Context:
I am to do a project which is to compare ZigBee to Bluetooth Low Energy (BLE).
The parameters which the technologies are to be measured is RSSI over range and power consumption.
Both technologies/modules must be connected to a battery of some sort. Will be decided later in the project.
Both modules shall be controlled individually by a MCU/Arduino/Raspberry Pi which shall not be powered by the battery. So the only thing that should be powered by the battery is the ZigBee and BLE module.
I am considering to use the XBee 3 module as the ZigBee module. I'm aware that it comes with a BLE possibility aswell, but i need to evaluate two different modules, which is why i can't just use it both for the ZigBee and BLE testing.
This leads to the following questions:
(Questions are based on the context above)
Questions:
Any suggestions for BLE modules which are enable to sleep for several minutes before being pulled active again?
Any suggestions for ZigBee modules which operates in the 868MHz range, which is able to sleep for several minutes before being pulled active again?
Is there a problem with having the microcontroller connected to a different power-source than the ZigBee/BLE module?
Looking forward to your replies.
There are lots of options, but I'd recommend looking at Nordic Semiconductor's nRF528xx series and use the nRF52 DK, or Texas Instruments CC2640 series and use the CC2640R2F LaunchPad.
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Different power source is not a problem, but you need to have them referencing the same ground plane. If the distance between devices if more than a couple feet, you may need to do some isolation via optical or magnetic interfaces.
1) HM-10 board (CC2541 inside) might be a good option for what you are trying to do.
2) Zigbee S3B will do your work . you can select the module with required freq range
3) Yes, Different power sources is fine as long as every module has a common ground as already answered above
Related
I have a fairly complex project done on Arduino2560, which I want to port to a standalone Atmega328. My problem is that one feature in the project is that it can communicate with my computer via serial (I made a C# program to handle it on the computer side, using the COM3 port). However, Arduino uses the USB communication for a virtual serial port, and I got a bit confused about how it could be done for the Atmega. It has the RX-TX lines, but what's next? Maybe use some serial-USB converters? What's the best approach for this? Is there anything I should be careful about?
Thanks.
Considering you mention a specific port COM3 on your computer I guess we can assume you have a native RS-232 port (one of those with the sub-D9 male connector that we were used to in the old days but are not so common anymore).
If that's the case, then you can get an RS232 level shifter. You'll just have to make the connections to RX, TX, Vcc, and GND and this device will change the RS-232 voltage levels to whatever your board requires (most likely 5V or 3.3V). Some (maybe most) high-end development boards include this kind of level shifter so maybe check yours in case you already have it (if you do you'll probably see a MAX232 IC somewhere). Or if you are crafty you can also DIY.
If you prefer to connect to a USB port (then, of course, it won't be COM3unless you explicitly change the configuration on Windows Device Manager) you can go for a USB-to-serial adaptor. On that front, you have many choices, starting from the cheapest at maybe 5$, but I'd rather choose one based on the FTDI chip, which is nowadays quite ubiquitous and has proven its reliability. This one is a good example, and at the same cost as the level shifter.
Now, are there any differences between using the native RS-232 or the USB adaptor? The answer is, for most practical purposes, no. If you go to the fine details, like buffer sizes, there will be differences, but if you need to go there you'll need to study the details in both cases to see if the port you have (or the one you're planning to add) meet your needs. For most scenarios, I would choose the USB, if only because you have it everywhere (most laptops don't have a native RS-232).
All of the above (based on RS-232 and/or USB) will work fine for cables running up to 5 meters (~15 ft.) for USB or maybe 10 to 15 meters (~30-45 ft.). This should be enough for most hobbyist or at-home projects. If you want to run longer cables you'll have to go for something like RS-485.
If you choose now the USB adaptor and you think you might need to relocate your board in the future to end up more than 20 meters (15 of RS-232 + 5 of USB) away from your computer just make sure your adaptor includes a TX Enable signal (TXEN). Most adaptors based on the FTDI chip will have this signal on a pin (like the one I linked above), and that will make your life way easier if you want to use RS-485 on a two-cable half-duplex bus.
EDIT: based on the feedback below there is new info that deserves a quick update.
First, you don't have an old school RS-232 port on your PC and second you have to design the connection on the microcontroller's side.
With that in mind it's clear you have to go for the USB solution. But you need to choose if you shift both sides to RS-232 levels or you stay at TTL. That decision depends again on the length of your bus. If it'll be really short (up to 2 meters) then you can stay on TTL, otherwise better shift to RS-232 to be on the safe side. There are many people who will tell you they have much longer serial links but how reliable they are you'll never know.
Since you have to design the board, I guess it makes sense to integrate the MAX232 and a sub D-9 connector there and get the cable you mentioned for your PC.
Or, you can add only a connector on the board and get the Sparkfun level shifter I linked above for the micro's side plus the same USB to RS-232 for your PC.
I have a project involving communication between a raspberry pi 2 and arduino uno, does it matter of the shields are different ?
Second when communicating do they both need to be coded in the same language?
Does anyone know of any tutorials on this subject?
Thanks
As long as both shields comply with CAN spec, and the software in both ends uses the same configuration (bitrate, CAN message structure, CAN IDs) there should be no problem in using different platforms and different languages to communicate between them.
Note that in many shields the power for the CAN transceiver is provided from the "vehicle" and not from the platform that you use (arduino, RPi) to provide better protection to the platform, and you might need to provide such power source (the arduino might do, (although the RPi can provide 5V from pin 2).
I know both are bluetooth smart devices. I need to know whether both can be used for the same applications. If not what do they have in common and what is different about them?
A sensortag can be configured to be an iBeacon, but it is designed to be a more generic Bluetooth LE device that can be put to many other uses as well, providing many other Bluetooth services.
An iBeacon is a very specific type of Bluetooth LE device, and many types of iBeacons can only perform that one function.
Because a sensortag is so generic, it is not optimized to be an iBeacon. Its battery, for example, will not last a super long time when acting as an iBeacon.
A TI "Sensortag" is basically just an eval board for the CC2540 / CC2541 BLE chips.
Most hardware "iBeacon" implementations use either that chip, or the competing NRF51822, on a more specialized custom board.
In either case, the transmission of "iBeacon"-formatted BLE advertising packets is controlled by the custom firmware loaded into the device.
The duty cycle, which is the major determination of power consumption, is also determined by the firmware. The Sensortag does have some other onboard peripherals, but if the design is sane it should be possible to get those into a negligible powered-down state.
Answering #TimTisdall comment (below), the following link is a 3rd party, non-official iBeacon-enabled firmware update for TI's 2541DK SensorTag hardware:
hex firmware files, demonstrating iBeacon on the cc254x
For more info regarding SensorTag, see:
http://www.ti.com/ww/en/wireless_connectivity/sensortag
&
http://www.ti.com/tool/CC2541DK-SENSOR
This question was a bit ahead of the time and here are some updates: The SensorTag now officially supports iBeacon technology. Information on how to configure it to act as an iBeacon is described in the wiki.
As davidgyoung already pointed out: it wasn't build to solely work as an iBeacon, so it may come with reduced battery life. On the other hand, it provides more functionality, which makes it a valuable tool for development at a good price tag.
As noted before the SensorTag has many other sensors on board. Using a "generic" iBeacon firmware on the SensorTag results in a high current consumption. The unused sensors need to be put into sleep mode (I believe it was the Gyro implementation, which eats a lot of power when not configured correctly in sleep mode).
My application will be having many microcontrollers with sensors monitoring a large area. The application requires all these microcontrollers to send the data to the master microcontroller. From the master microcontroller the data must go to desktop PC via serial connection and to a mobile application. Which one (Zigbee/GSM) will be suitable?
This completely depends on what you mean by "Wide Area." A few hundred square meters? A few hundred square kilometers? Zigbee is more cost effective and simpler to implement if you're within range. You could even mesh your nodes together to extend the collective reach of your network. Otherwise, well, you have no choice but to use something like GSM.
RF Line-of-sight range on readily available XBee Modules can be up to 2 miles. Higher power models can be had with 40 mile LOS range.
If you are within range, I would recommend ZigBee as that saves you the cost from having a sim-card in each device.
Buy zigbee modules that have SDK and HW ability for mesh networking. That will give you ability to talk to far nodes via routing nodes. Unfortunately zigbee can not do adhoc mesh networking so you need to know in advance what your routers will be, or to program your nodes routing your self. Another 802.15.4 module (by Synapse) can solve all this since it supports ad hoc mesh networking for you via SNAP protocol. It is not zigbee compatible, but Synapse modules are already adopted by big players like Garmin so this should not bother you. They also run much longer on batteries then zigbee modules. They can also give onboard analog and digital IO accessible without need for additional MCU (although you can connect it and give control to it if you wish). There is also USB stick that will enable your PC to talk to these modules.
What I have in mind is having a number of sensors (temperature, accelerometer, sound level meter) that are controlled by a micro controller. What I want to do is take this information and transmit it wireless to a laptop that will take this information and put it on to a web server using Zigbee. I don't know where to start.
Since you don't have any hardware as of yet, you might want to give the Arduino a try. The hardware is affordable, can be connected to your system via USB while being programmable in-system.
The basic board can be extended via so called "shields", which offer additional features. In your case, the XBee shield would be appropriate. Connecting your laptop to a XBee module is as simple as using Sparkfun's breakout board and a mini-USB cable.
The Arduino has a large community, so you will find a lot of resources, like books, online material, example code etc.
We also provide wireless modules that can be used for serial data transmission. They can be found at www.starmanelectric.com Our modules are very similar to the xbee, but more plug and play. They can be a great for going wireless for the first time. Our devices are designed to function like a "wireless cable" so if you're used to using wires then you'll be up and running in no time at all. We also have circuit examples for transmitting to a laptop serial port or USB. Any micro-controller will be fine for this application, as long as it has a serial port and a few ADCs to sample your data. Our modules also provide simple analog in/out which can run in parallel to the serial. If you want to compare to other systems, I would google "wireless serial modules"
Regards,
Michael
Starman Electric