Dear Dialog,
I'd like to know following points about DA14580's central operation mode.
Q1: We observed that rssi seems to have strong dependancy to the scanning channel. When we set 5seconds
for scan interval, we saw 5 seconds'periodic change of rssi by almost 10 - 15dBm change even the distance
在屏蔽室内进行了实验。
Can you explain this phenomenon?
We have checked there is only a very slight varience like 1dBm for peripheral's transmit power.
Q2: Is there any method available which allows us to retrieve the channel number information by each adv
收到数据包？
Q3: Can we make DA14580 scan by only one channel? I mean no frequency hopping between ch.37, 38 and 39.
致以最诚挚的问候，
Keywords:
Device:
Hi yterasaki,
Q1. A badly matched antenna would show this effect and should be checked easily by measuring the transmited power of this antenna over all channels. You mention that you use a 5 seconds scan interval, does this mean that you are reading the RSSI of one connection over 5 seconds or you receive on other channels as well and having those RSSI values read out to? You read the peak hold or the average RSSI value ?
问题2。不幸的是，应用程序无法查看他在哪个频道上获得了广告事件。这在蓝牙协议栈代码中有很深的体现。
Q3. Normally the three advertising channels are scanned in order to avoid interfierence from other devices that trasmit at that time. There is no way to scan
indivividual advertising channels
Thanks MT_dialog
Thanks, Dialog staff,
I'll check out anntena charactersitc, but regarding the question about rssi is either average or peak holded,
I've traced FW, but it seems that rssi value is retrieved by kernel function and I cannot find if the
平均值或峰值保持。我使用的是prox\u monitor\u ext的Dialog原始源代码，如下所示。
DA1458x_SDK\5.0.3\projects\target_apps\ble_examples\prox_monitor_ext\Keil_5
Please tell me which mode original reference is using for rssi value.
致以最诚挚的问候，
Regarding Q3:
Please add the option to scan individual channel (or any other combination of channels 37-39) as a feature request.
This is highly important for many applications and most of your competitors have this option.
Hi yterasaki,
如果我理解正确，您使用接近监视器应用程序并检查gapm\u adv\u report\u ind struct中指示的播发字符串的rssi值，是否正确？如果是这种情况，那么您正在测量的rssi是当前广告字符串的当前rssi，而不是平均值。你能澄清一下你是如何测量RSSI的吗。
Thanks MT_dialog
Dear Dialog,
Thanks for your comment. Our measuring condition is 1pcs DA14580 based peropheral and 1pcs DA14580 based
central. Advertise interval is 100mS and scan interval is 5seconds.
We will re-measure rssi with the ideal condition and if we still have problem, I'll report it in this mail.
About rssi value, I understand that current my measuting is not averaged, namely peak hold. Could you tell me
where in the proximity monitor code we should change to retrive rssi as averaged value?
致以最诚挚的问候，
Hi yterasaki,
One more question regarding your measurements, i am trying to understand the method of measuring the rssi in different channels with the proximity monitor, since in every scan window you can receive only from one advertising chanel, when the first advertising windows finishes the scanning on one channel, and the values are displayed on the console, when its time for the second window you see those values changed and differ between 10 - 15dbm ? Can you please clarify your way of measuring ?
Thanks MT_dialog
Hi Dialog,
测量是通过每个1分的个人电脑arl and peripheral device. All the advertising data captured by the centaral is
transferred to the server with time stamp. Please take a look at the attached image. You can see the rssi value has periodic
change by almost 5.5 seconds which corresponds to the scan interval of central. During the measurement, both of central
and peripheral devicesa are fixed, no move.
please tell me how to change the FW source to get averaged rssi value.
致以最诚挚的问候，
Hi yterasaki,
Sorry for the mis-understanding, since you refer to the RSSI of the advertising packets, the available RSSI is aquired by the stack (via ROM code) and passed to the advertising indication event, there is no implementation in order to get anything else besides the returned value. The value is the current value of the advertising packet. Also in an attemp to try and replicate your problem on my setup seems that the rssi between two succesive channels doesn't have a difference more than 1 db when using a development kit and a dongle with proximity monitor application.
Thanks MT_dialog
Dear Dialog, Thanks, I understood fully.
致以最诚挚的问候，