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AN118 

 
 

Rev 1.1 | Page 1 / 31 

 

www.cmostek.com 

 

 

 

 

 

 

Introduction

 

The purpose of this document is to provide the guidelines for the users to configure the CMT2250A on the RFPDK. The  part 

number covered by this document is shown in the table below. 

 

Table 1. Part Number Covered in this Document

 

Part Number 

Description 

CMT2250A

 

True single-chip, ultra low power and high performance device that consists of an OOK RF receiver, a 

data decoder and 4 data output pins for various 300 to 480 MHz wireless applications. The decoder 

supports 1920, 1527 and 2262 packet formats. The chip is part of the CMOSTEK NextGenRF

TM

 family, 

which includes a complete line of transmitters, receivers and transceivers.

 

 

The RFPDK (Radio Frequency Products Development Kit) is a PC application developed by CMOSTEK for the NextGenRF

TM

 

product line. Differing from traditional RF chip configuration methods, which usually require complex software programming and 

register-based controlling, the RFPKD revolutionarily simplifies the NextGenRF

TM

  product configurations. The user can easily 

complete the product configuration by just clicking and inputting a few parameters. After that, the product can be directly used in 

the RF system without performing any further configurations. 

 

To help the user  to  develop their application with CMT2150A and CMT2250(1)A easily, CMOSTEK provides 

CMT2150A/2250(1)A  One-Way RF Link Development Kits

  that enables the user to quickly  evaluate  the performance, 

demonstrate the features and develop the application. The Development Kits includes: 

 

 

RFPDK 

 

USB Programmer   

 

CMT2150A-EM (Tx module) 

 

CMT2250A-EM (Rx on-off control module) 

 

CMT2251A-EM (Rx PWM control module) 

 

 

 

AN118 

CMT2250A Configuration Guideline

 

Copyright © By CMOSTEK   

Summary of Contents for CMT2250A

Page 1: ...developed by CMOSTEK for the NextGenRFTM product line Differing from traditional RF chip configuration methods which usually require complex software programming and register based controlling the RF...

Page 2: ...y Exit 14 3 4 1 Application Example 1 Fixed Duty with Rx Early Exit 14 3 4 2 Application Example 2 Wake on Preamble with Rx Early Exit 15 4 OOK Settings 16 4 1 Demod Method 16 4 1 1 Fixed Threshold Me...

Page 3: ...AN118 Rev 1 1 Page 3 31 www cmostek com 6 2 Factory Code 28 6 3 Study RSSI TH 29 6 4 Study Time Window 29 7 Document Change List 30 8 Contact Information 31...

Page 4: ...250A can be CMT2250A EM V1 0 provided by CMOSTEK or the PCB designed by the user with CMT2250A Figure 1 CMT2250A Configuration Setup Start the RFPDK from the computer s desktop and select CMT2250A in...

Page 5: ...AN118 Rev 1 1 Page 5 31 www cmostek com Figure 3 Advanced Mode of Device Control Panel...

Page 6: ...rts OOK demodulation 2 3 Symbol Rate With OOK demodulation CMT2250A supports 0 1 40 0 ksps symbol rate The symbol rate tolerance of the device is from 25 to 25 of the Symbol Rate configured on the RFP...

Page 7: ...l Stabilizing Time This defines the time for the device to wait for the crystal to get stable after it is powered up The user shall select one of the six options provided on the RFPDK that is most sui...

Page 8: ...s WOR is on Basic Advanced Rx Time Ext The extended receive time in duty cycle mode the range is from 0 04 to 2 683 043 00 ms It is only available when the Wake On Radio is turned on 200 00 ms Advance...

Page 9: ...r regularly to adept to the changeable environment and therefore remain its highest performance The device will continuously receive any incoming signals during the RX state and perform the decoding t...

Page 10: ...ms Set the Rx Time to 1 second which is much longer than the packet length Let the Tx device to send out 3 continuous data packets in each transmission Because the Sleep Time is very short the non rec...

Page 11: ...nger than the packet length times two plus the packet interval which is determined by the Tx setting symbol rate number of symbol per packet etc This ensures that the receiver always has a chance to c...

Page 12: ...ceiving When the Rx timer is timeout at 400 ms the device switches back to the SLEEP state and repeat the same cycle continuously until it is powered down In this example the non receive time is 5 000...

Page 13: ...h is 16 symbol SLEEP XTAL TUNE RX EXT RX Preamble time SLEEP XTAL TUNE RX Data Packet Data Packet Figure 14 The Transmitted Preamble Length Also as shown in the above figure for the Tx device the tran...

Page 14: ...NA Wake On Radio Off Preamble NA Rx Early Exit On Valid Reception 1 packet This example is based on the one descript in Chapter 3 3 1 When no signal is being transmitted the device works in the fixed...

Page 15: ...in Chapter 3 3 2 Because the Rx Early Exit function is turned on and the Valid Reception is set to 2 packets the device automatically exits the RX state as soon as 2 identical valid packets are succes...

Page 16: ...6 9 12 or 15 2 Advanced Peak Drop Rate The RSSI peak drop rate the options are 1 step 4 symbols 1 step 2 symbols 1 step 1 symbols or 1 step 0 5 symbols 1 step 4 symbols Advanced 4 1 Demod Method The O...

Page 17: ...ws the system to only receive the signals whose strength is above a preset value which is helpful for the user to control the communication distance between the Tx and the Rx 4 2 Fixed Demod TH This p...

Page 18: ...e longer it takes for the peak to drop to the noise floor the more 0 the system can demodulate In practice the bottom of the dropping is the noise floor which varies depending on the different environ...

Page 19: ...and 8 symbols bit in 2262 mode 3 Advanced Valid Reception This defines how many identical packets the device consecutively received represent a valid reception the options are 1 packet 2 packets 3 pa...

Page 20: ...ymbol or 32 symbol None Basic Advanced Address Sync ID Length The range of the Sync ID Length is from 1 to 32 bits 32 bits Basic Advanced Address Sync ID Value The value of the Sync ID has the range f...

Page 21: ...Packet Structure The study packet is used for the device to learn the Sync ID from the transmitter in order to pair with the transmitter It contains an optional Preamble a 32 symbol Head_S a Sync ID...

Page 22: ...CMOSTEK has defined a 1527 Study Packet to support the ID study in 1527 mode The traditional packet introduced here is called the 1527 Normal Packet Figure 31 1527 Normal Packet Structure Table 12 Con...

Page 23: ...sent and received starting from the LSB For example if the Sync ID Value is set to 1 the binary value of the Sync ID is 0000 0000 0000 0000 0001 In this case bit 0 1 is received first and bit 19 0 is...

Page 24: ...l By using the CMOSTEK products the user does not need to adjust the OSC to define the symbol rate because the symbol rate is directly programmed The Bit Format is fixed at 8 symbols per bit Address S...

Page 25: ...valid 2262 Sync 5 1 8 2262 Bit Format In 2262 packet a single bit is constructed by 8 symbols as shown below Please note that only the Address Sync ID field and the Data field have the unit of bit In...

Page 26: ...t is set to 2 packets the device only updates the values of the data pins after consecutively receiving 2 identical valid packets Setting this parameter to 4 packets leads to the highest reliability o...

Page 27: ...t the data pins back to their default values on the receiver The default values of the data pins are all 1 In 1920 and 1527 the number of bits of this code is fixed at 4 In 2262 the number of bits of...

Page 28: ...refore the two devices are paired The Sync ID which is one of the elements of the packet is sometimes called Addressed in some communication protocols The lengths of the Sync ID are different in the d...

Page 29: ...ance in which the device can study the Sync ID from the transmitter It is suggested for the user to perform on field testing and adjustment of the transmitting power of the Tx and the Study RSSI TH of...

Page 30: ...w cmostek com 7 Document Change List Table 15 Document Change List Revision Chapter Description of Changes Date 0 8 Initial released version 2014 07 29 1 0 2014 08 13 1 1 3 Updated Figure 10 and relat...

Page 31: ...r inaccuracies and specifications within this document are subject to change without notice The material contained herein is the exclusive property of CMOSTEK and shall not be distributed reproduced o...

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