I understand that there are two types of devices in Bluetooth 4.0: dual(SmartReady) and single (Smart).
For one of the use cases, I need to use dual mode device.
When a bluetooth is ON in a dual mode device, does it mean that both bluetooth classic and LE are ON? Is there a possibility of Bluetooth LE "on" and bluetooth classic "off" configuration in a dual mode device?
If dual mode device is ON and is in idle state, does it achieve the power savings as that of single mode device ( ie only Bluetooth LE ON)?
I don't think you can configure what part to be on or off. At least not from the application level.
This site claims that
Dual-mode devices will rarely gain in power saving because they need
to support both technology implementations; the power savings will
only be achieved with the single-mode option.
But it doesn't specify the state in which the device is in.
Related
I'm attempting to use a classic bluetooth chip to possibly send out signals to another device with a classic bluetooth chip.
Now would it be possible to create a beacon with classic bluetooth?
You certainly can. A Bluetooth LE beacon typically sends out regular advertisements with a unique identifier that can be picked up by a receiving device (typically a mobile phone) doing a Bluetooth LE scan. Since you can also send out advertisements and do scans with classic Bluetooth, you could build the same thing with this technology.
The main disadvantage is that classic Bluetooth uses much more power, both for transmitting the beacon signal and more importantly for doing the scans. So if you are using mobile phones to detect the beacons the battery drain will be much higher than if using Bluetooth LE.
Does Apple allow dual mode BLE connectivity in iOS? It seems that if BLE iOS apps could communicate to dual mode Bluetooth devices in BR/EDR mode, one wouldn't need to join the MFI program.
The CoreBluetooth library allows communication with a BLE peripheral using the GATT profile only.
The use of other profiles (aside from generic HFP/A2DP/AVRCP which is supported by AVFoundation and keyboards which have native HID support) requires going through the MFI program. So for example SPP.
And yes, iOS does not prevent using BLE for data communication while using an audio profile to the same device at the same time.
As of iOS 13 you can connect to both BLE and BR/EDR with CoreBluetooth, as introduced here.
I searched on bluetooth.com , bluetooth.org but I didn't find any explanation about Bluetooth Smart Ready Device being low energy.
I know Bluetooth Smart Ready is dual mode. (Backward compatible)
My question is When Bluetooth Smart Ready is connected to older Bluetooth device, is it still in low energy mode or does it require more power(like older Bluetooth Devices) ?
Short answer: no it is not in low energy mode because it is not using the low energy subset of Bluetooth v4.0.
Long answer: Bluetooth v4.0 defines two types of transceivers:
Dual-Mode Devices (aka Smart Ready Devices): Dual mode devices include all the features of standard Bluetooth v4.0 (Classic Bluetooth + Bluetooth High Speed + Bluetooth Low Energy); BLE functionality is integrated into the existing Bluetooth controller. Dual mode devices, such as PCs and Mobile phones, can utilize the full package versions of the technology running side by side.
Single-mode Devices (aka Bluetooth Smart): single mode devices
implement the low energy protocol stack only. The single mode devices
benefit from the low power consumption and low cost of implementation
provided by v4.0. Therefore, the devices are cheaper and consume
less power than dual mode devices.
Hope this helps.
Bluetooth Smart means Bluetooth 4.0. The only common in Bluetooth Smart and the older versions is the frequency range.The communications is vastly different, requiring different radio hardware too.
So if a device is dual mode, it can either use the low energy, or the standard communication. And because of this, in standard mode, the energy consumption is the same as with the standard devices.
No, When a backwards compatible Dual Mode/Smart Ready device is connecting and transmitting on Bluetooth 2.1, 3.0 or EDR it is not Low Energy.
What makes low energy low energy is the short burst transmissions, packet size and the way the processing works. Being Dual Mode / Smart Ready just combines the necessary chips and antenna into one package for ease of manufacturing and design.
Bluetooth Smart Ready = Dual Mode, i.e. it can switch between BR/EDR (Classic) and BLE.
For BLE, it is first and foremost the protocol that makes it "low energy", i.e. low consumption.
So, when the Smart Ready device works in BLE mode, it is low energy. When it works in Classic mode, it is not low energy.
I have some starter kit board based on Atmel ARM926 400MH. Powered by linux.
And I need to control power of USB, i.e. switch it off and switch it off.
I try to research for use sysfs, but there is no information about switching on/off.
You either can’t control USB power, or the OS will control it for you. As noted in this comment, “... users shouldn't be conscious of this layer.”
Port power might be hardwired to be always present, but more often hardware allows control by the driver. One example I’ve seen, host port through a 3320 USB PHY should have port power automatically enabled by CPEN output.
This area was enhanced with runtime power management framework introduced in 2.6.32 kernel. Details can depend on SoC and specific board support. New features can allow user space control to prevent auto suspend and resulting powerdown; otherwise, by default, USB should power down in suspend modes.
Lots more info in Regupathy.
Can a WindowsCE device connect so more than one BlueTooth device? The device needs to both serve as a BlueTooth hands-free speaker for a phone and connect to a third device via a serial BlueTooth connection.
Can an application do this without the need of a speciel driver?
You must understand that Windows CE is a modular OS and any specific platform capabilities are implemented by an OEM. An OEM can create a Windows CE device with absolutely no Bluetooth support or they might choose to implement just a Bluetooth client profile (say as a bluetooth audio device) or they may choose to implement a Bluetooth server so they can consume a Bluetooth serial device. They may also choose to implement both. Beyond what the OEM does in software, the hardware itself might allow only one or the other (or both or neither for that matter).
The short of this is that we can't actually answer your question becasue there is no generic answer that fits all devices. You have to ask the Device OEM what they support and if they can extend that support if they don't support what you need.