Why paying for complier, licence fee, property rights, antennas, schematics and code? Today: Trailer detection by active RFID

Reference design trailer detection for OBU One Board Unit by using active RFID

Description of the trailer detection by active RFID

At the trailer is a 2400 MHz transceiver working as active RFID tag and it transmits its unique ID each few seconds. By selecting the duty cycle the standby time of the battery will be interfered. Good performed well matched antennas will help to save the battery again. The wired link of the tag reader will be connected to the On Board Unit.

The UART with its 9600 bit is symbolic and can be replaced to SPI. UART or SPI will be converted to CAN-bus. The CAN-bus is more robust and will be wired to to the On Board Unit (OBU) in the truck. RS485 instead of CAN-Bus is also an option. The cheapest concept will be to use the 8051 micro controller to control the GPRS module and the GPS module as well. The active RFID reader and the On Board Unit and active RFID reader will be one and the same. Anyhow, how to save further costs by designing an On Board Unit will be explained later at this blog.

This proposal is using commercial field approved consumer electronic by covering a wide temperature range of -40 to +85° C and with focus on ultra long operating time on battery. The supply voltage range of the semiconductors is from 1,9 to 3,6 Volt. The power consumption is so less that standard coin cell batteries can be used to reach years of operating. By the way, the power consumption of this system on chip is so less, that the self discharge of batteries is even higher. Selecting the consumer components helps with a very low price, too. The necessary further external parts are cheap as well. The antenna is gratis, because it is PCB track only. The used radio link protocol is licence free. There is no money to spend like with ZigBee or Bluetooth. The protocol is secure because it is using an AES128 encryption/decryption and it is field approved with wireless mice, keyboards, remote controls and USB dongles.

The evaluation kits for this application are inexpensive. The minimum are two ready to use 2400 MHz radio modules with ready to use radio link protocol and firmware. Within minutes you will get a working sample. Just plug the coin cell batteries to the 2400 MHz radio modules and code one module in mode active RFID and the other in mode “toggling output pin” and wire a LED. As long the 2400 MHz radio module coded as active RFID will be in the near of the receiving radio module the LED will flash. The next step will be to code the receiving 2400 MHz radio module as a transparent radio to UART link. The received unique ID of the active RFID beacon will be forwarded to the UART. The UART can be wired by USB or RS232 converter to your PC. If you use some kind of terminal software (e.g. Hyperterm on Windows), then you will see the unique ID of the active RFID tag on the screen. The further step is to replace the PC to Smart Phone, GSM/GPS terminal or the Arduino based evaluation kit listed here.
http://www.gsm-modem.de/M2M/m2m-apps/gsm-gprs-gps-shield-for-arduino-board-duemilanove-atmega328/

By using the Arduino based GSM/GPS evaluation kit you have the most options and the big Arduino community in the background.

Trailer detection by active RFID – student evaluation kit

• 2 ready to use 2400 MHz radio modules like in the picture as below
• Free of charge Small Device C-complier or free version of Keil C-compiler
• 1 Smart Phone you already own
• or 1 GSM/GPRS terminal
• or 1 Arduino based GSM/GPS evaluation kit
• 1 USB to CMOS converter cable (just cut the connector of your old Nokia phone data cable)
• or RS232 to CMOS converter by cable or PCB

Options:

• Free of charge tracking map server
• Free of charge maps
• Free of charge 2400 MHz antenna design
• Free of charge GSM antenna design
• Free of charge GPS antenna design
• Free of charge hints and tips how to develop a wireless M2M device

The basic kit has less costs of estimated Euro 35 / USD 50, because you can use components you already own or we can deliver for free.

Trailer detection by active RFID – commercial evaluation kit

• 4 ready to use 2400 MHz radio modules like in the picture as below
• 1 commercial evaluation kits with 2 more special 2400 MHz radio modules
• Free of charge Small Device C-complier or free version of Keil C-compiler
• 1 One Board Unit you ready produce or have
• 1 USB to CMOS converter cable
• or RS232 to CMOS converter cable or PCB

In the commercial we recommend four 2400 MHz radio modules, because then two can stay with radio link protocol and firmware like delivered and two further can be used for compiling and debugging.

Options:

• Free of charge tracking server or commercial tracking server
• Free of charge maps or commercial maps TBD
• Free of charge 2400 MHz antenna designs or consulting on antenna designs
• Free of charge GSM antenna designs or consulting on antenna designs
• Free of charge GPS antenna designs or consulting on antenna designs
• Free of charge hints and tips how to develop a wireless M2M device

The basic commercial evaluation kit is still cheap, because you can use components you already own or select from student version as well. Last but not least you have the freedom to develop the final application yourself, to ask for paid consulting or the place an order for development of prototypes, final product up to production of the whole product including boxing.

Do you have further questions or would like to start the development of your own trailer section? This or another blog post has given you an idea on other 2400 MHz Ultra Low Power radio application? We will be glad to share our more than 15 years in GSM and GPS plus 25 years in radio communication with you. Just send an e-mail by using the form here or by e-mail to harald.naumann (at) gsm-modem.de . We will help with schematic diagrams, ordering code for evaluation kits, sample quantities of all mentions parts and dedicated design in aid as well.

Summary of BOM forTrailer detection by active RFID/ Property rights

• System on chip with 8051, 2400 MHz transceiver core, memory, I/O channels
• 16MHz crystal, some capacitors, inductors, resistors
• Small PCB in FR4
• Antennas as PCB track on FR4 = USD/Euro 0
• Licence free Radio Link Protocol = USD/Euro 0

All together a few bucks for the final PCB including property rights

The selected system on chip contains:

• Enhanced 8-bit 8051 compatible micro controller
• Fully featured ultra low power 2.4GHz transceiver core
• 250 kbps, 1 Mbps and 2 Mbps on-air data rate options
• 32-bit multiplication-division unit
• AES encryption/decryption accelerator
• 16 KB on-chip flash memory, 1 KB on-chip data flash memory
• 512 byte high-endurance data flash memory
• 1 KB on SRAM plus 256 byte of IRAM
• Low power 16MHz crystal and RC oscillators
• Ultra low power 32kHz crystal and RC oscillators
• Flexible real-time counter and three 16-bit timers/counters
• Ultra low power analogue comparator for system wake-up
• SPI master/slave, 2-wire master/slave, and UART, 2-channel PWM
• Programmable resolution ADC: 6, 8, 10, or 12-bits
• Random Number Generator based on thermal noise
• Programmable generic I/O pins

Necessary further components

• 2x 15pF C1 0402 NPO, +/- 5%, 50V
• 2.2nF C3 0402 X7R, +/- 10%, 50V
• 4.7pF C4 0402 NPO, +/- 0.25 pF, 50V
• 1.5pF C5 0402 NPO, +/- 0.1 pF, 50V
• 1.0pF C6 0402 NPO, +/- 0.1 pF, 50V
• 33nF C7 0402 X7R, +/- 10%, 50V
• 1nF C8 0402 X7R, +/- 10%, 50V
• 10nF C9 0402 X7R, +/- 10%, 50V
• 8.2nH L1 0402 chip inductor +/- 5%
• 2.7nH L2 0402 chip inductor +/- 5%
• 3.9nH L3 0402 chip inductor +/- 5%
• 1M R1 0402 +/-5% (or better)
• 22K R2 0402 +/- 1 %
• 16MHz X1 HC49 +/-60ppm

Do you have further questions and would like to start the development of your own wireless M2M app right now? We will be glad to share our more than 15 years in GSM and GPS plus 25 years in radio communication with you. Just send an e-mail by using the form here or by e-mail to harald.naumann (at) gsm-modem.de .