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    I want to test a wifi module (ESP8266)

    Hi guys.

    I guess I am close the solution but I would like to have your confirmation.

    I bougth a usb-rs232 cable:
    RS232 PL2303HX 1m Z54

    This cable has a supply of 5V when connected to a PC. I want to test a wifi module (ESP8266). I understood that I need to drop the voltage to 3.3 probalby using 2-resistor circuit from the 5 V provided by the cable but I am still not sure if If can connect directly the TX and RX of the cable to the ones on the module. ( need to use teraterm for testing purpose).

    What abut the rs232 level provided by the PC? As far as I understood the diode zener is necessary when I want to connect the module to a PIC but what about PC?

    http://rayshobby.net/?p=9734

    Thanks a lot

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  2. #2
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    Re: I want to test a wifi module (ESP8266)

    come on man you need a real FTDI cable or an older Prolific serial to TTL cable; each is only few bucks. The whole business with zener diode and resistors would likely fry the ESP. I got these FTDI cables with a little switch to change the TTL levels between 5v and 3.3v;

    I fully expected fake FTDI ICs but lo and behold what came from AliExpress was a real IC which was immune to the November driver snafu and it works perfectly with the ESP module. On top of that the seller actually dropped off the package within few days of ordering (that has been a typical problem with Ali where sellers wait a week or more before actually dropping off the packages at their post office -- I guess they want to make sure they get the money first)

    http://www.aliexpress.com/snapshot/6...64880993130131



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  3. #3
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    Re: I want to test a wifi module (ESP8266)

    Quote Originally Posted by ds18s20 View Post
    come on man you need a real FTDI cable or an older Prolific serial to TTL cable; each is only few bucks. The whole business with zener diode and resistors would likely fry the ESP. I got these FTDI cables with a little switch to change the TTL levels between 5v and 3.3v;

    I fully expected fake FTDI ICs but lo and behold what came from AliExpress was a real IC which was immune to the November driver snafu and it works perfectly with the ESP module. On top of that the seller actually dropped off the package within few days of ordering (that has been a typical problem with Ali where sellers wait a week or more before actually dropping off the packages at their post office -- I guess they want to make sure they get the money first)

    http://www.aliexpress.com/snapshot/6...64880993130131
    Hi Thanks for the answer . I did not completly get it.
    RS232 PL2303HX 1m Z54 this is a cable with 5V as Vcc all i need to do is dropping in somehow to 3.3V. What about RX and Tx? Is any circuit example I can refer to connect the module to a PC using the cable below?



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    Re: I want to test a wifi module (ESP8266)

    An RS232 cable WILL NOT DO. You need a ttl level cable with the ttl being 3.3v

    In addition to that you need to power the module with 3.3v; if you don't have a bench supply then you need a 3.3v buck converter (dc to dc) or a 3.3v regulator such as the AP1509; it's only few cents

    https://www.google.com/url?sa=t&rct=...83339334,d.cGU

    So to review:

    1. a ttl serial with 3.3v ttl signals
    2. a 3.3v voltage regulator or buck converter to power the module from

    Click image for larger version. 

Name:	33v.png 
Views:	2 
Size:	140.4 KB 
ID:	113118



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    Re: I want to test a wifi module (ESP8266)

    Thanks for the information. I ordered this one for ttl:

    http://www.ebay.com/itm/FTDI-Basic-6...E:L:OU:IT:1120

    Regarding the 3.3 voltage any suggestion for something which fits to a breadboard?

    ;)
    Thanks



    Quote Originally Posted by ds18s20 View Post
    An RS232 cable WILL NOT DO. You need a ttl level cable with the ttl being 3.3v

    In addition to that you need to power the module with 3.3v; if you don't have a bench supply then you need a 3.3v buck converter (dc to dc) or a 3.3v regulator such as the AP1509; it's only few cents

    https://www.google.com/url?sa=t&rct=...83339334,d.cGU

    So to review:

    1. a ttl serial with 3.3v ttl signals
    2. a 3.3v voltage regulator or buck converter to power the module from

    Click image for larger version. 

Name:	33v.png 
Views:	2 
Size:	140.4 KB 
ID:	113118



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  6. #6
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    Re: I want to test a wifi module (ESP8266)

    the cheapest 3.3v PSU is this: rip off an old beat up power supply from some crappy computer; cut the main connector and you have 3.3v 10 Amps plus the bonus of all the other voltages: 12v 5v and -12vClick image for larger version. 

Name:	20-pin.jpg 
Views:	2 
Size:	14.9 KB 
ID:	113129



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