Baby monitor system
A baby monitor system has a child unit with a child transducer that receives and converts incoming audio signals to an incoming analog signal. The child unit has an analog-to-digital converter that converts the incoming analog signal to outgoing digital data. A child unit microprocessor converts the outgoing digital data to a wireless signal and a transmitter of the child unit transmits the wireless signal. A parent unit has a receiver that receives the wireless signal and converts the wireless signal to incoming digital data. A parent unit microprocessor processes the incoming digital data. A digital-to-analog converter in the parent unit converts the processed incoming digital data to outgoing analog information. A parent unit transducer converts the outgoing analog information and transmits outgoing audio signals representative of the incoming audio signals.
1. A baby monitor system comprising:
a child unit having a child transducer that receives and converts incoming audio signals to an incoming analog signal, an analog-to-digital converter that converts the incoming analog signal to a digital representation of the incoming audio signals, a child microprocessor that generates a data stream from the digital representation, and a transmitter that transmits a wireless signal representative of the data stream on a selected channel of a plurality of channels; and
a parent unit having a receiver that receives the wireless signal and converts the wireless signal to incoming digital data, a parent microprocessor that processes the incoming digital data, a digital-to-analog converter that converts the processed incoming digital data to outgoing analog information, and a parent transducer that converts the outgoing analog information into outgoing audio signals representative of the incoming audio signals;
wherein the parent microprocessor is configured to tune the receiver in accordance with a channel selection scan for the selected channel, the channel selection scan comprising an attempt by the parent microprocessor to detect valid data on a particular channel of the plurality of channels using an identification code stored on both the child unit and the parent unit but not included in the data stream.
2. A baby monitor system according to claim 1 , further comprising:
a child amplifier in the child unit that amplifies the incoming analog signal and sends an amplified incoming analog signal to the analog-to-digital converter.
3. A baby monitor system according to claim 1 , further comprising:
a parent amplifier in the parent unit that amplifies the outgoing analog information and sends amplified outgoing analog information to the parent transducer.
4. A baby monitor system according to claim 1 , wherein the attempt by the parent microprocessor decodes any data on each channel to determine whether the data is the wireless signal.
5. A baby monitor system according to claim 4 , wherein the receiver automatically scans the plurality of channels.
6. A baby monitor system according to claim 4 , wherein the parent unit determines whether the data is the wireless signal by measuring a good data rate on each channel until locating a good channel of the plurality of channels where the good data rate is above a minimum threshold good data rate.
7. A baby monitor system according to claim 6 , wherein the parent unit automatically verifies a good connection by periodically re-measuring the good data rate on the good channel.
8. A baby monitor system according to claim 6 , wherein the parent unit first operates in a fast scan mode until locating the good channel.
9. A baby monitor system according to claim 8 , wherein the parent unit operates in a channel tweak mode upon locating the good channel by checking the good data rate of a next lower frequency channel and a next higher frequency channel relative to the good channel.
10. A baby monitor system according to claim 9 , wherein the parent unit operates in a normal operation mode upon determining that the good channel has a higher good data rate than the next lower and next higher frequency channels.
11. A baby monitor system according to claim 7 , wherein the parent transducer emits a good connection signal as long as the parent unit detects the good data rate on the good channel.
12. A baby monitor system according to claim 4 , wherein the child microprocessor determines which channel of the plurality of channels over which to transmit the wireless signal.
13. A baby monitor system according to claim 1 , wherein the child microprocessor determines the selected channel of the plurality of channels for transmission of the data stream.
14. A baby monitor system according to claim 1 , wherein the child unit comprises a user push button to cause the child microprocessor to select a different channel of the plurality of channels.
15. A baby monitor system according to claim 1 , wherein the child microprocessor uses the identification code as a key for encryption of the digital representation of the incoming audio signals, and wherein the parent microprocessor uses the identification code for decryption of the incoming digital data.
16. A baby monitor system according to claim 15 , wherein the encryption uses a binary logic operation on the digital representation and the identification code.
17. A baby monitor system according to claim 15 , wherein the attempt by the parent microprocessor includes a checksum calculation after the decryption.
18. A baby monitor system according to claim 1 , wherein the child and parent microprocessors use the identification code as a seed for respective pseudorandom number generators to determine a frequency hopping sequence for the wireless signal.
19. A baby monitor system according to claim 1 , wherein the child and parent units are paired via storage of the identification code in the parent unit after a startup sequence in which the parent unit scans all available channels to find an identification code packet transmitted by the child unit.
20. A baby monitor system comprising:
a child unit having a child transducer that receives and converts incoming audio signals to an incoming analog signal, an analog-to-digital converter that converts the incoming analog signal to a digital representation of the incoming audio signals, a child microprocessor that generates a data stream from the digital representation, and a transmitter that transmits a wireless signal representative of the data stream on a selected channel of a plurality of channels; and
a parent unit having a receiver that receives the wireless signal and converts the wireless signal to incoming digital data, a parent microprocessor that processes the incoming digital data, a digital-to-analog converter that converts the processed incoming digital data to outgoing analog information, and a parent transducer that converts the outgoing analog information into outgoing audio signals representative of the incoming audio signals;
wherein the parent microprocessor is configured to tune the receiver in accordance with a channel selection scan for the selected channel, the channel selection scan comprising an attempt by the parent microprocessor to detect valid data on a particular channel of the plurality of channels
wherein the parent unit determines whether the data is the wireless signal by measuring a good data rate on each channel until locating a good channel of the plurality of channels where the good data rate is above a minimum threshold good data rate,
wherein the parent unit automatically verifies a good connection by periodically re-measuring the good data rate on the good channel, and
wherein the parent transducer emits a good connection signal as long as the parent unit detects the good data rate on the good channel.