I recently is studying tire pressure monitoring system(TPMS) base on the FXTH870911DT1.
I use the MC33696 evaluation board and MC9S08RG60 demo board as the receiver.
I have now realized the communication between the FXTH870911DT1 and the MC33696,but there is a problem,A detailed description is as follows
As the transmitter,FXTH87 configuration information is as follows
1.Mode:FSK
2.Frequency:433.92MHz
3.Band rate:4800
4.Frame format:Praemble + ID + Header + data + EOM
0B1111 + 0B110101 + 0B100001 + 0B00001111 + EOM(RFCR2_EOM = 1)
RF Buffer:0xFD,0x61,0x0F
TPMS_RF_SET_TX(23);
As the receiver,MC33696 configuration information is as follows
1.Mode:FSK
2.Frequency:433.92MHz
3.Band rate:4800
4.DME:1
5.ID:F5
6.Header:E1
I receive the data by the Hyperterminal(MC33696 evaluation board + MC9S08RG60 demo board),now I can receive the 0B00001111(0x0F),the data is correct,
but I receive the 0B0000111111111111 (0x0FFF)randomly.
I try to change the data,RF Buffer:0xFD,0x61,0xF0,I receive the all data is 0B1111000011111111(0xF0FF) or 0B1111000001111111(0xF07F)
Then I clear the RFCR2_EOM,but all of the phenomenon is the same as described above.
I don't know why I receive the 0xFF and 0x7F eatra?
Can anyone help me.Thanks.