About MiguelSanches

Dear all, I am using a bmx055 and I would like to detect when the sensor is at a flat position. According to the datasheet, the ACC register 0X0C detects if the sensor is at a flat position. I am using the Arduino IDE and doing the following set of instructions to detect if the sensor is flat. writeByte(BMX055_ACC_ADDRESS, 0x16, 0x80);  //enable flag to flat detection byte c = readByte(BMX055_ACC_ADDRESS, 0x0C) & 0x80; // get byte from register, perform AND bitwise to retrieve only the flag bit.   I have been able to detect the flat position but the angle range is a bit higher than the desired. Is it possible to set the range to another value?  The register 0x2E contains the threshold if I am not mistaken, but I can't figure how to translate the range of 0 to 44.8º into the byte that fits the address  How can I detect if the sensor is at a flat position with an error of +/- 2º for example? Please advise,   Thanks, Miguel   ... View more

Dear all, Recently I have acquired a bmx055 and I having some doubts regarding the data conversion and offset compensation. According to the datasheet of the bmx055 (https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BMX055-DS000.pdf😞 1 - The fast compensation for the accelerometer must be done in the 2g range (page 31). However, if I decide to switch the range afterwards for 16g, for example, will the offset compensation still be valid? 2 - The accelerometer data is a 12 bit word for each axis, but what are the units for the raw data? I would like to convert from g's to m/s^2 and I can only found the sensitivity in LSB/g in the datasheet 3 - I was trying to implement the fast compensation offset for the gyroscope (page 85 of the datasheet) but I am having some troubles 3.1. According to the datasheet I have to enable the GYR 0x32 <0:2> bits for each axis. But can I enable all at the same time? Or do I need to one at each time like it is recommended for the accelerometer data? 3.2. Then I need to set the wordlength and enable the start bit  GYR 0x32 <3>to start the compensation right? 3.3. Once the compensation as ended the GYR 0x32 <3> bit is reset to 0, but where are the fast compensation values saved? in the GYR 0x36 register? or in the 0x37, 0x38, 0x39 (for each x, y and z axis)? If in the GYR 0x36 register should I trim and cast each axis value so that it becames a 16bit word? 4. In page 85, it is also recomended that the gyro range for fast compensation is 125º/s for higher accuracy, instead of 2000º/s. However, if I do it with the 125º/s range selected, can I later on switch to 2000º/s and still mantain the calculated offset compensation? Thank you in advance, With best regards, Miguel Sanches ... View more