P1 with FTDI not saving inversion

[hemant5400z]

Hi All,

Need some help with setting up FDTI. I have a FTDI i'm preparing to connect with my smartmeter so far so good.
The problem comes with inversion as I understand i need to invest the signal. When connected to Windows and using FTProg I can see the the device properly. VID 0x0403 PID 0x6001 Mafufacturer FTDI.

However when I invert the signal, it says ok and done but recycle or re-plug the device shows that it is not onverted so it is not saving the config. Does anyone know why and how to fix this?

The chip shows the folloowing:

FTDI
1750-c
CN480661
FT232RL


Any suggestions/help is appreciated.

Cheers,
Hemant

[erem]

this may be a cheap chinese knockoff, and not a true FTDI.
if that is the case, you can invert like this.

P1 Inverter with BC547.gif (9.67 KiB) Viewed 1710 times

[hemant5400z]

Thanks,

Where would I get the 3.3 from as the FTDI is set to 5V?

Assuming I can get GND from the FTDI, also I have put a 10K between 5v and RDX already.

Would a BC547C do?

Hemant

[erem]

a bc547c is fine.
if your ftdi is 5v tolerant on rx you can feed the bc547 with 5v.

[hemant5400z]

Hi Thanks rob,

just to check:

Q1 before 1k goes to RDX and Q1 after 1K goes to 5V split from FDTI

[erem]

not quite sure what you mean here

blue dot (5) connects with rj12 pin 5 of connector to meter
white dot to input of device connects with rx of ftdi adapter.

[hemant5400z]

yes correct and the 3.3v in my case connect to 5v on fdti.

Also would the 10k pullup still be required betwen vcc and RX?

[hemant5400z]

Mine is like in the attachment.

Any advice?

[erem]

looks good to me.
you can connect this and use a pc with a terminal emulator (win:putty or *nix:cu) to see if telegrams are sent by the p1 meter.

[hemant5400z]

Hi,

Thanks for all the help all is working and data is pulled into domoticz with this setup.

Cheers,
Hemant