This is the way it is implemented today, but it may be possible to use the ARM DAC (digital to analog converter) to generate more complex waveforms. I haven’t looked at the DAC capabilities of the DSO Nano processor specifically, but generally this approach is used to synthesize just about any waveform, including replay of pre-recorded samples. Input to the DAC is typically by DMA (Direct memory Access) from either RAM or FLASH.
Ah …, we don’t want that – I’ll provide an update (APP 3.02) to fix this.
The new approach to sampling makes the Nano useful also for a crude view of RS-232/RS-485 and even I2C and SPI at moderate frequencies. The Nano can also supplement a protocol analyzer in that we can see the shape of digital pulses to determine if we have issues with decoupling, floating grounds, transients etc. To make a good digital protocol analyzer however we would need an additional connector for general purpose I/O (e.g. 8 channels).
In the thread on V2.5x I wrote a brief guide on how to use the firmware and you may want to read this.
“No File” suggests that the card is present and we have successfully read the FAT table. Next step is to locate the directory entry and this where it fails. That is, the requested file was not found or some other error occurred. Some early Nano’s had hardware issues with SD cards (search the forum for more input on this) and if this applies to you, further testing may not help. As a general guide however, these are the steps that work for me:
Format the SD card in the DSO Nano with either FAT16 or FAT32 (not NTFS)
Download the file “DSO Files.zip” from the first post in this thread and then extract and copy the files to your card
Select menu option “FI” and sub option “Save Img”
Make sure you select (left/right key) a file that actually exists (e.g. S 0001.BMP)
Press B (or long M) to save
If successful, the info field will advance to “S002.BMP” and you should be able to open and view the screen capture bitmap file on your host computer
I’m using my DSO Nano (first generation) with Windows XP and have tried with FAT16, FAT32 and also a blank OEM formatted card (2GB SanDisk)
I don’t have access to a V2, but I didn’t expect it to make a difference in this respect.
Are you able to format and read/write from/to the CD card while the card is inserted in the DSO Nano? What about the other file functions? Can you save/load reference files or save/load profiles?
Unfortunately a number of physical changes would need to be implemented to allow this to happen that would require a rework of the pcb
1 the fout pin is currently passed through a digital buffer
2 the processor would need to be replaced with a higher spec device (perhaps with library ramifications)
3 the fout pin is not one of the DAC pins on the processor as these pins are being used for the keyboard at the moment
Im new to the Nano and these forums. Sorry if my q’s are somewhat green. I just rec’d a Nano V2 and have a few questions:
will this firmware work for V2
do I need a micro SD card in the unit for it to work (or is just for related features of the software).
when using the upgrade tool it mentions that it has to be done for the App and DFU file. Do you simply run through the flash procedure the same way 2x’s - just selecting each file through each iteration? If so, which one is done first? (the PDF guide published is not clear on this).
Thanks @Tormod. Flashing went find. The new firmware is much more intuitive. Thx @BenF. Now I just need to find a supported microsd card. Anyone buy/know of any of the ones on dealextreme.com that support SPI mode? Their specs dont say.
One more thing you could try is to download and run “sdformatter” (search with google). This is a utility program you can use to completely re-initialize and format your SD card (remember to copy the sample files onto the card after format).
I’m having almost the same issue. With the probe connected, or not; when turning on the DSO, it quickly goes -40mV, then stays on -80mV seemingly forever. I don’t recall the original firmware doing this. Will have to check…
Your firmware is great! I am looking for one function only: how to calibrate the scope and how to stor the settings for next switch on?
My hardware is not calibrated: it shows 4Vpp squarewave generated from 3.7V battery…
What was the point of rewriting the library if the source code is unreleased for general usage as it does nothing to help any other developer either as a learning aid or to enable further development.
Perhaps Seeed should pay BenF and acquire the source code so that the Nano can truly become open source.
If Seeed would have GPL-licensed their original open-source code, we would not had all these different closed-source derivatives… Of course, for many end-users, a nicely working closed binary is more important than having the source code. But over time, I think open-source (with proper copyright and licensing) pays off for everybody.
EDIT: I checked the source code, and it is copyrighted to e-Design Co.,Ltd. I do not know if they anywhere have allowed other people to copy, modify it and redistribute (binary or source) derivative works.
EDIT2: There is a MIT license on code.google.com/p/dsonano/ so if the code is taken from there I guess it is licensed under those conditions. You basically have to distribute the license together with your version of the software.
No one can really check if he has written the version from scratch because it is still unreleased (he says he did, but that is only his word). One think you can check is the fact that he uses his own copyright (it is displayed all over when you start up). Probably he also put his copyright on a lot of Seed’s open source work which isn’t very nice to begin with.
Regardless of whether we like it or not the licence gives him the right to keep a private branch. One thing is certain however: writing less than nice things about his work is not going to help.
I for one would be really happy if he releases it in some form or another but in the meantime I am extremely happy for all his enhancements!
Licensing and copyright are not straight forward topics. Give BenF time to sort it out. If I were BenF, I would publish the source code under a license so that other people can not distribute closed-source derivatives of it, but are forced to publish their enhanced code. But the one who writes the code is the one to decide! On the other hand it would be good if he would be clear about it if he does not intend to publish the code, so that we can move on.
I read somewhere that the ARM that the DSO Nano runs on has a dual fast interleaved mode, that could ramp up the 1Ms/s to 2Ms/s through the firmware. Has anyone else read this or experienced anything regarding this dual fast interleaved mode, or any implementation thereof?
