Battery Level measurement of nrf52832 using ADC and sending it over BLE mesh

RE: Battery Level measurement of nrf52832 using ADC and sending it over BLE mesh

tesc — Thu, 20 Apr 2023 14:12:15 GMT

HI,

I do not see anything immediately wrong with any of that, although it does not cover all the details so I cannot say for sure.

For instance, if the value pointed to by the rsp argument to bat_get_value() resides in a stack frame that gets popped and overwritten before the value is sent, then some bogus data from a different function may be what is actually sent over-the-air.

You could for instance try printing from within bat_get_value(), after rsp has been filled using sensor_value_from_double() and before returning from that function, and compare that to the value actually getting received in the other end. If it changes in-between, then you may have a dangling pointer.

Regards,
Terje

RE: Battery Level measurement of nrf52832 using ADC and sending it over BLE mesh

AdityaN — Mon, 03 Apr 2023 14:57:35 GMT

Hey,

i am using sensor sever model,

static struct bt_mesh_sensor bat_val = {
	.type = &bt_mesh_sensor_present_input_voltage,
	.get = bat_get,

};

I've registered a callback function called as bat_get()

static int bat_get(struct bt_mesh_sensor_srv *srv,
			 struct bt_mesh_sensor *sensor,
			 struct bt_mesh_msg_ctx *ctx,
			 struct sensor_value *rsp)

this callback function calls a function which is actually responsible for reading ADC values

int bat_get_value(struct sensor_value *rsp) {
	int reading = readAnalog_bat();
	double volt = reading/1000.0;
	sensor_value_from_double(rsp,volt);
	return 0;
}

the function readAnalog_bat() returns the value in mV.

I also tried publishing values manually by using the following function

void bat_pub()
{
	int err;

	struct sensor_value val = {
		.val1 = 0,
		.val2 = 0
	};
	bat_get(&sensor_srv, &bat_val, NULL, &val);
	err = bt_mesh_sensor_srv_pub(&sensor_srv, NULL, &bat_val, &val);

	if (err) {
		printk("Error publishing battery (%d)\n", err);
	}
}

let me know if you need anything else

RE: Battery Level measurement of nrf52832 using ADC and sending it over BLE mesh

tesc — Mon, 03 Apr 2023 09:20:44 GMT

Hi,

Please note that mesh model implementations typically have callback functions that you must write and register, for providing the model with the values. What mesh models are you using for sending the values, and what code do you have for providing the value to the mesh library and/or for sending the messages?

Regards,
Terje