Hi, I’m a Senior of engineering working on my senior project. One of the parts of my project requries a long range Wireless Mouse and Keyboard to be used around the house. I most likely will be using either a combination keyboard trackpad with 1 usb connection or two seperate devices with usb connections. Long range is a high priority but not too essential, obviously i’m not in the market to create something that does not exist. I am confident I have the ability to research and engineer this project, but my problem is getting started. So I am looking for help, with RF transmitters and Bluetooth and even wifi available, what is the best option for this? Money is not a concern. Also, if someone could just describe the functional flow such as signal > microcontroller > transmitter. That would help, as I am confused as how I can transmit the USB signal which has a D+/D- signal pair into a transmitter that has 1 digital/analog input. Any and all help or opinions would be appreciated.
In addition to Bluetooth, WiFi and proprietary, there’s IEEE 802.15.4, at the MAC and PHY, from many vendors - chips and modules. Chips ($2-5ea) from TI/Chipcon and FreeScale, Jennic (sold by SparkFun, I think), ZMD, Silicon Labs, and many others. Modules ($20@1ea) using these chips from many vendors including MaxStream (XBee/XBeePro), Silicon Labs, Helicomm, et al. See also zigbee.org, as that’s a mesh network layer (3) protocol used optionally with 802.15.4 chips.
Thanks, I actually just have started looking into zigbee, it really sounds promising. So if anyone knows, zigbee seems to have multiple data inputs and mentioned something about auto error correcting? If I can get away without a microprocessor, that would make the electrical engineer in me very happy.
This is the Wireless forum topic - and many have never heard of it because it’s new.
sorry. I will crawl under a rock. I just want to help people know that for $20 or so, you get a complete radio these days, with all the protocols, plug and play. I’ve tried to reference the key vendors rather than one in particular.
Hmmm… someone must have sharpened my “poking fun” stick while I was out.
I have no problem with you pointing out Zigbee solutions where appropriate. I just haven’t seen someone approach a topic on this board with such ferver and enthusiasm to get the word out in some time.
I’m a veteran engineer - more than I’ll admit easily!
The IEEE 802.15.4/ZigBee standards, with many vendors, at the $20-30@1ea price point, with full routed mesh network capability, is simply amazing to me. I have long resisted proprietary products - without competition there is no excellence (or low prices).
I hate to see folks start on a design with a bare bones half-PHY radio and have to design everything on up. And often wind up with something that is point-to-point only- no networking.
So, I think this '15.4 stuff is as profound for embedded systems as Ethernet and WiFi were for their application spaces.
I am almost sold on the zigbee standard. Seems to be perfect as far as range and netwrokability. I noticed the data rate is rather low at 250kbps, i just want to make sure as I can’t find any good information, will this be enough for a USB trackpad and keyboard? I found that old PS/2 ports only had 40kbps so I’m thinking I will be fine. Also does this technology have error checking built in or will i need to use some microcontrollers to take care of that?
IEEE 802.15.4 is the MAC and PHY layer - it defines error detection and correction via ACK and ACK timeout - as is done in 802.11. It also defines MAC layer addresses (64bit) that you can use if you don’t need a network layer protocol.
The 250Kbps is the air link bit rate. The effective speeds, like any wireless data, varies according to media contention and software overhead. I’ve measured 80Kbps net yield for bulk transfers.
A keyboard/mouse app needs just a few hundred bits/sec on average. Tiny data frames, infrequently transmitted. No network layer needed. Arguably, 802.15.4 is an overkill for this application, even without using ZigBee.
