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Issue #208 November 2007
Analog Techniques
NimbleSig
A Compact DDS RF Signal Generator
by Thomas Alldread
Second Prize Luminary Micro DesignStellaris2006 Contest
Start | Design & Hardware | Assembly | Firmware | Calibration | Operating Procedure | Project Complete | Sources & PDF
| Command | Function | Command | Function |
| AF1..1000000 | Set amplitude scale factor | MA | AM modulation on |
| B0 | Set RF out level to maximum | MD1..100000 | FM peak deviation Hz |
| B1 | Set level to (max. 10 dB) | MF | FM modulation on |
| B2 | Set level to (max. 20 dB) | MP1..99 | AM modulation depth % |
| B3 | Set level to (max. 30 dB) | MQ1..20000 | Modulation frequency Hz |
| B4 | Set level to (max. 40 dB) | MX | Modulation off |
| B5 | Turn RF output off | R1 | Read & disp. CFR1 in hexidec. |
| C1 0..31 | Clear bit in CFR1 register | R2 | Read & disp. CFR2 in hexidec. |
| C2 0..23 | Clear bit in CFR1 register | RA | Read & disp. amp scale factor |
| FH1..192000000 | Freq = # hertz at 10 dBm | RP | Read & disp. PhaseOffset mDeg. |
| FK1..192000 | Freq = # hertz at 10 dBm | RW | Read & disp. freq. tune word |
| FM1..192 | Freq = # hertz at 10 dBm | S1 0..31 | Set bit 00..31 in CFR1 register |
| H1 | Display help screen 1 | S2 0..23 | Set bit 00..23 in CFR2 register |
| H2 | Display help screen 1 | SP0..360000 | Set phase offset to millidegrees |
| L | Measure RF input level | Z | MPU deep sleep-wake any key |
| Table 1The NimbleSig commands are all in standard ASCII, 115 kbps, and 8N1 with no flow control. Frequencies may be abbreviated in megahertz, kilohertz, or entered directly in hertz. For example, 100 kHz can be entered as FK100<Enter>. ASF is in mfactors to obtain maximum output send AF1000000<Enter>, or to obtain 50% of maximum voltage level send AF500000<Enter>. Similarly, phase offset is set in millidegrees. | |||
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