Openlog MicroSD data logger module

[flotulopex]

Hello There,

Did by chance anyone out there already hookup an Openlog module to a PIC?
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I can't find any code example to help me getting started....

BTW, the BLK pin goes to GND and the GRN should be connected to DTR but I have no idea how to handle this signal.

[flotulopex]

Currently, I'm connected to the module via an FTDI cable to a terminal.

This works fine.

But how do I make it work with the PIC?

[tumbleweed]

...and the GRN should be connected to DTR but I have no idea how to handle this signal.
I've not used one, but from the looks of it the GRN pin is attached to the reset pin of the ATmega. By pulling this pin low, it will reset the OpenLog.
You can probably leave it unconnected (it has a pullup to 3.3V), or connect it to an output IO pin.

You would connect the module to the UART serial port of the pic and send the same commands you use in the terminal.

BTW, the Openlog is a 3.3V module, so you would have issues directly connecting it to a 5V uC or FTDI cable.

[Ioannis]

This OpenLog has on-board low drop regulator (MIC5205-3.3) and works from 3.3 up to 12Volts. Recommended 3.3-5Volt obviously for power dissipation reasons. So power is no problem to be connected to 5Volts.

But do not know if the ATMEGA328 is tolerant on 5volt at the pins having 3.3 volts on power supply.

Ioannis

[tumbleweed]

It's not, which is why I raised the issue.

Ioannis correctly points out that it has a 3.3V regulator onboard. The ATMEGA IO pins are spec'd to VCC+0.5V, so that'd be a max of 3.8V.
You'd want to use a level translator with a 5V uC, or a 3.3V FTDI cable.

[flotulopex]

...or a 3.3V FTDI cable.

Yup, this is what I'm using for now.

Still looking how to control the module via Terminal and go further (to PIC) once understood how the module really works and does.

[flotulopex]

BTW, I need send some control character in order to change his function mode.

But, it seems I'm doing something wrong.

The modules expects me to sent ctrl+z (ASCii 26) three times in a row to change its mode.

I have enable the "Parse control Characters" in the MCS Serial Communicator and sent #26 three times but nothing never happens.

In fact, I tried a lot of different ways with/without Parse option, sending ESC before the command and so. Still, nothing does.

What am I missing?

[Ioannis]

If you type the characters, then maybe you are timign out.

Maybe using the Br@y terminal (https://sites.google.com/site/terminalbpp/Terminal20141030.zip?attredirects=0&d=1) you can send at once the string of these characters.

The above terminal has a field that you can type in the characters and send clicking a button.

I suppose you have cross checked tx and rx lines are connected correctly.

Ioannis

[flotulopex]

Thanks Ioannis.

I tried the Terminal already and it doesn't work too.

The communciation with the module is working. There is an option to modifiy the "config.txt" on the SD card that allows one to modify parameters such as operating mode on startup - which I did.

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But the idea is to have the module launched in "logger" mode and if needed, to be able to toggle to "command" mode via control characters.

Unfortunately, this doesn't seem to work easley....

I'm contacting the guys from SparkFun and see if I can get any help there :wink:

Anyway, thanks a lot for your help.

[Ioannis]

Can you control anything through the terminal?

Ioannis

[flotulopex]

I just got one step further.

The manual says that the control character must be sent three times in a raw. Well, so I did wrongly: #26 + enter, #26 + enter and #26 + enter.

But this is how I just finally made it: #26#26#26+enter.


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The module's response at "logger" mode launch is "12<". Toggeling to "command" mode adds "~>".

Took me a few hours of searching but finally got there :)

...might help someone else....

[flotulopex]

Yes, I was already able to communicate with the module before by modifying the "config.txt" file on the SD card.

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[Ioannis]

Well, the 26+enter is something that cannot be debuged from a distance!

I suspected that something in sending the command was not right and that is why the br@y terminal was proposed. But in that case also there would be a problem if you would not use 26 26 26 and hit then send button.

Glad you sorted out and wish you best of success wiith the rest of the experiments.

Ioannis