:02 pm
Forum: Python
Topic: Using SPI on python
Replies: 18
Views: 1341

Re: Using SPI on python

joan wrote:
Wed Dec 05, 2018 1:45 pm
That's unfortunate. I would have expected the same return values as you got from your first C program (255 255 48 17).
Oh !
sorry, i mistyped...

The result is indeed what you expected !

Code: Select all

pigs spix 0 0x40 0 0 0
Result: 4 255 255 48 17


So what can we learn from that ?
by RPI_333333
Wed Dec 05, 2018 12:34 pm
Forum: Python
Topic: Using SPI on python
Replies: 18
Views: 1341

Re: Using SPI on python

Let's just confirm the wiring is correct. Start the pigpio daemon if it isn't running. sudo pigpiod Get a handle to SPI 0.0 pigs spio 0 50000 0 That should return handle 0. Transfer 4 bytes to handle 0. pigs spix 0 0x40 0 0 0 That should return 4 (the number of bytes transferred) followed by the re...
by RPI_333333
Wed Dec 05, 2018 9:06 am
Forum: Python
Topic: Using SPI on python
Replies: 18
Views: 1341

Re: Using SPI on python

joan wrote:
Wed Dec 05, 2018 8:53 am
Are you a member of group spi?

groups

will list your groups.

If you do not see spi enter the command

sudo adduser pi spi

You will need to logout and log back in for a group change to take effect.
I checked- i am a member in spi group

Any other ideas ?
please help guys...
by RPI_333333
Wed Dec 05, 2018 6:48 am
Forum: Python
Topic: Using SPI on python
Replies: 18
Views: 1341

Re: Using SPI on python

the bcm2835 library uses direct access to the hardware. Maybe you have something wrong with the device driver. What is your /boot/config.txt ? whats is the result of ls -l /dev/spi* ? Which version of python are you using ? (python2 or python3) Did it fail on both python Maybe try this version of C...
by RPI_333333
Tue Dec 04, 2018 12:53 pm
Forum: Python
Topic: Using SPI on python
Replies: 18
Views: 1341

Re: Using SPI on python

It looks like it should work to me. I ran your Python code (changing the SPI speed to 50000 to make sure it could be captured by piscope). Screenshot from 2018-12-04 12-18-11.png Maybe something is not installed correctly at my end ? Could you explain how should i check? when i run lsmod i get: lsm...
by RPI_333333
Tue Dec 04, 2018 11:17 am
Forum: Python
Topic: Using SPI on python
Replies: 18
Views: 1341

Re: Using SPI on python

I would run (my) piscope and compare what is going on with the C and the Python. That should make the difference (and hopefully the error) obvious. http://abyz.me.uk/rpi/pigpio/piscope.html (requires the pigpio daemon to be running, sudo pigpiod ) I tested both codes with piscope. It seems that whe...
by RPI_333333
Tue Dec 04, 2018 7:19 am
Forum: Python
Topic: Using SPI on python
Replies: 18
Views: 1341

Re: Using SPI on python

What is your device and could you also put your C code also. We need to compare what you did. Thank you for your answer, The device is an FPGA development board which i want to connect to my RPI3 via SPI. I am trying to read one of the FPGA registers. The goal: Reading FPGA register at address 0x40...
by RPI_333333
Mon Dec 03, 2018 1:27 pm
Forum: Python
Topic: Using SPI on python
Replies: 18
Views: 1341

Using SPI on python

Hi I have an SPI device that connected to my RPI 3 via SPI. I installed and enabled SPI. I have a sample code to test the connection between the RPI to the device and it worked fine. The code read the value of register at address 0x4000 and print it. The code is in C and uses wiring pi libary and BC...
by RPI_333333
Thu Nov 15, 2018 6:12 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: RPI 3 UART max speed
Replies: 4
Views: 1380

Re: RPI 3 UART max speed

Thanks you all for the answer,
I still don't understand:
If the PL011 UART can go up to 3Mbit/sec why the PL011 spec mentioned 921600 bps ? what am i missing?
by RPI_333333
Wed Nov 14, 2018 1:35 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: RPI 3 UART max speed
Replies: 4
Views: 1380

Re: RPI 3 UART max speed

The RPi has 2 UARTs, a PL011 and a "mini UART". In general it's best to use the PL011. The PL011 uses the ~48MHz uart clock as a base, which results in a maximum achievable baudrate of 3Mbit/sec (48MHz/16). I recently did some tests and transmitting data at 3mbit/sec looked fine on the scope. I hav...
by RPI_333333
Wed Nov 14, 2018 9:06 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: RPI 3 UART max speed
Replies: 4
Views: 1380

RPI 3 UART max speed

Hi, I saw many posts on this issue but still don't have a clear answer. I would like to use the UART on the Pi3 at the highest rate possible but still make sure the transmission is fully realiable. I haven't managed to find a clear answer: what is the maximum UART rate for realiable transmission ? I...

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