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Connecting EC1 to a JY-MCU Bluetooth module

This EasyStep will show you how to connect your EC1 "EasyOne"to a low cost Bluetooth module. It shows you how to wire the module to the EC1 and to pair and connect to your phone.

I use the JY-MCU Bluetooth to serial slave adaptor module. (JY-MCU seems to be a brand name!). I buy them from here, but feel free to google other sources online. They cost less than $10 delivered.

Note:These cheap modules use 3.3V signals and are not compatible with our 8 bit products, which have 5V signals. If you use one on say a CC18, at best it will fail immediately, and at worst it will fail 3 weeks after you sell the product that contains it. We offer our own Bluetooth modules, BT-TTL5, that contain the appropriate 3.3V to 5V translation circuitry.

Wiring

The picture below shows the wiring. The module comes with (or at least, mine came with) a 4-wire connecting cable with wires I can best describe as Morse coded. I have shortened the wires in the picture. Note very carefully the "twist in the wire order" On the Bluetooth module Vcc (+ supply) and Gnd (0V) are pinned next to each other. On the EC1 they are at either end of the connector. When plugging in to the EC1 you skip the end pin and use the next 4.

Make the connections with no power to the EC1 (you should never connect or disconnect stuff with power on!). Then check your connections. Then compare them again to my picture. If in doubt verify each wire between the Bluetooth module and the EC1 using the EC1 I/O map. Do not use the markings next to the white serial connetor on the EC1 - they apply to that connector, not the edge pins.

Hint: Once I have the pins properly sorted I wrap them in tape, label them as to which end is which, and make a special mark on (say) the Vcc pin.

Pairing

Pairing is the process of introducing the Bluetooth module to your Android 'phone. It is the first step in making a connection between the two. Here is the general procedure. I don't have any screen shots because a) they will vary from device to device, and between Android versions, and b) I can't get screen shots off my shiny new Google Nexus 4 'phone.

What next

This EasyStep was just about the basic, essential move, of getting the BLuetooth module wired correctly to the EC1 and paired with your 'phone. The next step will be a sample app using Bluetooth to Android.