Need help with writing to Charateristics to turn motor on and off

[Nick]

I have a 32u4 Feather but don't get the right support from Adafruit to create my own Profile. I have downloaded Nordic's android app and can see all the characteristics on the board. But I have no clue how to interact with it. All I want is the chip to accept input from a smartphone such as listining to a character for instance "o". If the "o" comes in it should then open up a port to power the motor driver which then powers a small motor. I would need help how to do this. This board has preconfigured stuff on it I never even heard off and don't need. However, I can see from your app that it is possible to write to empty characteristics. Is this what I need to do for my project. Or how do I do this on this BLE device. Or would it be easier to purchase a new BLE device from a differnet vendor? If so, can you recommend one for me? It was real easy previously with the classic bluetooth. Now with BLE its gotten real difficult. Can't do it on my own. Need assistanc please. Thanks, Nick

[Nguyen Hoan Hoang]

I don't if it could any help but for alternative have look at this blog. There are source code examples and some old iOS examples.

[Jørgen Holmefjord]

Hi,

Is this the board you have? It looks like it runs the Nordic UART service, and that the UART messages is transferred to the ATmega32u4. I'm not sure how you handle the data in this chip, but I guess there are some examples available somewhere.

If you want to get another board, I would recommend the nRF52 DK. In our SDK, you can find examples of how to use all peripherals on the IC, and how to setup various BLE applications. You can find information about how to control LEDs (set/clear pins) and servos (using PWM) over Nordic UART service over BLE from our iOS/Android app on this page.

Best regards,

Jørgen

[Nick]

Hi Jorgen, Thx for the reply. Is this the board you have? Yes, that's the board. And yes it uses the Nordic service and chip. However, I'm not getting any support from them how to write to the chip such as a profile, service or characteristic. That's why I'm trying to get help from Nordic. The link "this page" shows the code format for the board nRF52 DK. It makes sense to me. However, that board nRF52 DK is way too big for my project. But the code is very similar to the one from Arduino. I just thought since the 32u4 has the Nordic chip on it that Nordic would be able help me to write to the server chip since Adafruit doesn't help. I just can't use such a big board. I need a small footprint but no programming on it such as Heartrate, gyro, accellerometer and so forth. Then it has the app with all those features available. I don't need all that. I want something small, that I can put that small code on it for to turn a "PIN on and off". Then I need to be able to write my own app(UI) for it. Just 2 buttons on it. One for "open" and one for "close". That's all I want. There is got to be a way to find help from you guys with that or finding such a small board. Thanks, Nick

[Nguyen Hoan Hoang]

The link I gave you in the comment above has small board 17x23mm and breakout board and examples code doing exactly what you wanted, even iOS code for that.

[Jørgen Holmefjord]

The "problem" you have with your board is that you are not supposed to write Nordic code and flash to the BLE device. The nRF51 chip inside the BLE module is flashed with some custom firmware, that talks to the ATmega chip via SPI interface, making the nRF51 chip more of a connectivity IC than a system-on-chip. Looking at the schematics, the SWD interface of the nRF chips is exposed on the board, allowing you to change the firmware of the BLE module. However, not many pins of the nRF51 chip is exposed on the boards, so you will be limited in GPIOs. By connecting an external debugger to the SWD interface, you should be able to flash applications created by using the nRF5x SDK to the chip.

If you fint the nRF52 DK too large for your project, we have a long list of 3rd party module parteners, and there are also others creating development and breakout boards with our nRF5x chips.