topic End device does't receive direct data from coordinator in 8-bit Microcontrollers

End device does't receive direct data from coordinator

Solus — Mon, 17 Nov 2008 16:59:54 GMT

Hi,
unfortunately I do not get ahead and I need your assistance. I can establish a 802.15.4 connection between Coordinator (CO) and End-Device (ED). The datatransfer from ED--> CO is working well. As a response of this data frame I would like immediately send back a data telegram from CO--> ED.
The problem is the ED does never receive the paket. Why not?
If I run the communication with beacons and in indirect mode, it works.
Attached you can see the daintree trace of the establishment of the communication and the first data transfer from ED-->CO. Why does the communication from CO-->ED not work?

Any ideas?

Thanks for any help

081117_DirectDataTransmissionFailed1.jpg

Message Edited by t.dowe on 2009-10-27 12:02 PM

Re: End device does't receive direct data from coordinator

Solus — Mon, 17 Nov 2008 19:42:36 GMT

I found the problem :smileyhappy:
I have to set the mlmeRxEnableReq_tag request on the end device. This means I have to switch on the receiver for a period.
But I'm a little bit confused about the structure

typedef struct mlmeRxEnableReq_tag {
bool_t deferPermit;
uint8_t rxOnTime[3];
uint8_t rxOnDuration[3];
} mlmeRxEnableReq_t;

What does deferPermit, rxOnTime[3] and rxOnDuration[3] exactly mean? I can't find any documentation about this!

Thanks for any help.

Re: End device does't receive direct data from coordinator

addiyi — Tue, 18 Nov 2008 17:41:10 GMT

Hello,

deferPermit - TRUE if the receiver enable can be deferred until during the next superframe if the requested time has already passed. FALSE if the receiver enable is only to be attempted in the current superframe. This
parameter is ignored for nonbeacon-enabled PANs.

RxOnTime - The number of symbols from the start of the superframe before the receiver is to be enabled. The precision of this value is a minimum of 20 bits, with the lowest 4 bits being the least significant. This parameter is ignored for nonbeacon-enabled PANs.

RxOnDuration - The number of symbols for which the receiver is to be enabled.

Regards,
Adrian