The RF modules you offer are very interesting and - especially the TRF-2.4G - really low cost.
However there are two major drawbacks:
-using the 2.4G needs programming (data integrity, retransmission) and testing.
-the SMIRF’s 40kb/s is SLOW and the module is comparatively large and low range. (consider transmitting images of the Agilent cam without the cost of the mobile phone network)
For many projects, a BLUETOOTH SPP module will circumvent these problems.
A module with SPP (Serial port profile) makes for a virtual RS232 cable. Real net data transfer is up to 265kBit/s. That is verified, completely correct data transferred.
Class 1 has a range of 100-500m (depending on antenna, 200m with a good (e.g. dipole) antenna) at 100mW.
Power consumption is 30mA at 3V with the new modules. They use SPREAD SPECTRUM modulation and are therefore immune to many RF-problems.
They also interface to any nice small USB-Bluetooth dongle.
Price is around 80-100$ retail but as low as 30$ in quantities of several hundreds. This will surely come down in the next months and years.
The best modules I found are F2M03C1 of free2.move.se and Promi-ESD. I don’t know the real manufacturer of Promi-ESD ( it is available for example at lemosint.com).
As it is cumbersome (transaction cost) to order the modules directly at the manufacturers, I would really like to see a retailer like spark fun electronics carry them.
Bluetooth is fun for integrating in, yes. At least a single serial port profile makes it easier to control via microcontroller, instead of having to worry about all the complexities of the protocol. Bluetooth might be able to do that, but I too have had flaky problems with Bluetooth, although it’s mostly been between a cell phone and a PDA. The fact that bluetooth has connection numbers and profiles defined in the hardware design has always pushed me away from it. Mind you, barring some 802.11b implementation, it’s still the fastest and most available way to connect a project to a computer wirelessly, although I’ve only seen modules with Class 1 ranges of 100m max.
To each their own I need speed and range (Anyone got a good web link for just some 9Xtreme modules from Maxtech?), or mesh and battery consumption (Nordic, Zigbee).
MGP: That Bluestamp module is a real alternative and seem competitive in price (Considering that a US-$ is worth just 0,77 Eurocent and free2move’s prices are in Euros.). Unfortunately in the “spec” sheet power consumption is stated 120mA*3V at Tx. I hope that is during actual Tx only and reduces to around 40mA because of Tx idle-time at lower baud-rates (750kBit/250kBit = factor of 3).
SOI_Sentinel: If you need more range, two patch antennas (=highly directional antennas) could increase effective communication range to up to 1,2 km. I took this number from the Promi-ESD manual at http://www.bluetoothupgrades.de/pdf/Pro … ual1.1.pdf
How do you guys find these vendors? We’ve been trolling the internet for awhile looking at different wireless implementions. Just goes to show you can never get a good grip without a little help. Thanks for the link to our neighbors down in Denver.
I need speed and range (Anyone got a good web link for just some 9Xtreme modules from Maxtech?), or mesh and battery consumption (Nordic, Zigbee).