On Semiconductor have introduced a highly integrated CMOS modem for applications running the Highway-Addressable, Remote Transducer (HART) communication standard for field instruments and masters. The NCN5193 requires minimal external passive components to provide the functions needed to satisfy HART physical layer requirements including modulation, demodulation, receive filtering, carrier detect, and transmit-signal shaping.
The NCN5193 also has an integrated DAC for low-BOM current loop slave transmitter implementation and employs phase-continuous frequency shift keying (FSK) at 1200 bits per second. To conserve power the receiver circuitry is disabled during transmit operations and vice versa. This meets the requirements of half-duplex operation used in HART communcations.
Integrated CMOS HART Modem - [Link]
The RFD900 is a high performance 900MHz, ISM band radio modem covering the 902 – 928 MHz frequency band. It is designed for long range serial communications applications requiring best in class radio link performance.
- Long range >40km depending on antennas and GCS setup
- 2 x RP-SMA RF connectors, diversity switched.
- 1 Watt (+30dBm) transmit power.
- Transmit low pass filter.
- > 20dB Low noise amplifier.
- RX SAW filter.
- Passive front end band pass filter.
- Open source firmware / tools, field upgradeable, easy to configure.
- Small, light weight.
- Compatible with 3DR / Hope-RF radio modules.
- License free use in Australia, Canada, USA, NZ.
RFDesign RFD900 open source RF modem - [Link]
Tronixstuff has released Part 2 (for part 1 click here) of their tutorial series on using a GSM cellular modem with the Arduino. In this part they cover how to use the telephone network to control an Arduino board via a SM5100B Cellular Shield. [via]
Tutorial: Arduino and GSM Cellular – Part2 - [Link]
Tronixstuff has published the first part of their tutorial series on using a GSM cellular modem with the Arduino. In this part they cover hardware interfacing and testing, sending a text message, and embedding data within a message. This part is the latest is a series of Arduino tutorials posted by Tronixstuff. [via]
Tutorial: Arduino and GSM Cellular – Part1 - [Link]
The Semtec DP1205 RF module is the core of the modem. This module is a Semtec XE1205 transceiver plus an antenna switch and other required discrete components that are not built on the XE1205 chip. The XE1205 is a very generic 900MHz FM module without any built-in protocol logic. It is very similar to the modules produced by Linx Technologies. The module has an SPI interface for changing between transmitter and receiver modes and for setting the RF frequency and the FM frequency deviation. The data connection directly drives the FSM circuity. For this project, the module uses a 100KHz deviation. The transmission power is 15DBm.
A FCC Legal Frequency Hopping Spread Spectrum USB RF Modem – [Link]
Rob Arnold writes:RF is just way too cool not to use in your designs. But if you’re a newbie like me it is difficult to successfully build solid RF transmitters and receivers. When I started out I didn’t realize that the larger breadboard I was working off of was causing a lot of the signal deviance because the metal traces on the breadboard worked like small capacitors and changed my circuit dynamics. So after much research I found the Reynolds Electronics RWS and TWS 434 RX/TX pair. I looked into a similar product by MING Microsystems and Radioshack but the Reynolds were superior in performance, cost and ease of use. So with that and two PIC16F84’s I started working on my serial RF link from my control interface (Joystick) to my robot. [via]
RF Modem Robotics Project - [Link]