Member Since: July 5, 2007

Country: United States

  • David's Manual:

  • I thought about additional header data, but I'm not sure if it is necessary. The pictures are named based on which trigger generated the picture. 0_xxx corresponds to trigger 0, and 1_xxx corresponds to trigger 1, the xxx is incremented every time a picture from that trigger is taken. So there is no need for trigger data in the header. Time would be good to have, but the AVR does not have an RTC, so this would require additional hardware.
    What other information would you need?

  • Sorry, this part is made by 4-D systems, not sparkfun. Trust me, I would like to know what the IC is as well ;)

  • agreed, that smile just isn't working for me....

  • The numbers you are seeing are raw ADC conversion results. In order to understand the output you will first need to know how to convert this number into a voltage. The general ADC conversion equation is this (you can find it on page 256 of the ATMega168 datasheet):
    raw ADC value = (Vin * ADC resolution)/Vref
    in this case ADC resolution is 10 bits, so 2^10 is 1024. The Vref is 3.3V, and the raw ADC value is the value the atomic is outputting. So if the z axis is 770, the actual Vin is about 2.48V. Now you need to use the MMA7260Q datasheet. On page 3, there is a table that shows the resolution and zero values for the accelerometer. At zero g the accelerometer is supposed to output about 1.65V. take this value and subtract it from the 2.48V and this gives how many volts above zero g the accelerometer is experiencing, so in this case about .83V. Now if you look at the sensitivity of the accelerometer (also on page 3) you can see that at 1.5g range the sensitivity is about 800mV which means the z axis is reporting almost exactly 1g, as it should be. You can follow the same procedure for the gyros.
    You can also calibrate the accelerometer by seeing what the actual zero-g, and 1g readings are for your unit. to do this all you have to do is take a reading with z axis experiencing 1g (you have already done this), and with the z axis at zero g (to do this all you have to do is hold the atomic vertically). You can use this zero g value as your zero g reference and the difference between the 1g and 0g reading as the accelerometers actual sensitivity. This can also be done for the other accelerometer axes.

  • The accelerometer is not included with this board so that you can choose what you want to log. If you want to use the accelerometer used in the rocket flight, have a look here: http://www.sparkfun.com/commerce/product_info.php?products_id=848
    To program the ATtiny24 you need to use an avr programmer. The avr programmers that we sell program the avrs using an ISP header. The inconvenience about this board is that there is not enough room for one; however the necessary pins are broken out. have a look online for what pins you need to use, or have a look at the beginning embedded electronics tutorials (https://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=93) on how to wire up an ISP programming header.
    The ATtiny24 is an AVR microcontroller. The problem is that the firmware needed to write/read from the eeprom and read from the adc channels almost fills up the entire programming space. This means there is very little room for additional data manipulation.

  • I haven't used this part with I2C, but the posted sample code should get you started with SPI. It's written in C but it should point you in the right direction for how to write your arduino sketch.

  • Hi,
    ->Yes the atmega168 is programmed
    ->No, the datasheet should be enough
    ->Check your connections. Make sure that the LCD is getting at least 6V, the GND from your atmega16 is connected to the LCD, and that the RX pin from the atmega16 goes to the TX pin on the serial backpack.
    if you need anymore help, feel free to email tech support :)

  • The original image is posted now. It looks distorted in the preview but if you enlarge it you can see the original size.

  • well if if it's from Sparkfun I would email tech support (I know a thing or two about tech support).

No public wish lists :(