I've been trying to use AT mode on my Bluetooth board using a freenove control board aka Arduino Uno but nothing has worked I've gotten a bit of corrupted message but mostly nothing. I've tried making custom rx and tx ports for the module but I've gotten nothing. I've watched so many videos they all are different in some way, like some don't use voltage dividers some use them and the resistors that they use are all different. I just don't know how to do it.
on the tx of the Arduino to rx of the module I've the resistors I'm using 3 1k resistors so R1 is 1k and R2 is 2k .and nothing to the rx of the Arduino to the tx of the module. Ive also been holding the button on the board when i power it on to change it into AT mode
here is the layout of the board just pretend the 4 digit display is the Bluetooth board
for the serial port I used 9600 as where I bought it from said that the default was 9600. I've used lots of different code in case it was the code but nothing helped but it still could be the code.
Also I only have 1k, 10k, 510 and 220 resistor and I don't really want to buy anymore so if its possible I would not like to buy any more resistors.
Are you sure that your modules are HC05? Please post photos, front and back.
I suggest that you use a software serial port for the HC05. Keep the hardware serial for program upload, debugging and monitoring program flow and variable values.
On some HC05 boards the button allows only limited AT mode. Use the EN pin to put into AT mode. Never apply 5V to EN, 3.3V only. See my tutorial on setting the HC05 to AT mode. The tutorial shows the voltage divider and how to code for software serial. The tutorial also has links to more information on using the HC05.
The software serial method is more popular on this forum, so I suggest you try that first. Post your wiring and code. A hand sketch of the wiring is better than the Fritz image.
I suggested Software serial for developement. But Software serial is limited to 38400 baud, at best. Then once everything is working well you can switch to hardware serial and take advantage of the higher speeds available.
