How may I set a low, middle and high frequency channel [0; 78] of the ISM 2.4GHz band?? The Bluetooth modules I have in mind are HC-06 or HM12 and similar. It is a crucial task to perform during a laboratory test under the rules of EN ETSI 300 328 radio standard.
Regular AT commands do not provide that option for any 2.1 EDR modules or 4.0 and newer [BLE]. Unfortunately, the modules are working constantly with adaptive frequency hopping.
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Guys i have a little problem. I have 2 csv files, i want to copy some data from one csv to another where id is the same. For this i use vlookupfunction but something is not good.
The orginal string in orginal csv is:
48 Port Managed Layer 3 Gigabit Ethernet Switch with optional 10GigE uplink and 802.3af and Legacy Power over Ethernet. Includes 48 - Copper Gigabit (1000Base-T) access ports and 2 - High Speed Expansion Slots. Provides up to 370 watts of 802.3af compliant power. Features include 802.1Q VLANs, GVRP, 802.1p QoS, 802.1w Rapid Spanning Tree, 802.3ad Link Aggregation, Auto MDI/MDI-X, CLI, HTTP GUI, SSH, SSL, RADIUS, SNMP. 19" Rackmount 1U housing. Includes AC PoE power supply. Supported expansion modules: Dual Stacking XIM (4700470F1, 4700470F2, 4700470F5), Dual SFP XIM (1700473F1), Dual SFP+ XIM (1700471F1).
And when i use this function
=IFERROR(VLOOKUP($A2,osnova.csv!$B$2:$AD$1660,8,0),IF(G2="","",G2))
I get this string:
48 Port Managed Layer 3 Gigabit Ethernet Switch with optional 10GigE uplink and 802.3af and Legacy Power over Ethernet. Includes 48 - Copper Gigabit (1000Base-T) access ports and 2 - High Speed Expansion Slots. Provides up to 370 watts of 802.3af compliant power. Features include 802.1Q VLANs, GVRP, 802.1p QoS, 802.1w Rapid Spanning Tree, 802. 19" Rackmount 1U housing. Includes AC PoE power supply. Supported expansion modules: Dual Stacking XIM (4700470F1, 4700470F2, 4700470F5), Dual SFP XIM (1700473F1), Dual SFP+ XIM (1700471F1).
The difference is that i have in orginal string this part and in the copied version i lose that part:
.3ad Link Aggregation, Auto MDI/MDI-X, CLI, HTTP GUI, SSH, SSL, RADIUS, SNMP.
Can someone help me with this? Did i do something wrong in my function?
Your version of Excel must be hitting the character limit of VLOOKUP. You should not be using this function in the first place, it's broken and it sucks. Consider using much superior INDEX/MATCH combination =index(osnova.csv!$H$1660, match($A2,osnova.csv!$B$2,0)).
Hello Good People of the Internet!
First time asking...
I have a modern PC running Fedora 24 with a real-time patch (CCRMA audio tools) with an ASUS Essence STX II sterio sound card installed on PCIe. With it we run a playback/capture application. Also, we need to integrate CAN and BLE into the system and have a PCIe-card for each of these functions. The CAN PCIe card is from PEAK and the BLE card is an Intel 8260 M2 card that HP have put on a PCIe card (AFAIK).
With only the audio card installed it works fine (using ALSA as API). When the CAN and BLE is installed the following is observed:
Playback works as before.
One capture channel only returns zero (0) or minus one (-1) in all samples.
The other capture channel returns values in the range -2..2 and when applying our application signal processing low quality, but detectable, expected results are presented.
The ALSA API report no problems in setup and configuration.
CAN and BLE functions as expected.
Without any deeper PCIe experience I suspect that CAN and/or BLE PCIe cards jumble the mapping of the sound card functions.
Can someone:
- Tell me if my hunch is in the ballpark?
- Inform me on where I might go for information on how to rectify the problem?
- ...or, share a solution?
Thanks!
I've to design an IO-module for an industrial control system in a CAN-bus network.
The IO-pins (10-40 pins) have to be all multi purpose: digital and analog in- and output. Further the pins have to serve as a communication port when needed: Modbus RTU, modbus TCP, DALI, etc. (Analog input max 7 channels)
I understand that all of this options need different HW; like galvanic isolation or different voltage levels etc.
Costs have to be as low as possible.
I was thinking of making this bit of additional hardware as a plug-in module or as an optional additional sandwich PCB.
My question is: Is an FPGA the right choice for this because of the reconfigurable purpose of the IO-pins? (Xilinx, altera/intel and microsemi have FPGA's with ADC's)
You didn't specify if IOs have to be reconfigurable at compile or runtime. In most cases, you cannot change IO properties (type, voltage, terminations,etc.) once HDL code is compiled into FPGA bitstream.
I am trying to figure out what the maximum throughput of a Bluetooth 2.1 SPP connection is.
I found 2 publications concerned with the topic (1, 2) and they both show diagrams, which show the throughput as a function of the Signal to noise ratio (that I can assume to be perfect for my concideration) and the kind of ACL package used. My problem is, I have no Idea which ACL packets are used. How is this decision made? Is it made on the fly, like "what's needed to transfer the current data is used"?
Furthermore, in the Serial Port Profile specification (chapter 2.3) I found this sentence:
This profile requires support for one-slot packets only. This means that this profile
ensures that data rates up to 128 kbps can be used. Support for higher rates is optional.
The last sentence realy confuses me. How do I find out whether this "option" applies in my case?
This means that in SPP mode, all bluetooth modules should work up to 128kbps, and some modules may work even faster.
Under SPP is RFCOMM, which tries to deliver the packets as quickly as possible. If only one packet is sent in one timeslot, you get the 128kbps. The firmware of the bluetooth module, or the HCI driver however can do things differently.
There are SPP speeds up to 480kbps reported - however this requires that both SPP modules are from the same vendor (e.g. BlueGiga iWrap modules can do this speed).
On the other end, if you're connecting to an unknown device, for example a BT112, or an RN41 module to an Android device, the actual usable SPP bandwidth can be much lower than 128 kbps (I have measurements as low as 10kbps).
In case of some old generation iPhones, the usable SPP bandwidth is around 8 kbps.
It is a wise idea to treat "standards" and "datasheets" very conservative, and do your own measurements if actual net data bandwidth is critical.
Even though BT, BT+EDR has theoretical on-the-air bitrates of 3Mbps, the actual usable net data bandwidth is a way smaller.
I have an application concept that required real-time audio signal processing that can be broadly described as: a) sampling incoming audio (from microphone), b) performing signal processing functions (such as filtering, fourier transform, filtering and manipulation, inverse fourier transform) c) play-out (via speaker jack)
I believe that the "end to end" round trip timing (a) to (c) would need be in the order of 2 to 5 ms for the application to work in the real-world.
So, my question is this possible on today's generation of iphones and android phones?
On iOS, it is possible, but not guaranteed. I have managed to get ~6ms (22050 sampling rate, 128 samples buffer size) in my iOS app which does real-time processing of speech input. Take a look at Novocaine (https://github.com/alexbw/novocaine) - which provides a nice encapsulation of Audio Units and makes programming easier.
However, keep in mind that even if you request a particular buffer size, at run time iOS may decide to send larger buffers at longer intervals (=> higher latency) based on resource constraints. For example, if you have requested a buffer size of 128 (~6ms), you MAY end up getting 256 size buffers at 12ms instead. Your app has to take this into account and handle the buffer accordingly.
On Android, unfortunately, low-latency round-trip audio is a much bigger problem. This is because latency is driven by a host of device/manufacturer driven factors like hardware/driver level buffers and these vary from device to device. You can find a discussion of this long-standing Android handicap here: https://code.google.com/p/android/issues/detail?id=3434
My suggestion would be to ignore Android for now, and implement/validate your signal processing algorithms on an iOS device. Later, you can consider porting them to Android.