I have a kit with and CP2102 from ebay (http://www.ebay.com/itm/131070418525) will that fry my emonTX V3 if I connect it on the UART port?
I can't figure out if the CP2102 is 3v3 or not (or if emonTX V3 can handle 5V on the UART port).
What is the alternative to change FW on the TX (I do have an raspberry PI).
Re: Will CP2102 fry my emonTX V3
Useful information for yours does seem to be scarce, but it does say "5 V" in the page title. You can buy one that is guaranteed not to damage your emonTx here, and that one provides both 3.3 V and 5 V. If you get the emonTx schematic from Solderpad, you can check how the socket connections relate to the on-board voltage regulator.
Re: Will CP2102 fry my emonTX V3
Hi Fredike,
It will not fry your emonTX. but I had some problems with the pin-out from that cheap cp2102 adapter. see my post: http://www.bluemotica.nl/index.php/en/arduino/arduino-faulty-ftdi-adapter
The Amega 328 is 3.3 and 5 Volt compliant on the ports so that's ok. and the emontx has an range from 3.3 to 6 volt.
http://wiki.openenergymonitor.org/index.php?title=EmonTH
Re: Will CP2102 fry my emonTX V3
"The Amega 328 is 3.3 and 5 Volt compliant on the ports so that's ok"
I'm not sure that's strictly true is it? The part can run at 3.3V or 5V, but having chosen a Vcc, the maximum input voltage on any pin is Vcc + 0.5V. So for instance, if you were running your ATmega at 3.3V, the highest voltage you could apply to a pin would be 3.8V.
I know nothing about emontxs, and what voltages they run at, so I'm not questioning that aspect of your reply.
Re: Will CP2102 fry my emonTX V3
dBC your right.
I digged a little on the Rf328u module and found:
http://shop.ciseco.co.uk/rf-328-bare-arduino-atmega-328-compatible-micro...
So pin 1 on the board has 3.3 volt with an max of 3.9 volt. the FTDI adapter provide also 3.3 volt so just connect the right ports to the arduino.
see my post on bluemotica.nl:
Re: Will CP2102 fry my emonTX V3
I'd just like to point out that the pinout in your photo, Alco, is different to the Wicked Devices one sold in the shop, and cannot be used without an adapter cable (specifically, GND and RST are transposed).
Incidentally, I think RST should be RTS - Request To Send, and DTR should be Data Terminal Ready; these names being a carry-over from the signals used for RS232 serial communications.
Re: Will CP2102 fry my emonTX V3
I think the RST pin on these devices is actually a reset to the processor chip.
On my devices, there are separate RTS/CTS pins
Geoff
Re: Will CP2102 fry my emonTX V3
Your damm right that it's a reset (usb) chip pin and not the reset for the arduino (DST). so yes you have to make an adapter cable to get the right pins. that's what I wrote on my article at bluemotica.nl
It was really a pain tot get that clear when I used the CP2102 pcb for the first time..
Re: Will CP2102 fry my emonTX V3
For anyone who is interested, this is the shop CP2102: