duplicate and dropped packets on uart characteristic

RE: duplicate and dropped packets on uart characteristic

Hung Bui — Wed, 12 Aug 2015 10:19:03 GMT

@robotjosh: I reproduced the issue here. I have reported it internally. It will be fixed in the future release of the nRFToolbox.

RE: duplicate and dropped packets on uart characteristic

robotjosh — Fri, 07 Aug 2015 05:34:06 GMT

This same test code run on the "nRF UART" ios project correctly receives all packets at 4kb/s. Something is wrong with the nrf toolbox ios project.

RE: duplicate and dropped packets on uart characteristic

Hung Bui — Wed, 05 Aug 2015 10:44:47 GMT

@robotjosh: Testing your code here didn't show the issue. I was not able to recompile the nRFToolbox app because I don't have the iOS app development environment. I tested using Master Control panel tool on PC. And didn't see any duplicate or dropped packet.

However, there is one bug in your code may cause the bp pointer goes out of bound is the condition "while(bytesleft > 0)". bytesleft is unsigned int, so it will not be negative at the end of the loop but go overflow and keep the loop going.

Note that the sniffer also work with the PCA10028 DK, so if you have 2 kits you should be able to use the sniffer.

RE: duplicate and dropped packets on uart characteristic

robotjosh — Wed, 05 Aug 2015 03:34:00 GMT

I don't have the hardware to do a sniffer trace, but here is my ble file transfer demo made from the keil ble uart demo for the nrf514 dev kit. file transfer demo code This code functions the same as the example but on receiving "Play" it sends over ble uint32_t values sequentially from 1 to 4096. The IOS demo code is created from the IOS-nRF-Toolbox-master with the only changed file being UARTViewController.m This file sets a ble_state var to 1 an initializes a uint32_t buffer for receiving the test data. Then it fills up that buffer with the test data and prints the results. For me, transfer speed is 4kb/s but each data slot is either correct or it is overwritten with a value that should come a little later with many slots duplicated.

RE: duplicate and dropped packets on uart characteristic

Hung Bui — Tue, 04 Aug 2015 14:30:29 GMT

@robotjosh: If possible please also attach a sniffer trace.

RE: duplicate and dropped packets on uart characteristic

robotjosh — Tue, 04 Aug 2015 12:26:58 GMT

Testing this on ios nrf toolbox uart example. I'll reduce the project down to a demo of this file transfer part and post it tonight.

RE: duplicate and dropped packets on uart characteristic

Hung Bui — Tue, 04 Aug 2015 12:19:55 GMT

@robotjosh: BLE based on reliable protocol so there should be no duplicate or missing packet, by theory. I don't see any issue with the code you posted. Could you send the whole project so that we can test here ? With which central did you test with ?

RE: duplicate and dropped packets on uart characteristic

Alex — Tue, 04 Aug 2015 07:43:58 GMT

Another problem can be your host device. When we first tried BLE on Windows 8 tablet and tried to use W8 drivers with Delphi we had lost and duplicate packets. Then switched to Bluegiga dongle with native Bluegiga drivers

RE: duplicate and dropped packets on uart characteristic

Alex — Mon, 03 Aug 2015 12:19:59 GMT

I do

do{
  err_code = ble_hrs_heart_rate_measurement_send(&m_hrs, packets, 0);
}while(err_code == BLE_ERROR_NO_TX_BUFFERS);