Southpark:
Hi folks!.....at the moment, still trying to figure out why arduino/nrf24L01+ sending to a computer (fitted with usb ch340T/nrf24L01+) only receives 13 text characters (and the rest of the characters go missing). ie.... the arduino side transmits correctly, while the PC side (with the usb ch340T/nrf) only gets 13 of the characters.
The following picture shows this truncation thing that's happening :
arduino/nrf (transmitter) to usb ch340T/nrf (receiver) :
Could certainly get by with sending a maximum of 13 bytes at a time from arduino/nrf24L01+ to computer/ch340T-NRF24L01+. But would be nicer if the reason for truncation can be explained and fixable (if possible).For other test cases (mentioned below), the incoming message gets received with no problem (ie. no truncations) such as.......
- usb ch340T/nrf (transmitter) to arduino/nrf (receiver)
- arduino/nrf (transmitter) to arduino/nrf (receiver)
- usb ch340T/nrf (transmitter) to usb ch340T/nrf (receiver)
The following screenshots are examples of the above 3 cases, where receiving is no problem. ie. no truncation of incoming message.
usb ch340T/nrf (transmitter) to arduino/nrf (receiver) :
Here, a USB ch340T/nrf at the computer transmits text to the arduino/nrf. The text is correctly received. Interestingly, in Termite serial monitor, the very first received incoming byte is equal to the 'number of bytes' received. Not sure why this byte is present. It may be a feature of Termite serial monitor - but....on the other hand, this only occurs when monitoring ARDUINO/nrf RECEIVED (decoded) data while the transmitter is a ch340T/nrf module (fitted to a computer). Also, that first byte (equal to number of received bytes) doesn't show up in Arduino Sketch serial monitor, and also doesn't show up in PuttY serial monitor. So not sure what's going on here yet.arduino/nrf (transmitter) to arduino/nrf (receiver) :
NOTE UPDATE: I noticed that the very last character 'e' was not actually received, which is supposed to be the 31st text character. This seems to be due to a hex 0E and a hex 02 character appearing as the first two received characters. So somewhere, along the line, a hex 0E and a hex 02 got injected into the front end of my text data. Those two characters would then leave room for thirty (ie. 30) text characters (since NRF24L01+ transmits a max of 32 bytes at a time). So the presence of the non-text characters, 0E and 02 would mean no room for the 31st 'e' character. Hence my 'e' character got cut off.
usb ch340T/nrf (transmitter) to usb ch340T/nrf (receiver) :
This involves straight computer-to-computer communications with USB ch340/nrf dongles on both sides (ie. no arduino involved).
A quick summary about what is found so far........the computer with the USB ch340T/nrf24L01+ 'dongle' can certainly send up to 30 text characters at a time to the arduino. But it appears that - at the moment - the Arduino/nrf24L01+ combination can only send up to about 13 text characters at a time to the computer - due to the observed truncation behaviour on the computer (ch340T/nrf) side. Sending 13 bytes at a time to the computer is quite ok in many cases. If somehow we can overcome that limitation, then it would be most excellent.
hey southpark, thanks a lov for vhe arduino code that you have attached, can you please give the other part of the code i.e. the python one which is controlling the other side.
thanks in advance.
our help will be very valuable for my project