New kits - 13803/4K - F/W .050

[lmantuano]

G'day JYE Tech!

just noticed your announcement of the new version (H/W & F/W) of the kits. http://www.jyetech.com/Products/LcdScope/e138.php

From what I read, the good news for recent buyers of the "old" kit, is that the only change is the value of R11, eh, easy!

But then I read that we, with "old" 138s, can't upgrade to F/W .050... and even if we do the R11 value change, you still won't give us the code...

Can please somebody confirm that I'm interpreting your announcement correctly? If so, how do you propose to distribute new firmware for "old" 138s..?

Anybody else seen this?

Also, I recently asked a question about the reason/use of the USB connector, no answer so far, I'll ask again, what is the Mini-USB port for?

regards,

Luigi M

[amb]

Luigi,

I read the post and came to the same conclusion - if you have an older DSO138 you're stuck.

If I had one complaint with the unit it would have been the noise on the signal which they seem to have fixed so I'd really like to get hold of the new firmware.

I can sympathise to some extent with Jyetech - they do all the work and someone clones their kit. They should pursue the counterfeit makers though rather than disadvantage the genuine (earlier) end users.

Hopefully they'll find a way to service their earlier customers. I won't hold my breath though.


Andy

[davef]

So, by reducing the gain of U2C significantly and doing something in S/W (maybe ADC setup) they manage to reduce the noise artifacts considerably.

Seems something else has to suffer here, ie resolution or ?

[MorganFlint]

So, by reducing the gain of U2C significantly and doing something in S/W (maybe ADC setup) they manage to reduce the noise artifacts considerably.

Seems something else has to suffer here, ie resolution or ?

In fact, I think the gain wasn't reduced, but increased.

If my calculations aren't wrong, for the last stage (U2C) Vo=G*Vi+5*R9/R10=G*Vi+5/3, with G=1+R9(R10+R11)/R10R11.

So, G=2 if R11=1.5K and G=8 if R11=0,15K.

This makes sense, as if we assume noise is constant (as it would be the case, if it was due to crosstalk inside the MCU), then increasing the gain by a factor of 4 would divide the signal to noise ratio by the same amount.

And, also, would make better use of the ADC resolution. If we set SENS1 in the 10 mV/div position and SENS2 in the x1 position, the gain of the whole chain is equal to the last stage and, as the screen is 8 div dvi (+/- 40 mV), this means the output of U2C varies between 5/3+- 0,32 V (1,99-1,35 V) with gain=8 and only between 5/3 +- 0,08V (1,75-1,59 V) with gain=2.

Apparently, modifications in the firmware shouldn't be very complicated for somebody who knows C and the compiler for this MCU (unfortunately, not my case )

@Jye: Please, have mercy on those who bought the first version! (in my case, I bougt it at Banggood where apparently they sell the original one)

[davef]

MorganFlint,

You are correct. After I shut the computer down I thought I had got it wrong.

I had a look through board.c and couldn't spot what I was looking for. However, we use the STM32 series at work so I'll talk with the guru.

Also, bought mine from Banggood. There is one outfit (taibo?) selling the newer version and for the money I would just buy another one. Search for the firmware version.

[lmantuano]

Hey JYE...!
also bought mine from Banggood.. Please find a way to let us upgrade to the newest and future F/W versions..
thanx
Luigi

[jye1]

For customers who bought the earlier version and really want to change firmware to version -050 we plan to offer a special discounted kit that includes a programmed board and all other parts (without LCD and probe). Price is USD $18.00/each including worldwide shipping. This special kit will be available next week. Buyer needs to provide original purchase receipt and high resolution photo of his/her board.

[caulktel]

Will the printable Banggood invoice be suitible in PDF form? I don't recall ever getting a original purchase receipt.

Joel

[davef]

Which area of the board would it be most appropriate to photograph?

[jye1]

The front of main board without LCD module would be fine.