miniscope v2
Simple but useful miniature digital storage oscilloscope with USB interface. Additional data logger mode for long-term measuring. Based on AT91SAM7S64 microcontroller.
- interface: USB,
- power supply: USB,
- driver used: libusb, there are drivers available for both 32- and 64-bit OS,
- sampling frequency: up to 500ksps,
- 8 bits/sample,
- data buffer size: 14kB (using v2a firmware v2a: real-time data streaming, recording CONTINUOUS data stream up to billion (1e9) samples),
- trigger modes: rising and falling edge with user defined threshold level (firmware v2a: triggers defined in PC software),
- sensitivity: 6 ranges changing like 1:3, up to 3,3V/div (+/-16,5V),
- integrated dc/dc converter, positive and negative voltage measuring,
- low-speed datalogger mode with data averaging,
- data export: CSV, JSON, bitmaps, custom format,
- simple enough to be built without using another oscilloscope (no chicken-egg problem),
- BOM: ~$20.
Software and communication protocol are based on previous two DSO projects.
Electric scheme
Brief documentation (updated with sources): armscope doxygen
Firmware version 20090613 (7-zip 114 kB)
armscope_dll_0_0_7.7z - input DLL for miniscope v3 application
armscope_dll_0_0_8.7z - input DLL for miniscope v3 application, version 0.0.8 with sensitivity calibration
armscope_dll_0_0_9.7z - increased receive buffer size
2009.09.21 New ARM firmware and device library - increased maximum sampling frequency from 300 kSps to 500 kSps. Receiving buffer size for dll set to 512 B.
Firmware 20090921, compiled with WinARM 20070505
armscope_dll_0_0_10.7z
2009.09.23 Added C29 1nF near ADC input of microcontroller - output noise was greatly reduced. D'oh!
Electric scheme 2009.09.23
2009.10.12 Little improvement to speed of fetching data from device. Added 500Hz sampling setting.
armscope_dll_0_0_11.7z
2009.10.18 Some changes to read/write queue scheme.
armscope_dll_0_0_12.7z
2010.03.11 Added alternative firmware + dll set working with this hardware - miniscope v2a.
2010.03.19 Probably first (not counting my prototype) device based on miniscope v2, photo sent by Jakub Niziołek. Circuit was splitted into two boards: analog and digital part. Analog part is slightly simplified (no sensitivity and coupling type selection).
2010.04.18 Corrected inaccurate sampling period reported to GUI application (mostly when selected highest sampling frequency - almost 2% error). Similar fix applied to miniscope v2a library.
armscope_dll_0_0_13.7z
2010.04.22 Added some description of armscope v2 scheme.
2011.06.22 Miniscope v2 turns obsolete. New hardware project (eagle) is moved to miniscope v2b page.
