Wireless technologies in embedded systems
Wireless communications are important for mobile devices. Our engineering staff has integration experience of wireless technologies and embedded systems. We can integrate any wireless module into your device design: from simple CIR receiver development for home digital media centers to Wi-Fi and GSM/GPRS modules integration into portable measurement equipment.
We use the following wireless technologies in embedded systems, depending on the range distance and particular application:
- IEEE 802.11 (Wi-Fi)
- Bluetooth
- IRDA
- ZigBee
- RFID
- GSM/GPRS
We often propose to use well-known commercial wireless modules in embedded system design, as a low cost and fast solution for our customers.
Wireless OEM modules are usually connected via the following logical interfaces:
OEM modules can be classified into industrial and mobile application.
There are some important parameters such as operating temperature range and connection interface for industrial modules. Usually, SPI or UART interfaces are used to connect industrial OEM module to the target board. However these interfaces may itself limit the data transfer bandwidth of a wireless connection. Wireless OEM modules for mobile applications are sensitive to a power consumption and dimensions. Also wireless modules with USB connection gain popularity thanks to a wide spread of USB technology on desktop PC market and a multitude of system-on-chip with integrated USB.
OEM modules with UART interface are the most popular due to simplicity of the connection.
Solid background knowledge of software and hardware specifications is required when designing an embedded system with CFIO or SDIO wireless modules. SDIO modules comply to SD I/O card specification while CFIO modules comply to CompactFlash+ specification.
Here are the most common problems faced with during integration of such wireless modules into target embedded system based on system-on-chip:
- Errata or anomaly in SDIO controller integrated in SoC
- Incomplete conformance of timing diagrams to specification
Wireless IEEE802.11b/g (WiFi) OEM module based on Marvell's 88W8385 chipset for mobile application.
Interface: CFIO
Dimensions: 20x20mm
88W8385 chipset application in custom design of WiFi-ZigBee-USB daughter board for Blackfin processors:
Wireless IEEE802.11b/g (WiFi) OEM module based on RealTek RTL8187 chipset for mobile application
Interface: USB
Dimensions: 48x30mm
In Promwad, our engineers possess considerable relevant experience in wireless module selection and integration into target device taking into account marketing and technical requirements. We worked with the following WiFi solutions:
- Marvell: Libertas 88w8686, 88w8385; TOPDOG 88w8687
- Realtek: RTL8187, RTL8180
- Ralink: RT61, RT73, RT2571, RT2870
- Atheros: AR5007UG (former zd1211b), ath5k, ath9k
Low-power RF modules
Low-power RF modules are ideal solution for embedded systems where it's required to transmit small data chunks on a small distance using license-free radio frequency ranges of 433MHz, 868MHz and 2.4GHz.
Electronics devices sometimes require a some kind of remote control like remote car alarm key or remote control for multimedia device. Data amount and transfer rate are rather low in such situations, while power consumption is crucial. It makes no sense to use complicated wireless stacks like Bluetooth, Zigbee or WiFi such remote control devices which do not require inter-operation with radio equipment of other manufacturers.
Typical RF solution consists of radio frequency transceiver or transmitter, low-power microcontroller, antenna and crystal oscillator. RF chip manufacturers often combine transceiver and microcontroller into a single chip package.
After Chipcon acquisition, RF solutions based on CC1xxx and CC2xxx from Texas Instruments became quite popular in low-power, license free RF applications:
- CC1000 — 300-1000MHz transceiver
- ÑÑ1010 — integrated transceiver with 8051 MCU core for operation in 300-1000MHz frequency range. It has support for DES encryption, 3-channel 10-bit ADC and 32Kbytes of Flash memory
- CC1020 — narrow-band transceiver of frequency ranges from 402 to 470 MHz and from 804 to 940 MHz
- ÑÑ1050 — narrow-band multichannel transmitter operating in 300-1000 MHz range
- ÑÑ1070 — narrow-band multi channel transmitter operating in 402-470MHz and 804-940MHz ranges
- ÑÑ1101 — multi-channel transceiver with data packet processing and having SPI port for connecting external microcontroller. It operates in 300-348MHz, 387-464MHz and 779-928MHz frequency ranges
- CC1110 — integrated transceiver with 8051 MCU core for operating in 300-348MHz, 391-464MHz and 782-928MHz ranges. It has up to 32Kbytes of Flash, 21 GPIO, ADC and hardware accelerated AES-128 encryption
- CC1111 — integrated transceiver with 8051 MCU core for operating in 300-348MHz, 391-464MHz and 782-928MÃö ranges. CC1111 has up to 32Kbytes of Flash memory, 8-channel ADC, hardware accelerated AES-128 encryption and support of USB and I2S interfaces
- CC2400 — transceiver for operation in 2400-2483MHz frequency range
- ÑÑ2510 — integrated transceiver with 8051 MCU core for operating in 2400-2483MHz range. CC2510 has up to 32Kbytes from embedded Flash memory and support for AES-128 encryption
- CC2511 — integrated transceiver with 8051 MCU core for operating in 2400-2483MHz range. CC2511 is similar to CC2510 but has additional USB interface
- ÑÑ2550 — multi-channel transmitter for operation in 2400-2483MHz frequency range
Please contact us with any questions or suggestions you may have.
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