Data storage onto memory card (e.g. SD)

Bluetooth, USB, UART, Storage, etc.
BITalino
Site Admin
Posts: 567
Joined: Tue Aug 27, 2013 3:47 pm

Data storage onto memory card (e.g. SD)

Postby BITalino » Sun Sep 08, 2013 2:56 pm

BITalino is fitted with a standard UART interface, which is used for communication between the MCU and the Bluetooth module.

You can always replace the Bluetooth module by a third party or custom made memory card module with UART interface.

Frédéric
Posts: 3
Joined: Thu Feb 06, 2014 5:00 pm

Re: Data storage onto memory card (e.g. SD)

Postby Frédéric » Thu Feb 06, 2014 5:06 pm

Hello,

The problem is if we replace the bluetooth component by a data storage component with UART interface, we can't transmit our informations. Maybe we have to set a trigger component to transmit one way on the bluetooth and on the other way on a data storage.
So, how can we pilot it ? Is there a pin available on the micro controller to do this ?

Yours sincerely,
Fred

BITalino
Site Admin
Posts: 567
Joined: Tue Aug 27, 2013 3:47 pm

Re: Data storage onto memory card (e.g. SD)

Postby BITalino » Thu Feb 06, 2014 9:36 pm

Frédéric wrote:Hello,

The problem is if we replace the bluetooth component by a data storage component with UART interface, we can't transmit our informations. Maybe we have to set a trigger component to transmit one way on the bluetooth and on the other way on a data storage.
So, how can we pilot it ? Is there a pin available on the micro controller to do this ?

Yours sincerely,
Fred


A nice way to go about would be to implement the control logic on the data storage component (e.g. short button press to start acquiring, long button press to stop acquiring, etc.). This has the advantage that your system will not depend on a "base station" like a computer or smartphone.

Nonetheless, the Bluetooth module is a transparent proxy for the data sent to and received from the MCU, and we have no "handshake" on the commands supported by the firmware.

As such, you should be able to have just the TX on the Bluetooth block connected to the MCU (which will allow you to send commands to it), and cut the RX line in order to have the data sent to your data storage component.

Best regards,
The BITalino Team

Frédéric
Posts: 3
Joined: Thu Feb 06, 2014 5:00 pm

Re: Data storage onto memory card (e.g. SD)

Postby Frédéric » Fri Feb 07, 2014 1:57 pm

If I don't use the "lux" component, can I replace this component by a trigger component that i could control directly with the firmware ?

BITalino
Site Admin
Posts: 567
Joined: Tue Aug 27, 2013 3:47 pm

Re: Data storage onto memory card (e.g. SD)

Postby BITalino » Fri Feb 07, 2014 2:08 pm

Frédéric wrote:If I don't use the "lux" component, can I replace this component by a trigger component that i could control directly with the firmware ?


You can indeed disconnect the LUX component, and connect another component capable of producing a digital or analog signal to that channel.

The digital input ports also allow you to synchronously record data from external components such as a switch for example.

Note however that, for the time being, the firmware on the device is non-programmable, and it cannot be configured to respond to such signals.

To have "conditional" data recording, you have to either adapt the existing or create your own custom software to detect the trigger from the external component and start / stop data recording on a base station (e.g. computer or a smartphone).

If you'd like to have an autonomous system for data logging, the BITalino control logic needs to be on another component (e.g. Arduino or Raspberry Pi).

Frédéric
Posts: 3
Joined: Thu Feb 06, 2014 5:00 pm

Re: Data storage onto memory card (e.g. SD)

Postby Frédéric » Fri Feb 07, 2014 3:47 pm

Ok so if I understand, I connect BITalino RX and TX on the Raspberry PI et I can receive datas from captors. Then I can save datas in the SD Card.
When the bluetooth is connected with a device, I transmit the datas contained on the SD Card. Is it possible ??

BITalino
Site Admin
Posts: 567
Joined: Tue Aug 27, 2013 3:47 pm

Re: Data storage onto memory card (e.g. SD)

Postby BITalino » Sat Feb 08, 2014 8:40 am

Frédéric wrote:Ok so if I understand, I connect BITalino RX and TX on the Raspberry PI et I can receive datas from captors. Then I can save datas in the SD Card.
When the bluetooth is connected with a device, I transmit the datas contained on the SD Card. Is it possible ??


Yes, if you connect the UART pins (RX/TX) to a Raspberry Pi, you can record the data there. We have example code in Python available on GitHub, but you may want to implement your code in C/C++ for improved performance: https://github.com/bitalino/bitalino-raspberryPi

Once you have the data recorded, you can then use any transfer method you find more convenient. The simplest way should be to read directly the data from the SD card on your computer, but Bluetooth streaming or event USB access should also be possible.


Return to “I/O”




cron