RN-42 Bluetooth Module

jplrobot

How do I mount the RN-42 Bluetooth module in the AppMod Header of the BOE? The RN-42 has 7 pairs of pins while the AppMod header has 10 pairs of sockets and has Vin and Vss at its opposite ends. Any help is appreciated.

Thanks.

Mike Green

You don't. The RN-42 board is not designed for use with the AppMod header. You can make connections from one to the other using wire jumpers and you can make an adapter board if you want. The RN-42 board is primarily designed to plug into a breadboard with wire jumpers used to connect to a source of power (Vdd and Vss) and data lines (Rx, Tx, and optionally /CTS, /RTS, and /RST).

jplrobot

Thanks. Would you know if there is a tutorial on how to hook this up to the BOE? Past literature shows that the Easy Bluetooth Module was plugged into the AppMod header. Wonder why Parallax went away from that approach. The RN-42 guide is not very explicit on the mounting aspect you mentioned.

Mike Green

The RN-42 documentation shows you how to connect the module to a source of +5V power. In the case of the BOE, this is Vdd and Vss. You can use any labelled connection on the BOE marked Vdd and Vss including the ones on the AppMod connector. As far as the data lines, it depends on what I/O pins you want to use. The sample code in the documentation uses I/O pins 0-4 as shown on page 6, but really you could use any of them and you only have to have Rx and Tx as discussed in the documentation.

The AppMod connector hasn't really been used for a while and none of the newer (Propeller) boards support it. At this point you're not going to see any new development using the Stamps.

jplrobot

Thank you for your help. I need get up on the learning curve before I use the RN-42. The AppMod header would have made it so convenient for the end user.

jplrobot

Thank you for your help. I need get up on the learning curve before I use the RN-42. The AppMod header would have made it so convenient for the end user.

Mike Green

It's pretty easy to plug the RN-42 module into the little breadboard socket on the BOE and place 5 jumper wires ... One from Vin on the module to Vdd on the BOE, one from Vss to Vss, one from RX to P0, one from TX to P1, and one wire between RTS and CTS on the module. That's all.

Chris Savage

jplrobot wrote: »

The AppMod header would have made it so convenient for the end user.

Making the R-42 Bluetooth Module use the AppMod header would have been convenient for those who have that header on their boards. However, many will be using a breadboard or in my case, people like me won't even be plugging it in at all. I tend to mound the module where it is convenient and use pluggable wires to connect it to my board of choice. This is why the connection diagram is more generic. It allows for any system to use the module, not just Parallax boards with the AppMod header. Take care.

jplrobot

Mike, is RX connected to P0 or P2? The example program for the RN-42 shows:

Reset PIN 0 ' To RN-42 RST pin
TX PIN 1 ' To RN-42 RX pin
RX PIN 2 ' To RN-42 TX pin
CTS PIN 3 ' To RN-42 RTS pin
RTS PIN 4 ' To RN-42 CTS pin

Thanks for your help.

Mike Green

This particular example uses all 5 signals, RST, TX, RX, CTS, and RTS in that order from P0 to P4. I described the minimal connection which only requires TX and RX. The documentation indicates that RST doesn't have to be connected and RTS is connected to CTS, but neither is connected to an I/O pin.