Messages

1

TinyDuino Processors & TinyShields / SD Card Module power drain

« on: December 08, 2015, 02:56:56 PM »

Hi,

I'm making a mini motion data logger using the 9-axis shield, RTC shield and Micro SD card module, stacked onto a button-cell tinyduino mainboard.

The button cell seems not to have the current draw ability to power the SD card module on it's own, but with some parallel ceramic capacitors, I can manage to write to the SD card in bursts as required.

My code puts the tinyduino into full power off sleep between write operations, so the draw from the main board is minimal. However, when the SD card is inserted, the power draw is high all the time, even when the 'duino is asleep. As a result, the button cell drains really quickly and I end up with <2.8v and brown-out within minutes.

Is there any way to stop the MicroSD drawing power all the time? Or is there an alternative memory I could use that doesn't draw power constantly?

Any help much appreciated.

:-) Thanks

2

New Product Ideas / Re: EEPROM/RAM/Coprocessor "Utility" board

« on: November 05, 2015, 05:24:45 PM »

+1

I'd like this too.

3

TinyDuino Processors & TinyShields / Logging 9axis IMU data to Micro SD card

« on: November 05, 2015, 02:32:46 PM »

Hi All,

I'm not a complete arduino noob, but not far off, so forgive me if I'm making a stupid error here.

I have the TinyDuino 9axis IMU shield and Micro SD shield, and would like to log the data from the IMU to a Micro SD card.

The problem I'm having is that the 9axis IMU library seems to assume that data will be output on Serial.print. I need to output on dataFile.print to go to a MicroSD. I have tried modifying the library files a bit, but without too much success. I end up chasing my tail.

Basically, I want a combination between the Arduino 'Datalogger' example and the "TinyShield_9_Axis" example.

Thing is, these lines in "TinyShield_9_Axis" are just outputting on serial:

RTMath::display("Gyro:", (RTVector3&)imu->getGyro());                // gyro data
RTMath::display("Accel:", (RTVector3&)imu->getAccel());              // accel data
RTMath::display("Mag:", (RTVector3&)imu->getCompass());              // compass data

It seems when you trace these back to RTMath.cpp, they refer to

void RTMath::display(const char *label, RTVector3& vec)
{
   Serial.print(label);
   Serial.print(" x:"); Serial.print(vec.x());
   Serial.print(" y:"); Serial.print(vec.y());
   Serial.print(" z:"); Serial.print(vec.z());
}


I have tried modifying RTMath.cpp and changing Serial.print to dataFile.print, but of course it then requires SD.h which it doesn't see.

Can anyone help me here? I may well be going about this completely the wrong way.

Has anyone successfully written 9axis shield data to a MicroSD?

Many thanks
tinyvino