This aberrant behavior could cause many people not to use this module. And in this case the disconnection should be complete: the master should notice it and the module should refuse to receive. Once connected, no AT command should be possible, and if we wanted to be able to force a disconnection from the slave side, we would have to use an I/O pin. But the link is not completely broken, the remote master remains connected and you can continue to receive the data it transmits.
#TERA TERM VS PUTTY BLUETOOTH#
In conclusion of the data transmission tests, the Bluetooth connection is easy, and the module seems able to transmit any type of dataĬAVEAT: In data mode (or connected state) one AT command is accepted! If you send AT+DISC you get an answer: +DISC:SUCCESS, then you can no longer send data. This contradicts some websites which say that the module transmits only after receiving a CRLF, which would imply that it cannot transmit arbitrary binary data since it buffers the data and CR and LF have special meaning.Īdditional tests were carried out with a Bluetooth terminal allowing the transmission and reception of hexadecimal characters ( Bluetooth Terminal – Qwerty):Īrbitrary hexadecimal characters are transmitted as soon as they are supplied, without requiring a CRLF. CR, LF or CRLF are transmitted like the other characters.Characters are transmitted as soon as they are supplied, in both directions.The connection in data mode is automatic, and by default.
#TERA TERM VS PUTTY PC#
On the PC I run Putty in 9600 baud and bingo! A character typed in Putty appears on the phone, and a character typed on the phone appears in Putty. The BlueTerm Bluetooth terminal can connect to the module. It’s confusing at first.Īs soon as the module is powered on, it appears in the list of Bluetooth connections on the smart phone, and it can be paired. The JDY-31 module is to be supplied with 3.3V, which is handy to connect it to a Cortex-M type microcontroller such as an STM32. I am using a serial/USB converter which has a jumper to connect its VCC pin to the 5V from USB or to the 3.3V of the FTDI232.
It is a priori easier to experiment by connecting the module to a serial/USB converter then to a PC, than directly to a microcontroller. But on reflection things have become clearer. The information available on the net did not allow me to get started easily. It is not clear if this document apply to JDY-30 or JDY-31. Jdy-30-bluetooth-module.pdf: Source KO4BB. JDY-31_manuel_2.pdf: Unknown source, seems to document the JDY-31. These are slave modules (like the HC-06). One thing is certain: the module is configurable with AT commands. Some documents mix the information on the two types of modules. I couldn’t find an official doc, and all of them have roughly the same information, regarding V1.2 or V1.3 software. It is also more convenient with the possibility of directly soldering a header. The JDY-31 appears to be newer and uses the BK3231S chip. This circuit seems obsolete and sellers replace it with a JDY-31. It is recognizable because it does not have the holes to solder a header. The JDY-30 seems to be the first to appear, and uses the BK3231 chip.