ADIS16250: Help with setting up SPI

[InitialDriveGTR]

Do you know what the "LSB" is on the ADIS16250 datasheet? I think it is being used as a unit. Thanks

PS mister_e, I could host your calculator software on my website if you would like

[SteveB]

Do you know what the "LSB" is on the ADIS16250 datasheet? I think it is being used as a unit. Thanks

Yes, it is. See Table 6. On the far right, it shows that each bit, for the different outputs, represents a particular values. For instance, each bit of the GYRO_OUT register is equal to 0.07326°/sec (when scaling is set to 320°/sec). So, if this register was %0000 0111 1101 0000 (2000), it would mean a value of 2000 * 0.07326 = 146.52°/sec.

If you look at table 1, you see the SENSITIVITY parameters (Compare this to table 7):
Range = 320°/sec, LSB is 1/13.65 = 0.07326 °/sec
Range = 160°/sec, LSB is 1/27.30 = 0.03663 °/sec
Range = 080°/sec, LSB is 1/54.60 = 0.018315 °/sec
EDIT: These numbers are also presented in the text below table 12


HTH,
Steve

EDIT: Here is a link to the datasheet to keep others from having to search for it.

[mister_e]

PS mister_e, I could host your calculator software on my website if you would like

I have no problem with that. Another site already did it without my permission anyway

If you get cash from it, i'm also wide open

[InitialDriveGTR]

Hello, I am working trying to display the degrees per second on an LCD. I want to have accuracy with the displayed value, but for now would be happy with just integers. Can someone help me figure it out? Thanks

[Payatronico]

Hey, how do you want to aquire the temperature? and I can't understand how do you want to calculate degrees per second? explain me better and I will try to solve your problem. If you don't have an idea I can give you some ones.

[InitialDriveGTR]

I have a LCD connected to my PIC, and I wish to display the rotation of the Gyro in degrees per second. I need decimals, and I am having trouble working out the math without maxing out the word variables. Thanks

[SteveB]

Give us a little more information or an example of what you are trying to do. With the DIV32 command in PBP, you can work around a lot of math issues by shifting the decimal point to the right before you do the math. By keeping track of the magnitude of your decimal shift, you can display the result as needed.

Here are a couple of nice threads by Darrel Taylor dealing with exploiting PBP's integer math:
32-bit Variables and DIV32, Hourmeter 99999.9
Retrieving 32bit Multiply Result
Retrieving Div32 Remainder

Steve

[InitialDriveGTR]

Lets say I was rotating my Gyro at 600 degrees per second. The sensor's output would be 8191 in decimal according to the datasheet. Now lets say that the sensor is outputing 856 in decimal format. The sensor works at 0.07326 degrees per LSB. That means 0x0000 is 0, 0x0001 is 0.07326, 0x0002 is .14652 and so on. In order to use integer math, I need to use 7326.

100000 * .07326 = 7326

7326 * 856 = 6271056

One problem is 2 digits are cut off. How do I get around this?