Simple but usefull 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.
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
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.
2009.10.18 Some changes to read/write queue scheme.
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.
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.