70009 Parallax Inc, 70009 Datasheet - Page 104

• Manufacturer Part Number: 70009
• Description: BOOK UNDERSTANDING SIGNALS
• Manufacturer: Parallax Inc
• Type: Signal Analysisr

Specifications of 70009

• Style: Book
• Title: Understanding Signals
• Contents: Guide to Generate, View and Measure Wave Forms
• Product: Microcontroller Accessories
• Lead Free Status / RoHS Status: Not applicable / Not applicable
• Other names: 70009PAR

The pulse train generated by pressing 5 on the remote control is shown in Figure 7-11.
You can see that the 10-bit wide data is transmitted LSB (least significant bit) first.
You should see the same data in your Debug Terminal (Figure 7-12). The program first
looks for the start pulse then counts the 10 pulses for each bit. The value of each bit is
listed.
From this we can demodulate the value of the data transmitted. The last four bits don’t
change so they are omitted. What we are left with is an 8-bit value of the demodulated
signal. You could use this to instruct the BASIC Stamp to do different tasks by the
remote control, or to send data between two BASIC Stamps.
Figure 7-12:
Decoding
keypress 5 on
a Sony
remote