VDrive2 .ROM upgrade cable

BCJKiwi

Senior Member
VDrive2 - ROM upgrade cable

Reprising lost post.

FTDI has confirmed VDrive2 fw v3.54 has a bug that prevents update from the USB device and requires updating via the vprog_com.exe program using a level shifting cable to ensure that only 3.3V is applied to the UART (Despite the UART being happy with 5V from the PICAXE in normal operation).

Have reviewed historical posts by Tarzan and Therowes (Archive #23).

@Tarzan
The Max232 datasheet indicates it will output at 7V so would not have thought use of this would be safe or are you implementing some additional techniques to reduce the voltage?

@Therowes
Have built a cable using a 74LS04 with
Tx PC -> 1/6 74LS04 -> Rx VDrive2 UART
and
Tx -> VDrive2 UART -> 1/6 74LS04 -> Rx PC
5V supplied to VDrive2 and 74LS04 and common 0V for all including download cable.
Unused 1/6ths of 74LS04 tied either low or high.
PC COM1 set at 115200,n,8,1
Jumpers on VDrive2 set for bootloader and serial uart.
CTS on VDrive2 UART tied low.

When attempting to download the VProg program simply reports an initialisation error.

Any further suggestions/advice gratefully received.
Thanks
 
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Technical

Technical Support
Staff member
All your SPI experimetation needs recognition - PM us with your postal address and we will send you a new VDRIVE2!
 

tarzan

Senior Member
MAX232

I could be wrong but +5V powered MAX232 should only output 5V on TTL/CMOS OUTPUTS legs 9,12 R1OUT & R2OUT. If you use MAX3232 @ 3V3 they should only output 3V3. You could add 1K resistor between R1OUT or R2OUT and VDrive2.

Remember it’s PC Tx to MAX232 R1IN via MAX232 R1OUT to Rx VDrive and VDrive Tx to MAX232 T1IN via MAX232 T1OUT to PC Rx.

There is also a jumper under the cover of VMusic2 that needs to be put into the program position, probably the same for VDrive2.
 

tarzan

Senior Member
Vinculum Release Notes

Vinculum Firmware V03.58 30-September-2007

Release Notes

Known Issues:

All Firmwares reflasher process. There may be issues using reflasher files if a reflasher file for V03.55, V03.54 and V03.51 has been used. Please contact technical support if the reflasher procedure fails. Customers using supplied ROM files in the VPROG programming application are unaffected.
 

BCJKiwi

Senior Member
@Technical
Well that is very much appreciated.
I have a long history in mechanical engineering and computing (shows my age I guess).
The spirit of selfless sharing and co-operation as well as tolerance for newcomers shown by the members of this forum hearkens back to the true spirit of the early days of computing and the internet and is one of the factors that attracted me to PICAXE.
 

BCJKiwi

Senior Member
@Tarzan
I was aware of the reflasher issue - see my first post - It just took FTDI weeks and a couple of prompts to confirm what was required.

The jumpers were set correctly - also see my first post.

The MAX232 data sheet I have shows;
VOH High-level output voltage T1OUT, T2OUT Min 5v Typical 7V
VOL Low-level output voltage T1OUT, T2OUT Typical -7 Max -5 V
on a 5V supply.
It also indicates in the main feature table that the Voltage output could swing to +15v and -15V
- hence my concerns.

The other thing of interest is that the VDrive2 Circuit diagram shows all the connections on the interface except the 5V supply are tied to the onboard 3V3 regulator output via 47k resistors.
 

tarzan

Senior Member
T1OUT or T2OUT would be connected to your PC RS232 port and is designed to cope with -15 ~ +15 volts.
 

tarzan

Senior Member
I just had another look at the setup that I was using and realized that I have the full setup with CTS & RTS on VMusic2 connected also. Some times you can loop these on the PC side.

So it’s PC Tx to MAX232 R1IN via MAX232 R1OUT to Rx VDrive and VDrive Tx to MAX232 T1IN via MAX232 T1OUT to PC Rx.
&
PC RTS to MAX232 R2IN via MAX232 R2OUT to CTS VDrive and VDrive RTS to MAX232 T2IN via MAX232 T2OUT to PC CTS.
 

BCJKiwi

Senior Member
Thanks Tarzan.

Have a couple of Max232 on hand but have not yet built a circuit using them - one of my future steps which it looks like I need to bring forward.

Just studying the max232 data more closely along with your post #3 to see exactly how to hook this up since the 74LS04 does not seem to work for me.

R1Out should max out at 3.5V which is fine for VDrive2
T1Out to the PC will be 5-7V with a 5V supply on VS, or higher if Vs is higher,
so your recommendations are spot on.

I could not see any reference to the unused second port in the data sheet - I presume it is Ok to leave these T2/R2 port pins floating.

Thanks for persisting with this thread for me.
Now to try and build enough of the circuit to try the download (have all the necessary caps etc).

Just picked up your post #8 - well that's one answer with what to do with the spare ports!
 
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hippy

Technical Support
Staff member
Have built a cable using a 74LS04 with
Tx PC -> 1/6 74LS04 -> Rx VDrive2 UART
and
Tx -> VDrive2 UART -> 1/6 74LS04 -> Rx PC
Did you include a current limiting resistor between the PC TX and 74LS04 input ?

The re-flashing documents aren't very clear to me on a first reading but it looks like you also need to handle the CTS and RTS lines at least, plus perhaps the PROG and RESET.
 

BCJKiwi

Senior Member
I have built a download cable using Tarzan's information and a max232.

It worked first time!

Thanks VERY much.

So to recap;
PC Tx --> MAX232 R1IN --> MAX232 R1OUT --> VDrive2 Rx
VDrive2 Tx --> MAX232 T1IN --> MAX232 T1OUT --> PC Rx.
&
PC RTS --> MAX232 R2IN --> MAX232 R2OUT --> VDrive2 CTS
VDrive2 RTS --> MAX232 T2IN --> MAX232 T2OUT --> PC CTS

PC Serial port set to 115200 Baud, n, 8, 1, Hardware flow control. These settings are required to match the built in settings of the bootloader in the VDrive2.

If I can sort out a simple circuit diag will post circuit plus photo etc in code snippets.
 
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andrew_qld

Senior Member
Well done BCJ! Also thanks to Tarzan. I'm planning on having a play with one of these in the near future so I have been watching this thread with great interest.

Cheers,
Andrew
 

hippy

Technical Support
Staff member
Oops : I seemed to have missed tarzan's post which detailed the MAX232 wiring. If you're willing to try it, it would be interesting to see if you can get a 74LSxx version which replaces the same. When I did the XBee flashing I used a 74HC00 powered off 3V3 and a 22K resistor for the PC TX.
 

BCJKiwi

Senior Member
You should only require this cable if you can't download the fw to the VDrive2/Vmusic2 by the USB port method due to a fw version with the download bug - i.e. V03.55, V03.54 and V03.51.
 

tarzan

Senior Member
That’s good to hear and know that you weren’t permanently locked out from downloading the latest updates.
 

BCJKiwi

Senior Member
Have posted the details of this cable build and fw updating process in the 'User projects - Miscellaneous' section.

Thanks again to all for your assistance.
 

sevs3

Member
Congratulations BCJKiwi. I will be very interested to hear how you go with working with SPI now. Are there any changes that you are aware of to help with SPI work?

I havnt been able to work on the code much at all, between not being at home and working :(

I might have to email Vinculum and get the update aswell, seeing that it isnt actually that hard to update by making your own calbe.
 

BCJKiwi

Senior Member
I've not had much chance to do more programming work either but it's high on my list.

You won't need to email Vinculum as the files are available for download from their website - see the post in the 'User projects - Miscellaneous' section.

If you need to update via the cable you will need the .ROM file for your device type (carefully read the text at the top which tells you which file you need for which device) and the vprog_com file. Follow the instructions in the 'User projects - Miscellaneous' section.
 
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