HC-11 433Mhz trancievers can not coax any life out of

Good morning folks.

I’m hoping someone can shed some light on an issue that I’m having with a pair of new HC-11 433Mhz transceiver modules.

The intention is to replace my current set up that uses a one way MX-FS-03V and MX-05 transmitter \ receiver pair that with the aid of home made ¼ wave whip antennas and Virtual wire gets me a cheap and reliable 20 metre range to my remote workshop and wind turbine. I am intending to replace this system with the HC-11 transceivers to gain 2 way communication so I have both data logging and control.

My problem is that I cannot coax any sort of useful life out of these modules, First off I wired them up as a simple replacement to a working wired serial between a pair of Arduino’s, nothing doing. So tried the coms test as per the data sheet, ie. Fire an AT command and wait the “OK” reply, again nothing, tried swapping tx and rx lines over as we have all had these swapped at some point, once again nothing. I have tried upper and lower case “AT”, (using the Arduino IDE serial monitor and my serial), I have tried all permutations of line feed, carriage returns ect, I have tried holding the modules control input high \ low, pulsed monetarily low, still nothing. The only slight sign of life is if I hold the control input low ( which according to the data sheet enters the module into setup mode) then cycle power to the module I receive 2 characters on the serial monitor screen every time the power is cycled, these are a square followed by a y with 2 dots above which I believe to be the ascii character indicating no data (think it might be -1). I tried changing the buad rate of my serial to 4800 but strangely receive the same characters.

So, anyone else out there had these modules working? I have spent some time searching but am struggling to find anyone using these modules or has asked for help so either I’m the only one to have troubles or no one else has used them.

Many thanks in advance for any help.

After some searching…

The baud rate by default is 9600 you could use SoftSerial, but there’s little to go wrong by the looks of it