# Tag Info

14

Here are most of the BLE chips I know: TI CC254x: old, well known, power efficiency is not great, extremely widely used. power: 27mA@any supply voltage, size: 6x6mm, price: $1.95. NOTE: no DC-DC converter on board. nRF51822: newer, excellent, good if a non-realtime MCU is needed, power: 8.0mA@3V, size: 3.5x3.8mm (more commonly 6x6mm), price:$1.92. nRF8001:...

12

BLE is very unsuitable for even medium bandwidth streaming (audio or video), because it is designed for transfer of few and small data packets with lots of sleeping time in between. This is why it is called 'low energy' and not 'low power' - it reduces the amount of picojoules per bit for small packets with respect to competing standards. Other standards ...

11

This smacks of a grounds-not-tied-together issue. It looks like the USB-to-UART device has only 2 lines going to the Pictail board. I would presume those are just the UART Tx and Rx lines, and not ground. If the grounds of all three boards are not tied together, digital signals between the boards will be interpreted incorrectly and will lead to undefined ...

10

There is another aspect to this that is being missed in the other answers. As per the Core BLE specification, only one advertising channel is being looked at during each scanInterval and is rotated to the next of 3 channels with each interval. So if there is RF interference on that channel you might not see the device even if you have the scanWindow equal ...

10

Bluetooth Basic Rate/Enhanced Data Rate (BR/EDR) is typically used for relatively short-range, continuous wireless connection such as streaming audio to headsets. Bluetooth low energy (LE) is designed to use short bursts of longer-range radio connection, making it ideal for Internet of Things (IoT) applications that don’t require continuous connection. ...

10

The goal of this rather long analysis is to ensure you look like the sharpest RF dude your company has ever hired :) The free space path loss range of a an RF system can be calculated. For a typical class 2 Bluetooth system, assuming +4dBm of transmit power, -70dBm receiver, & unity gain antennas, you will find that the range that gives you 74 dB of ...

10

Use a second DIO to control the pull-up voltage. The output is normally low. Set it high momentarily, read the DIO input, set the output low. simulate this circuit – Schematic created using CircuitLab

8

Well, with 100kbps, you may be able to stream a low quality video the size of a post stamp :-) Without any precision, I will imagine you want HD (not even full HD) @30fps in H264, with average motion (factor 2), an approximate bitrate estimation could be : (1280px*720px)*30fps*2*0.07 ~= 3800kbps So you have to reduce this by a factor 38 (at least !). Say ...

8

They're not the same thing From the Wikipedia article on the Bluetooth specifications: [Bluetooth Core Specification version 4.0] includes Classic Bluetooth, Bluetooth high speed and Bluetooth low energy protocols. Getting a Bluetooth LE device or chip does not mean it will work with Bluetooth Classic. From the Bluetooth LE Wikipedia page: The ...

8

The question has been studied extensively. According to this lecture, at 2.4GHz (microwave frequency as well) the 1/e (63% loss) occurs in 1.4cm. You probably can do better with 9600 baud UART. :-(

7

Consumer Devices Android Samsung phones[specify] HTC phones[specify] Android 4.3 (API level 18) comes with an official Bluetooth Low Energy API. In older versions, BLE was not integrated into the Android API so each manufacturer had/has their own API. Apple iOS iPhone 4S, 5+ iPad 3g, 4g, mini iPod Touch 5g, Nano 7g OS X MacBook Air (Mid 2011/Model 4,x+)...

7

TL;DR version -- if you are trying to do this for just one chip and just yourself (i.e. not a product), it's probably not worth it since you'll need to spend at least \$50 for a programmer. The CC2541 is a combination of a BLE radio and 8051 with either 256K or 128K flash, and 8K of RAM. It has 23 GPIO pins, some of which can be re-purposed as I²C, SPI, ...

6

I assume you have a small beacon PCB that you haven't designed yourself, so you need to work with it as-is. if you're laying out the board, you have more options... 1. Restricting the area covered by a beacon You're onto the right track here - mounting it above the supermarket aisle, or what have you, is probably best, then you can focus the signal into a ...

6

Since this is RF IC, following schematic won't be enough. When building circuits the first time, it's always recommended to follow design guide/ reference schematic as much as you can. That will be a huge step forward to making your circuit work. Since this is RF stuff, you need to go a step further. Being familiar how to interface antenna and which ...

6

Obviously nobody can answer this since we have no idea what your soldering capabilities are, and what equipment is available. Actually think about it. As for whether it is generally possible or advisable, no, not in the general case. Some "modules" are specifically designed to be mounted on another PCB. In that case, yes, it's obviously possible for ...

5

I propose you use a nordic nRF51822 chip that includes the temperature information in advertisement data with an advertisement period of 1 to 2 seconds. Use connectable undirected advertisements. If something wishes to connect to the temperature monitor, implement an appropriate temperature characteristic. Bluetooth SIG Temperature measurement ...

5

Because that is the FCC limit for Class II Bluetooth (10 meter range) transmitters. The FCC determined that 4 dBm was adequate to support the range, and more would increase interference with other stations.

5

Beacon and sensor are terms used in short range networks used for position or presence location systems. BLE - Blue Tooth Low Power - systems are frequently used for this purpose as they interface with Bluetooth systems present in most "smart phones" and the low power consumption of BLE allows long battery life as nodes. The following is BLE focused as this ...

5

The module already includes a microcontroller. The website you linked to says: The on-chip processor has sufficient space for many applications, so a carrier board may only include sensors and a battery. The module is based on a Nordic nRF52832 chip that has an ARM Cortex-M4F, which includes 512Kbytes of flash memory and 64Kbytes of RAM. You'll need to ...

5

I just want to know on what the BLE range depends on other than the following : just from the top of my head (and assuming BLE doesn't use MIMO): Antennas (not all antennas are equally efficient at converting current to radio waves or vice versa. Also, antennas work better in one spatial direction than into others) transmission losses and mismatch losses ...

5

Use 2 GPIOs (we'll call them GPIO 1 and 2) to monitor the switch, and test for switch closure by checking for continuity. This works as follows: Wake up the CPU set GPIO 1 high, check GPIO 2 state set GPIO 1 low, check GPIO 2 state If GPIO2 followed GPIO1, then the switch was closed. If not, no. This improves on pull-up or pull-down since there's no ...

4

The advertisement packet your beacons send can contain custom data. However the space is very limited, around 31 bytes. About 16bytes of it goes to the 128bit "service UUID" of your beacon. The structure of the packet is defined by the bluetooth spec and it does have some overhead, so I'm not sure how much is actually available for the custom data. The ...

4

Take a look at my answer here about low power radios: Low-power wireless module strategy The core problem is that BOTH receive and transmit typically take on the order of 10mA to 30mA for integrated radios. Therefore to get average power down you must use some kind of radio duty ratioing technique (there are many). As an example, ContikiMAC can route ...

4

Your main concern with any wireless module on a low-performance power supply is to design in very heavy decoupling. Coin cells in particular - excluding recheargable lithium ion type (which are very rare) - have internal resistance up to about 100 ohms, so you will not be able to draw more than a couple of milliamps from them. As your BLE113 module is ...

4

If you look at the block diagram on page 20 of your linked datasheet, you'll see that all of the I/O, including the USARTs, go to the 8051 controller. The 8051, in turn, is the only path to the Bluetooth radio section. Therefore, I'd say that the internal microcontroller is required for the module to function.

4

It looks very feasible although you will need to mount the chip onto a breakout board yourself and considering it is only offered in a QFN or BGA package, you will probably need hot air rework or some sort of reflow oven. QFN to DIP breakout boards are very simple and can readily available on eBay or some electronics store like Sparkfun. You will need a ...

4

I don't want to sound negative, but this is a bare chip, that must be interfaced to a (possible on-PCB) antenna. This is highly specialized work, I would not touch it myself. Since you ask here about the much much easier task of connecting the uC part of that chip, I think this is way over your head. If you want to make large quantities of your product, ...

4

This falls under the topic of "permissive changes". The FCC has a document called PERMISSIVE CHANGE POLICY which outlines what can or cannot be changed without requiring a new FCC ID. Under section 2 c). it says, "Part substitution – electrically identical parts may be substituted." I would assume that the two batteries are the same voltage, but perhaps ...

4

It's a bandpass filter. The crossed out waves tell you that frequencies above and below the passband are rejected. The legend says the passband is centred on 2.45GHz. It's not part of the chip, but an external component. The schematic tells you nothing more about it, such as bandwidth, insertion loss, stopband attenuation, etc. Hopefully the text has more ...

4

First, referring to your existing design, the important thing about a PCB antenna is to have no ground plane under the entire antenna, and to follow the layout shown in TI's application note exactly. It's not a bad idea to include the Pi network, it may be useful for during RF testing. You should be able to continue the 50 ohm feed for a little ways, as ...

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