help for RN-41 Bluetooth modem

Wireless & IoT
1

hi, I’m facing a problem with modem RN-41

the first problem that when i connect Vcc(3.3v) to the modem and measure the volt i find it 1.68 v

i don’t know why this voltage drop occur

you can find my connection in this url http://i64.servimg.com/u/f64/11/34/70/98/untitl11.jpg

is any thing wrong or missed ?

the second that when i apply logic 1 (5v) to max232 it gives -6v

and when apply logic 0 (0v) i get +6v, although pc voltage -12/+12

so is the pc will understand -6 as logic 1 instead of -12

and +6 as logic 0 instead of +12

note that i’m using level converter to convert from 5v TTL coming from max232 to 3.3v for modem RxD

2

Interesting that both voltages are about half of what you would expect. I would verify that your meter is working properly, or if you are using a scope that the scaling on your scope is coreect. Also verify that you have good grounding and you are checking from the proper ground point.

Also, instead of using a level shifter, you could use a MAX3232 which runs off 3.3V.

3

I checked every thing more than one time and all is o.k

i’m afraid that the module is corrupted

because i disconnect all connections for all components except the Vcc and GND terminals of the modem and also the voltage dropped to 1.6V

i’m puzzled .