Difference between revisions of "SainSmart DDS120"

From sigrok
Jump to navigation Jump to search
(Move vendor protocol info, cleanup firmware info.)
(→‎Firmware: Mention that Zadig needs to be run twice.)
 
(6 intermediate revisions by the same user not shown)
Line 1: Line 1:
[[File:Dds120 mugshot.png|thumb|right|SainSmart DDS120]]
{{Infobox oscilloscope
| image              = [[File:Dds120 mugshot.png|180px]]
| name                = SainSmart DDS120
| status              = supported
| source_code_dir    = hantek-6xxx
| channels            = 2
| samplerate          = 50MHz
| samplerate_equiv    =
| bandwidth          = 20MHz
| vertical_resolution = 8bit
| triggers            = none (SW-only)
| input_impedance    = 1MΩ‖25pF
| memory              = none
| display            = none
| connectivity        = USB
| features            =
| website            = [http://www.sainsmart.com/sainsmart-dds-120-20m-50m-s-virtual-oscilloscope-silver.html sainsmart.com]
}}


The [http://www.sainsmart.com/sainsmart-dds-120-20m-50m-s-virtual-oscilloscope-silver.html SainSmart DDS120] is a USB-based, 2-channel oscilloscope with an analog bandwidth of 20MS/s and 48MS/s sampling rate.
The '''SainSmart DDS120''' is a USB-based, 2-channel oscilloscope with an analog bandwidth of 20MS/s and 50MS/s sampling rate.


This device appears to be a rebadge of the [[Rocktech BM102]] (or vice versa). The [[SainSmart DDS120/Info|lsusb]] is exactly the same, the PCB is exactly the same (both have a "656517" and "102LJT1402" silkscreen), and the components used appear to be the same as well.
This device appears to be a rebadge of the [[Rocktech BM102]] (or vice versa). The [[SainSmart DDS120/Info|lsusb]] is exactly the same, the PCB is exactly the same (both have a "656517" and "102LJT1402" silkscreen), and the components used appear to be the same as well.
Line 62: Line 79:
== Protocol ==
== Protocol ==


We use an open-source firmware that is part of [[fx2lafw|sigrok-firmware-fx2lafw]] for this device (i.e., not the vendor firmware/protocol), hence we do not need to know the vendor protocol.
We use an open-source firmware for this device (i.e., not the vendor firmware/protocol), hence we do not need to know the vendor protocol. There is some [[SainSmart_DDS120/Info#Vendor_firmware|historic vendor firmware/protocol info]] for those interested, though.
 
There is some [[SainSmart_DDS120/Info#Vendor_firmware|historic vendor firmware/protocol info]] for those interested, though.


== Firmware ==
== Firmware ==


The vendor firmware is contained on the I²C EEPROM. The FX2 boots directly into that firmware. However, we replace it (only in RAM, the EEPROM is never modified) with an open-source firmware that is part of [[fx2lafw|sigrok-firmware-fx2lafw]] when the device is attached to USB.
In order to use this device, the [[fx2lafw|sigrok-firmware-fx2lafw]] (>= 0.1.4) firmware is required.
 
The open source firmware is currently missing the following planned features:
 
* <1MHz, 2, 3, 5, 6, 7.5, 9.6, 10, 15, 24, 30 MHz sampling rate support
* Turn on/off the calibration pulse
* Change frequency of the calibration pulse (add 10kHz, 100kHz and 1MHz)
 
==== Gain stage ====
 
The gain stage is 2 stage approach. -6dB and -20dB on the first stage (attentuator). The second stage is then doing the gain by 3 different resistor values switched into the feedback loop. The following does not correlate with measure on real hardware, there is a 6th gain position that is working though. It is very similar to another gain and was most likely omitted because of that.
 
<small>
# Channel 0:
PC1=1; PC2=0; PC3= 0 -> Gain x0.1 = -20dB -> 0x02 (1V)
PC1=1; PC2=0; PC3= 1 -> Gain x0.2 = -14dB -> 0x0A (0.5V)
PC1=1; PC2=1; PC3= 0 -> Gain x0.4 =  -8dB -> 0x06 (0.250V)
PC1=0; PC2=0; PC3= 0 -> Gain x0.5 =  -6dB -> 0x00 (0.200V)
PC1=0; PC2=0; PC3= 1 -> Gain x1  =  0dB -> 0x08 (0.100V)
PC1=0; PC2=1; PC3= 0 -> Gain x2  =  +6dB -> 0x04 (0.050V)
# Channel 1:
PE1=1; PC4=0; PC5= 0 -> Gain x0.1 = -20dB -> 0x02 (1V)
PE1=1; PC4=0; PC5= 1 -> Gain x0.2 = -14dB -> 0x22 (0.5V)
PE1=1; PC4=1; PC5= 0 -> Gain x0.4 =  -8dB -> 0x12 (0.250V)
PE1=0; PC4=0; PC5= 0 -> Gain x0.5 =  -6dB -> 0x00 (0.200V)
PE1=0; PC4=0; PC5= 1 -> Gain x1  =  0dB -> 0x20 (0.100V)
PE1=0; PC4=1; PC5= 0 -> Gain x2  =  +6dB -> 0x10 (0.050V)
</small>
 
==== AC/DC coupling ====


The coupling is controlled via 2 PhotoMOS chips.
The firmware was originally written by Jochen Hoenicke (see [http://sigrok.org/gitweb/?p=sigrok-firmware-fx2lafw.git;a=blob;f=README README] for details), thanks a lot!


<small>
'''Note''': The firmware is '''not''' flashed into the device permanently! You only need to make it available in the usual place where [[libsigrok]] looks for firmware files, it will be used automatically (and "uploaded" to the Cypress FX2's SRAM every time you attach the device to a USB port).
# Channel 0:
PE3=0 Disable AC-coupling capacitor (DC-coupling)
PE3=1 Enable AC-coupling capacitor
# Channel 1:
PE0=0 Disable AC-coupling capacitor (DC-coupling)
PE0=1 Enable AC-coupling capacitor
</small>


==== 1kHz calibration square wave ====
'''Note''': On Windows, you will have to [[Windows#Device_specific_USB_driver|assign the WinUSB driver via Zadig]] '''twice''': the first time for the initial USB VID/PID the device has when attaching it via USB (04b4:602a or 04b5:602a, depending on which vendor driver is currently being used by the device), and a second time after the firmware has been uploaded to the device and the device has "renumerated" with a different VID/PID pair (1d50:608e).


Pin PE2 controls the frequency of the calibration output on the PCB. It is driven by an ISR timer from the 8051 core of the FX2 chip.
See [[SainSmart_DDS120/Info#Open-source_firmware_details|this section]] for technical details about the firmware/hardware.


== Resources ==
== Resources ==
Line 121: Line 98:
* [http://www.360customs.de/en/2014/10/usb-oszilloskop-sainsmart-dds120-2-kanal-20mhz-50msps-buudairocktech-bm102/ Detailed description of the hardware]
* [http://www.360customs.de/en/2014/10/usb-oszilloskop-sainsmart-dds120-2-kanal-20mhz-50msps-buudairocktech-bm102/ Detailed description of the hardware]
* [http://www.sainsmart.com/sainsmart-dds-120-20m-50m-s-virtual-oscilloscope-silver.html Vendor product page]
* [http://www.sainsmart.com/sainsmart-dds-120-20m-50m-s-virtual-oscilloscope-silver.html Vendor product page]
* [https://www.eevblog.com/forum/testgear/saintsmart-dds120-software-download/msg818124/#msg818124 Vendor software download links]


[[Category:Device]]
[[Category:Device]]
[[Category:Oscilloscope]]
[[Category:Oscilloscope]]
[[Category:Supported]]
[[Category:Supported]]

Latest revision as of 15:17, 2 October 2018

SainSmart DDS120
Dds120 mugshot.png
Status supported
Source code hantek-6xxx
Channels 2
Samplerate 50MHz
Analog bandwidth 20MHz
Vertical resolution 8bit
Triggers none (SW-only)
Input impedance 1MΩ‖25pF
Memory none
Display none
Connectivity USB
Website sainsmart.com

The SainSmart DDS120 is a USB-based, 2-channel oscilloscope with an analog bandwidth of 20MS/s and 50MS/s sampling rate.

This device appears to be a rebadge of the Rocktech BM102 (or vice versa). The lsusb is exactly the same, the PCB is exactly the same (both have a "656517" and "102LJT1402" silkscreen), and the components used appear to be the same as well.

The device was apparently created by someone named "buudai" in 2012 (also reflected in the lsusb and in the former buudai.com website).

See SainSmart DDS120/Info for more details (such as lsusb -v output) about the device.

Hardware

Or in newer hardware:

Photos

Teardown 1:

  • Device, top

  • PCB, front

  • PCB, front

  • PCB, front

  • PCB, front

  • PCB, front

  • PCB, front

  • PCB, back

  • PCB, back

  • Box

  • Box

  • Box

Teardown 2 (purchased 03/2016):

  • Sticker

  • Package contents

  • Device, top

  • Device, bottom

  • USB

  • Connectors

  • PCB, top

  • PCB, bottom

  • MXTronix MXT2088

  • Cypress FX2

  • Microchip 24LC64I

  • TI CD4052BM

  • AMS1117-3.3

  • Unknown IC

Protocol

We use an open-source firmware for this device (i.e., not the vendor firmware/protocol), hence we do not need to know the vendor protocol. There is some historic vendor firmware/protocol info for those interested, though.

Firmware

In order to use this device, the sigrok-firmware-fx2lafw (>= 0.1.4) firmware is required.

The firmware was originally written by Jochen Hoenicke (see README for details), thanks a lot!

Note: The firmware is not flashed into the device permanently! You only need to make it available in the usual place where libsigrok looks for firmware files, it will be used automatically (and "uploaded" to the Cypress FX2's SRAM every time you attach the device to a USB port).

Note: On Windows, you will have to assign the WinUSB driver via Zadig twice: the first time for the initial USB VID/PID the device has when attaching it via USB (04b4:602a or 04b5:602a, depending on which vendor driver is currently being used by the device), and a second time after the firmware has been uploaded to the device and the device has "renumerated" with a different VID/PID pair (1d50:608e).

See this section for technical details about the firmware/hardware.

Resources

Retrieved from "https://sigrok.org/w/index.php?title=SainSmart_DDS120&oldid=13748"