Jonas Skalman
Reading SenseAir LP8 CO2 sensor over bluetooth low energy
Dependencies: BLE_API mbed nRF51822
Diff: main.cpp
- Revision:
- 3:933dd59ad44d
- Parent:
- 2:d02255d8c36f
diff -r d02255d8c36f -r 933dd59ad44d main.cpp
--- a/main.cpp Mon Aug 14 20:52:48 2017 +0000
+++ b/main.cpp Fri Aug 18 18:20:41 2017 +0000
@@ -4,10 +4,8 @@
#include "LP8.h"
//Sensor and ble Configuration parameters
-#define SENSOR_TIMER 20.0 //lp8 polling interval (seconds)
+#define SENSOR_TIMER 16.0 //lp8 polling interval (seconds)
#define BLE_ADV_INTERVAL 500 //advertisment interval (milliseconds)
-#define BACKGROUND_CALIBRATION_TIME 180 //timer to do background calibration (seconds)
-
//setup ble stack
@@ -21,42 +19,58 @@
// Timers
Timer lp8Wait; //timer for sensor communication
-Timer bCalibration; //timer for background calibration
-
+Ticker lp8Timer; //timer object for sensor polling
//BLE device name and uuid list setup
const static char DEVICE_NAME[] = "SenseAir LP8";
static const uint16_t uuid16_list[] = {LP8_Service::LP8_SERVICE_UUID};
-
-//check for sensor triggering and uppdating the GattServer
+//check for sensor triggering
bool triggerSensor = false; //sensor polling flag
bool doCalibration = false; //background calibration flag
+bool initCheck = true; //check for init sensor state
-LP8_Service *lp8ServicePtr; //pointer to lp8 BLE service object
+LP8_Service *lp8ServicePtr; //
+
uint8_t ccByte = 0x20; //calculation control byte to LP8
-//**************************** ble functions *******************************
-// on Disconnect, Restart BroadCasting
+
+//**************************** ble callback functions ***************************
+// on Disconnect interupt
void disconnectionCallback(const Gap::DisconnectionCallbackParams_t *params)
{
+ initCheck = true;
//turn of sensor at ble disconnect
VBB_EN.write( 0 );
+ //cancel sensor timer
+ lp8Timer.detach();
+
//restart broadcast
ble.gap().startAdvertising();
}
-//sensor polling interupt
+//sensor polling
void triggerSensorPollingInterupt()
{
triggerSensor = true;
+
+ //reset callback timer
+ lp8Timer.detach();
+ lp8Timer.attach(&triggerSensorPollingInterupt, SENSOR_TIMER);
+
};
-//app interupt for calibration...
+
+void connectionCallback(const Gap::ConnectionCallbackParams_t *params)
+{
+ lp8Timer.attach( triggerSensorPollingInterupt, 4 );
+}
+
+//on BLE data written
void calibrationCallback(const GattWriteCallbackParams *eventData)
{
+ doCalibration = true;
ccByte = eventData-> data[0];
- doCalibration = true;
}
@@ -66,41 +80,30 @@
{
wait(1);
-
- Ticker lp8Timer; //timer object for sensor polling interupts
+ ble.init();
- //timer callback
- lp8Timer.attach(&triggerSensorPollingInterupt, SENSOR_TIMER); //trigger sensor reading every X sec
-
- ble.init();
-
- //disconnect callback
- ble.gap().onDisconnection( disconnectionCallback ); //do callback if ble disconnect
- //on data recevied callback
- ble.onDataWritten( calibrationCallback ); //trigger for calibration control
+ //callbacks
+ ble.gap().onConnection( connectionCallback );
+ ble.gap().onDisconnection( disconnectionCallback ); //
+ ble.gattServer().onDataWritten( calibrationCallback ); //
//************************ LP8 variables *********************************
- int co2Value = 400; //initial CO2 value
- double tempValue = 20.0; //init temp value
- int Vcap = 3000; //mV
- uint32_t errorFlag = 0; //error bits from lp8
+ int co2Value = 99; //initial CO2 value
+ float tempValue = 99; //init temp value
+ int Vcap = 99; //mV
+ uint32_t errorFlag = 0; //error bits from lp8
+ uint8_t sentCCbyte = 0x99;
-//************************ Checks *********************************
- bool initCheck = true; //check for init sensor state
- bool successCheck = false; //check for sensor communication
-//************************ Calculation control bytes ********************
-// uint8_t sM = 0x20; //lp8 calculation control byte using Subesquent Measurments mode
-// uint8_t bC = 0x52; //Background Calibration using unfilterd data + reset filters
+//setup LP8 object
+LP8 *lp8 = new LP8(Device, VBB_EN, RDY, Res, lp8Wait);
-
-//setup LP8 object
- LP8 lp8(Device, VBB_EN, RDY, Res, lp8Wait); //pass pins: serial, vbb, rdy, res, timer
//Setup GattService
- LP8_Service lp8Service(ble, co2Value, tempValue,
- Vcap, errorFlag, ccByte); //
- lp8ServicePtr = &lp8Service; //
+// LP8_Service lp8Service(ble, co2Value, tempValue,
+ // Vcap, errorFlag, ccByte, sentCCbyte);
+ lp8ServicePtr = new LP8_Service(ble, co2Value, tempValue,
+ Vcap, errorFlag, ccByte, sentCCbyte); // lp8Service;
// setup ble advertising parameters
@@ -109,7 +112,7 @@
ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LOCAL_NAME, (uint8_t *)DEVICE_NAME, sizeof(DEVICE_NAME));
ble.gap().setAdvertisingType(GapAdvertisingParams::ADV_CONNECTABLE_UNDIRECTED);
ble.gap().setAdvertisingInterval(BLE_ADV_INTERVAL); /* advertising interval in ms. */
- ble.gap().startAdvertising(); //start broadcast
+ ble.gap().startAdvertising();
// Wait for initialization to complete.
while (ble.hasInitialized() == false) {
@@ -121,41 +124,40 @@
//*************************** start the main loop ***********************************
while ( true )
{
+
if(triggerSensor && ble.gap().getState().connected ) //trigger when timer interupts and there is an established ble connection
{
if ( initCheck ) {
-
- successCheck = lp8.lp8Init(); //initialize talking with the lp8 (first call on startup)
-
- if ( successCheck ) {
- initCheck = false;
- }
+ lp8->responsePurge(50); //purge buffer
+ if ( lp8->lp8Init() != true ) {
+ //initCheck = true;
+ }
+ else {
+ initCheck = false;
+
+ }
+ }
+
+ else if ( lp8->lp8Talk( ccByte ) != true ) {
+ //restart with init sequence if sensor state is lost or communication fails
+ initCheck = true;
+ ccByte = 0xff; //app error flag
}
-/*
- else if ( doCalibration && ccByte == bC ){
- lp8.lp8Talk( bC ); //do background calibration
- bCalibration.start();
- if( bCalibration.read() >= BACKGROUND_CALIBRATION_TIME ){
- bCalibration.stop();
- bCalibration.reset();
- doCalibration = false;
- ccByte = 0xff;
- }
- }
-*/
- else {
- lp8.lp8Talk( ccByte ); //Communication with lp8, pass Calculation control byte
- }
-
+
//reset polling check
triggerSensor = false;
- //update the gattServer
- lp8ServicePtr->updateCo2Value( lp8.getValue() ); //get CO2 value
- lp8ServicePtr->updateTempValue( lp8.getTempValue() ); //
- lp8ServicePtr->updateVcapValue( lp8.getVcapValue() ); //
- lp8ServicePtr->updateError( lp8.getErrorStatus() ); //
- lp8ServicePtr->updateDataWritten( lp8.getCCbyte() ); //send back the calculation control byte that was used in LP8 measurement
+ //update the gattServer characteristic values
+ lp8ServicePtr->updateCo2Value( lp8->getValue() ); //get CO2 value
+ lp8ServicePtr->updateTempValue( lp8->getTempValue() ); //
+ lp8ServicePtr->updateVcapValue( lp8->getVcapValue() ); //
+ lp8ServicePtr->updateError( lp8->getErrorStatus() ); //
+ lp8ServicePtr->updateDataWritten( lp8->getCCbyte() ); //send back the calculation control byte that was used in LP8 measurement
+ lp8ServicePtr->updateReWrite( ccByte );
+
+ //reset calibration control
+ ccByte = 0x20; /* resets to 0x20 (subs. talk) after one sample.
+ Check lp8Talk() function. */
}
else { ble.waitForEvent(); } //ble save energy