To BLE or not to BLE... that is the question.

Hi everyone!

I'm working on the design of a new and hopefully inexpensive robot similar to the “scribbler” with a few additions that should make it a slightly better educational tool. Among these additions is Bluetooth and/or wifi communications. The design WAS about 99% done until I received the HM-10 modules I ordered on ebay and tried to connect one. These modules will not pair with my Android phone (version 7.0) I have managed to get the module to take limited AT commands from the processor and the module will connect with a Bluetooth program on my Android, but it still will not Pair so that I can use them with an Android terminal program .

A couple of days of searching the internet leaves me to believe that I can build a serial programmer and reprogram the firmware... but this seems a pretty round-about way of hooking up what I hoped to be a simple wireless UART.

I know that Parallax sells a Bluetooth module that probably would work great, but $59.99 is more than my entire budget for the rest of the robot. I know that there are many modules out there. HC-05, HC-06, HC-ETC . Most of these modules are based on TI's CC2540 or CC2541 chip. These modules are plentiful and cheap. If I had guessed right and got one that worked “Out of the box” I wouldn't be looking for something else, but here are my questions:

Does anyone out there know of a cheap, simple module that you have success with “out of the box” that will do these things. ( I eventually hope to have robots that can communicate with each other as well.) I'm trying to keep the communications unit under $10.00.

Given your druthers... would you prefer to purchase a robot kit with a simple and inexpensive of wireless such as one of these HC or HM modules or should I take the time to get up to speed with the esp-32 and redesign my new board around it? I'd be interested in opinions on either side of the fence.

Any feedback would be appreciated.

Ken B.


  • tonyp12tonyp12 Posts: 1,950
    edited 2017-06-01 - 02:54:42
    BLE don't officially support being a simple uart serial bridge.

    You need to use GATTS, example 4.2 have ipv6 and Object Transfer Service
    Silicon Labs and Cypress ble modules, you set the type with its gui ide studio.
  • Wouldn't an ESP32 module do what you want? Plenty of those around, pretty cheap.
  • FYI, there is a socket inside of the Parallax S3 robot that will accept their WX wi-fi module. I've tried it and it seems to work.
  • I suspect the ESP32 would work great Heater, I have a couple of the development modules and a couple of the ESP-WROOM-32 modules on order to see how easy they are to work with. I imagine I will have a future version that uses these chips however I'm hoping to have a bot that can be purchased for under $100.00 and every extra dollar makes this less likely to happen. The WROOM modules can be purchased for $3.95 but the development modules are still in the $10+ range.

    The S3 with the WX module on it would be nice David, but cost about twice what I'm hoping to produce something similar for. I've got about $35 into my prototype bot now, if I can have a 4 layer board made cheaply, I should be able to keep manufacturing cost close to this range.

    I'm going to check out the HC-06 first, at $.99 each, if it will do what I need it's probably the best for a "Beginners" robot.

    This is my first time working with wireless. I'm sure I'll get more familiar with all the terms and procedures soon... but I'm at the bottom of the learning curve right now, I'm hoping to KISS at this stage of the game.

    Thanks Guys.

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