Open DSO-150

Fully open source firmware for JYETECH DSO-150 https://www.jyetech.com/Products/LcdScope/e150.php

Complete rewrite of DSO-150 Firmware

• No longer DSO-138 compatible (Sorry...)
• Rewritten for Atollic trueSTUDIO (Yea... Real debugging)
• Now using internal digital trigger through ADC IRQ (So trigger level can now be correlated to real voltage)
• Lots of new features like voltage overlay, markers, auto cal

Features

• Support 1 Analog and up to 3 Digital Channels
• Trigger on rising/falling/both edges
• Trigger on Analog, Digital 1,2,3 Signal
• Single/Norm/Auto Trigger Mode
• Exact trigger voltage
• Serial Data Dump
• Automatic Zero-Level Cal for all gain-stages
• Voltmeter mode (Averaged over last 10 samples)
• Signal Statistics Display
• Cursors for Analog Signal
• Load/Store Waveform to/from Flash
• Zoom Out Display (See more data with full sampling Rate)
• "Persistence" Mode
• Variable Signal Size for Digital Signal Waveforms
• "loop" mode to scroll current input-values
• AC/DC mode
• 3K Sampling Depth
• Buttons not blocked during sampling

Images

Features

Stats Display

Voltage Display

Zoom

Digital

Cursors

Key Assignment

• Encoder Left/Right -> Change Value

• Encoder Button Short Press -> Select next field -> (In Cursor Mode select next cursor) Long Press -> Activate Function -> A1 -> Enable Cursor Mode -> D1,D2,D3 -> Change Waveform Size -> Function -> Execute selected function -> Others -> Restore Defaults

• OK Button Short Press -> hold/run mode Long Press -> Show Analog Signal Stats

• Trigger Button Short Press -> Activate Trigger Level Long Press -> Enable/Disable Trace Persistence

• Sec/Div Button Short Press -> Select Time Base Selection

• V/Div Button Short Press -> Select Voltage Range Selection Long Press -> Enable/Disable Voltage Meter Mode

• Pressing V/Div,Sec/Div/Trigger while field is activated toggles through settings

• Hold OK button at power-up -> Reset all values to defaults

Cursor Mode

There are some limitations in cursor mode. While it is possible to use cursors both on signals in hold mode and running mode only the functions available via the buttons are available to modify. Short-Press on the encoder button returns back to cursor mode, long press on encoder-button disables cursor mode.

Loop Mode

In Loop mode samples will be added on the right side of the waveform. The buffer is limited to the width of the screen. (Works espcially well with voltage display enabled as voltmeter with history...)

AutoCal

The AutoCal function recalibrates the zero-point for all gain-settings automatically. Before triggering it make sure to set the coupling switch to GND and to disconnect any singal input. AutoCal data well be lost after restoring the default settings.

Digital Signals

Digital Signals can be connected to PB13/PB14/PB15. There's no protection on those ports so it better be max 3.3V logic level....

Building Open DSO-150

Open DSO-150 should build directly after opening the project in the free STM32 version of Atollic trueSTUDIO. https://atollic.com/truestudio/

It should also compile under the System Workbench for STM32 after creating a new project and importing the source files but I haven't tried that...

With an STLink V2 probe it is very easy to both program and debug the scope via the DebugWire Link. (I haven't tried uploading hex-files through the serial port with the STM32 Bootloader but there's no reason it shouldn't work...)

Libraries Used

The code for the graphics library is based on a heavily modified/optimized version of the Adafruit_GFX/Adafruit_TFT libraries.

TODO

• If somebody has a working example of using a STM32 timer to trigger the ADC and then have the ADC trigger an IRQ let me know.... Should work but I had no luck getting that to work...

References

• Adafruit Graphics Library - https://github.com/adafruit/Adafruit-GFX-Library
• Parallel 8 bit ILI9341 library - https://github.com/stevstrong/Adafruit_TFTLCD_8bit_STM32