Issues working with lis2dh12 in FIFO mode

RE: Issues working with lis2dh12 in FIFO mode

Aviv Okon — Sun, 22 Mar 2020 09:11:49 GMT

I was able to solve this issue

what I failed to understand was what the watermark interrupt meant. after speaking to a co-worker who used a similar device, we realized that the correct method of operation is to use the watermark interrupt, not the FIFO overrun interrupt. this results in the FIFO never getting full, and thus never needing to be reset

however, this also requires that only a part of the FIFO is read every time, resulting in more frequent interrupts and reads, so this is something to consider

feel free to close this, though if someone would be able to explain how to properly reset the FIFO with the nRF driver, that would also help

RE: Issues working with lis2dh12 in FIFO mode

Aviv Okon — Thu, 19 Mar 2020 08:40:56 GMT

thanks for the explanation

I'll have to dive into this and test it

I'll update after I've had some time to go through it

RE: Issues working with lis2dh12 in FIFO mode

Nguyen Hoan Hoang — Thu, 19 Mar 2020 06:56:55 GMT

The code Mojo showed you is a generic lis2dh12 driver. It works with both i2c and spi. It works with any mcu from nRF5x series to STM32.

Here is how to use with i2c.

static const I2CCFG s_I2cCfg = {
	.DevNo = I2C_DEVNO,
	.Pins = {
		{I2C_SDA_PORT, I2C_SDA_PIN, I2C_SDA_PINOP, IOPINDIR_BI, IOPINRES_PULLUP, IOPINTYPE_NORMAL},	// SDA
		{I2C_SCL_PORT, I2C_SCL_PIN, I2C_SCL_PINOP, IOPINDIR_OUTPUT, IOPINRES_PULLUP, IOPINTYPE_NORMAL},	// SCL
	},
	.Rate = 100000,
	.Mode = I2CMODE_MASTER,
	.MaxRetry = 5,
};

I2C g_I2c;

static const ACCELSENSOR_CFG s_AccelCfg = {
	.DevAddr = LIS2DH12_I2C_DEVADDR,
	.OpMode = SENSOR_OPMODE_CONTINUOUS,
	.Freq = 10000,
	.Scale = 2,
	.bInter = true,
};

AccelLis2dh12 g_Accel;

void main()
{
   g_I2C.Init(s_I2cCfg);
   g_Accel.Init(s_AccelCfg, &g_I2C);
}

To use with SPI, replace the I2C object with SPI object. As simple as that.

That driver works with fifo mode. you can cherry pick the code you need.

Other example using an Invensense IMU and stream it to Thingy App using the same SPI & I2C interface object.

github.com/.../BlueIOThingy

Other sensor example including BMI160 with same SPI, I2C interface.

https://github.com/IOsonata/IOsonata/blob/master/exemples/sensor/mot_sensor_demo.cpp

You can browse the repo for more examples

RE: Issues working with lis2dh12 in FIFO mode

Aviv Okon — Thu, 19 Mar 2020 06:07:56 GMT

what exactly is that code? I don't see any documentation there.....

Is that module controlling the accelerometer directly, without the need of the TWI\SPI interface?

which interface is used here? where are the pins configured?

have you ever seen this used on an nRF card? because I can't see which drivers this is using, and it doesn't really look like plug and play drivers would work on such systems.......

RE: Issues working with lis2dh12 in FIFO mode

Mojo — Wed, 18 Mar 2020 17:15:58 GMT

try this https://github.com/IOsonata/IOsonata/blob/master/src/sensors/accel_lis2dh12.cpp