nrf24l01 | nRF24L01 library for C51

1. Summarize the Problem:

I wrote a userspace SPI driver in linux for the NRF24L01+ transceiver. My goal is to send files to a server. A jetson nano is the sender, and a raspberry pi 3b+ the receiver. Both the spi and nano are running Linux.

I can consistently send packets and receive acknowledgements.

However, the issue is whenever I send a packet such as 0x ff ee dd 00 cc bb aa the receiver only receives the packet 0x ff ee dd 00 00 00 00. So what is happening is that whenever the first byte encountered is zero, the rest of the packet becomes zero. This causes the files I send to become corrupted.

I was able to reproduce this bug with a char array having a similar pattern. I noticed this trend when I printed out the file contents I was sending on the transmitter and receiver.

1. What I've tried:

I've tried altering my SPI read function. What I thought was happening was the chip select line was being flipped high early. This did not work, I got the same results.

I've printed the packets before calling the ioctl() function from the transmitter and the packet remains intact.

I've printed the return value of the ioctl() function to see how many bytes I was receiving and sending. I was sending 31 bytes from the transmitter, and receiving 32 bytes from the receiver. So it doesn't look like my reads and sends are failing.

If I had a logic analyzer my next step would be to check the SPI pins on the transmitter, but unfortunately I don't have one.

I've added a 10uF decoupling capacitor on the transceivers and that sped up communication.

1. Show Some Code:

Receiver side:

I use a NRF24L01 Module to communicate with 2 arduino..

I send this:

I am reading the data from a "Torque Wrench" using "USB Host Shield2.0" and Arduino UNO. I am receiving correct data from my "Torque Wrench" Data is receiving in a array. But when I started reading data after "for" loop inside Void loop() I am receiving incorrect data. I attached Both output pictures correct and incorrect data.

Basically I am read data from Torque Wrench and send to receiver using Nrf24l01. I am receiving incorrect data.

My question is :- Why I am reading Incorrect data outside "for" loop.

1. Correct Data inside "for" loop :- enter image description here
2. Incorrect Data outside "for" loop :- enter image description here

I'm trying to wrap arduino's RF24 functions into a simpler class that I could use more intuitively in the future, so I have made a .h file:

I am attempting to make a simple Vehicle to Vehicle V2V commutation system using one nRF24L01 as a transmitter and another one for a receiver connected to Arduino Uno. Then I connected 2 GPS devices for each Arduino board type Adafruit Ultimate GPS Breakout Version 3. Is there a mathematical equation or a simple code that can be used to deal with the longitude and latitude obtained from the two devices to know the distance between the two vehicles as well as determine the direction, for example, cars approaching or moving away from depending on the updated values sent from the sender.

I tried to calculate the distance within the coverage area provided by nRF24L01 which provide 500 meters, for example, a straight road with 2 vehicles when the 1st vehicle enter the range of the 2nd vehicle I can get the approximation distances in real time between these vehicles by taking the advantages for the GPS located in both vehicles. Actually I read about different methods but I looking for something simple since I try to apply it in my simple suggested scenario and I successfully transmitted the longitude and latitude of the 2nd vehicle over the nRF24L01 to the 1st vehicle

below the data that I got when I connect my GPS to Arduino

I am using float switches(3 Nos) as depicted below and a NodeMCU esp8266,

all three switches have been defined in the same way(input_pullup)

2 of these switches change state as the switch movement commands but one of these switches are not changing state and are stuck in LOW forever

please find the pin and code attached below with a picture of the switch in open and closed state.

I need to execute several commands in the background with Tkinter repetedly but mainloop() does not allow me to use while.true. If I use While true with the mainloop in the end, the code in while true is executed only once.

So I found this solution. I moved all the content inside while true to a function called "sinyal" and then I used .after to call that function as it was written there. Now some of my code is executed repeatedly as I want (like receiving data from arduino repetedly) but I lost all my canvasses and thus images. I cannot see any images drawn on the screen.

btw this is a weather station project on raspberry pi. Pi receives weather data from arduino via radio transmission, parses data, shows it on labels and shows certain images on the screen based on said data (gauges).

Right now all I can see is black background and labels with the values in them. None of the images I want to be drawn is there. What could be the reason of this?

Code: