Difference between revisions of "STM32 Oscilloscope"
From ScienceZero
(→Coding) |
(→Limits) |
||
Line 103: | Line 103: | ||
==Coding== | ==Coding== | ||
===Limits=== | ===Limits=== | ||
− | *The A/D | + | *The three A/D converters are 12 bits |
− | + | :Maximum guaranteed clock frequency is 14 MHz, giving 1 MHz sample rate | |
− | + | :Maximum possible with a 8 MHz crystal is 12 MHz | |
− | + | :Two ADCs can be run in interleave for (12 / 14) * 2 = 1.74 MHz (highest guaranteed sample rate) | |
− | + | :Maximum ADC clock rate at 72 MHz system clock is 36 MHz giving (12 / 14) * 2 = 5.14 MHz | |
− | + | :Maximum system clock is 128 MHz giving a theoretical maximum of 9.14 MHz by overclocking everything | |
+ | *System memory is 64 KB | ||
===Protocol=== | ===Protocol=== |
Revision as of 20:57, 11 May 2010
Contents
- 1 Features
- 1.1 Vertical (Voltage/Frequency)
- 1.2 Horizontal (Time)
- 1.3 Trigger
- 1.4 Auto Scale
- 1.5 Metered values
- 1.6 Markers
- 1.7 Data output
- 1.8 Display modes
- 1.9 Dynamically labelled grid
- 1.10 Pause and scroll back
- 1.11 Protocol decoding
- 1.12 DSP
- 1.13 Log playback
- 1.14 Output and control interfaces
- 1.15 Logic analyzer
- 1.16 Component value testing
- 2 Coding
- 3 Advanced features for the future
Features
Vertical (Voltage/Frequency)
- V/Div
- AC/DC
- Offset
- Invert
- Probe divider / multiplier
Horizontal (Time)
- T/Div
- Offset
Trigger
- Voltage level trigger
- Trigger on rising / falling edge
- Single trigger / force trigger / trigger continiously
- Auto detect and track trigger level
- Trigger at fixed frequency / Trigger output
- External trigger
- Pretrigger (sample continiously then stop n samples after the trigger)
- Filtered trigger (low frequency / high frequency / number of pulses)
- Video trigger
- RS-232 trigger
Auto Scale
- Voltage
- Period
Metered values
- Voltage
- True RMS
- Average
- Peak
- Peak to peak
- Frequency
- Duty
Markers
- Voltage
- t1
- t2
- delta t
- frequency
Data output
- Save display snapshot to picture
- Save display frames for movie
- Save wave data to file (raw / .CSV)
- Stream non interrupted wave data to file
Display modes
- Waveform
- range (old oscilloscope method)
- Average per sample
- Average per waveform
- XYZ
- Fourier transform
- Spectrum
- Average spectrum
- Subtract average
- Spectrogram
- Turtle - Channel A = speed, Channel B = direction
- TV (pixel brightness)
- Histogram
- Roll mode (continuous scrolling)
- BPM mode for heart rate monitoring
- wide range of scroll rates
- dynamically zoom in to check on activity of extremely slow rates
Dynamically labelled grid
Pause and scroll back
Protocol decoding
- RS-232
- TTL RS-232
- IR remotes
- I2C
- SPI
DSP
- Pre-scale before process
- Add channels
- Subtract channels
- Multiply channels
- AM demod
- FM demod
- Configurable bandpass filtering
- Phase tracking hum removal
- Audio output
Log playback
Output and control interfaces
- Computer via RS232
- Computer via Wireless RS232
- LCD touch screen
- Computer via USB
Logic analyzer
- Multichannel
Component value testing
Coding
Limits
- The three A/D converters are 12 bits
- Maximum guaranteed clock frequency is 14 MHz, giving 1 MHz sample rate
- Maximum possible with a 8 MHz crystal is 12 MHz
- Two ADCs can be run in interleave for (12 / 14) * 2 = 1.74 MHz (highest guaranteed sample rate)
- Maximum ADC clock rate at 72 MHz system clock is 36 MHz giving (12 / 14) * 2 = 5.14 MHz
- Maximum system clock is 128 MHz giving a theoretical maximum of 9.14 MHz by overclocking everything
- System memory is 64 KB
Protocol
One byte each: C SS DDD... C = Code S = Size D = Data
Commands PC → STM32
- 0 0 4 DDDD - Set sample rate in Hz
- 1 0 5 D DDDD - Trigger mode & voltage
- 2 0 1 D - Input type 0=DC, 1=AC, 3=frequency
- 3 0 4 DD.DD - Input gain
- 4 0 1 D - Number of channels
- 5 0 2 DD - Set pin state of a 16 pin port
- 6 0 0 - Reset
- 7 0 4 AAAA - Read data from address
- 8 0 8 AAAA DDDD - Write data to address
- 9 0 4 AAAA - Execute address
Commands STM32 → PC
- 0 SS HL HL... - Sample data, 8 bit unsigned, H = highest value during the sample period, L = lowest value during the sample period
- 1 SS DD DD... - Sample data, 16 bit per sample
- 2 SS DD DD... - Pin state from one 16 pin port
- 3 0 4 DDDD - Return data from address
Advanced features for the future
- Realtime view and control over IP by another computer
- iPad/IPhone view and control
- Web interface