Frequency Sweep (LC_count)

Setup

• SCuM

  • Turn on LC divider, change radio to RxEnable state, configure to one frequency setting

  • Setup a periodic timer with RFTimer for 1ms, when the timer interrupt fired:

    • read the LC div counter and store in a buffer

    • when the buffer is full (10 sample points), calculate the average value and print out along with the current frequency setting, then clear the buffer and update to another frequency setting

  • Conduct the same experiment but setting radio to TxEnable state

Experiment duration

Each experiment lasts for 1*10*32*32*32 = 327.680 seconds

• 1: 1ms interval to read the LC div counter

• 10: 10 LC div counter reads (sample point)

• 32*32*32: number of frequency settings

The experiment is conducted twice: one when radio is set to RxEnable state, one is set to TxEnable.

Result

16 plots (one for Rx setting, one for Tx setting), where:

• Y: LC frequency (translated from LC_count)

• X: frequency settings (from 00.00.00 to 31.31.31)

Open

Open

Raw data

The JSON file contains the LC_count for both Q3 and Q8 boards at TX and RX states.

Open

Frequency Sweep (SCuM → OpenMote)

Setup

• OpenMote

  • listens on one channel, all the time.

  • Prints out the payload of any packet it receives and the frequency offset reader from FREQEST register.

• SCuM:

  • Sends 3 frames at each frequency settings [coarse,mid,fine]

  • A frame is sent every 5 ms

  • The frame payload contains test.xx.yy.zz, where xx.yy.zz indicates “coarse.middle.fine”

Experiment duration

For each channel, the experiment lasts for 3*5*32*32*32 = 491.520 seconds

• 3: 3 frames each frequency settings

• 5: 5 ms sending interval

• 32*32*32: number of frequency settings

The experiment is repeated 16 times on different channels.

Result

16 scatter figures (one figure per channel), where:

• Y: frequency offset (read value of FREQEST register)

• X: frequency settings (from 00.00.00 to 31.31.31)

Raw data

The freq_sweep_tx_result.json files contain the frequency settings and freq_offset of each received frames.

Frequency Sweep (OpenMote → SCuM)

Setup

• SCuM

  • Listens on one frequency setting for 15ms, then changes to another frequency setting.

  • Prints out the frequency setting when a valid frame is received.

• OpenMote:

  • Constantly send one frame every 7.5ms on one channel

Experiment duration

For each channel, the experiment lasts for 15*32*32*32 = 491.520 seconds

• 15: 15ms duration to listen on one frequency setting

• 32*32*32: number of frequency settings

The experiment is repeated 16 times on different channels.

Result

16 histogram figures (one figure per channel), where:

• Y: number of pkt received

• X: frequency settings (from 00.00.00 to 31.31.31)

Raw data

The freq_sweep_rx_result.json files contain the frequency setting of each received frames.

Frequency Sweep when LC divider is on or off

Setup

• Using the same code running for Frequency Sweep experiment above but under conditions when LC divider is turned on and turned off.

Experiment

• The experiment runs one time for channel 11, 18 and 26 respectively

Result

Frequency Sweep (SCuM → OpenMote)

6 histogram figures (one figure per channel), where:

• Y: frequency offset (read value of FREQEST register)

• X: frequency settings (from 22.00.00 to 29.31.31)

Divider off

Divider on

Divider off

Divider on

Divider off

Divider on

Frequency Sweep (SCuM ← OpenMote)

6 histogram figures (one figure per channel), where:

• Y: number of pkt received

• X: frequency settings (from 22.00.00 to 29.31.31)

Divider off

Divider on

Divider off

Divider on

Divider off

Divider on

Raw data

Serial output data

The zip file contains the serial output from OpenMote, and SCuM during conducting the frequency sweep tests. The raw data provided above are derived from those serial output and formatted in JSON through scripts. So you should not required to use those serial output information data. Just stored here in case.

freq_sweep_lc_count.zip contains the lc_count test serial output of both q3 and q8 board.

freq_sweep_q8.zip contains the Q8’s freq_sweep test serial output for both TX and Rx.

freq_sweep_q3.zip contains the Q3’s freq_sweep test serial output for both TX and Rx.