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Hello, I am wanting to display MPG on an old VW camper van. Does anybody know of a hall effect flow sensor that can report the very low flows found in carburetors please.

terryrow last edited by

Hello, I am wanting to display MPG on an old VW camper van. Does anybody know of a hall effect flow sensor that can report the very low flows found in carburetors please. Alternative suggestions always welcome.
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arden last edited by

guess no odb port?
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mpg meter for vw camper van 1

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I have success! (oops, that's suppose to be Timer1) I only sample for 1/60 of a second. What I did was to back up all the timer registered I used and then resorted them after I was done sampling. (As opposed to initializing the registers in setup and then starting the timer when needed.) Now I have a Nano sampling the data and sending it to a MySensors Gateway on an RPi3B+ which then sends it to an MQTT broker runing on an old laptop. Also running on the laptop is Home Assistant running inside of VirtualBox. If MySensors does use Timer1, it appears that restoring the registers allows it to be shared. //------------------------------------------------------ISR ISR(TIMER1_OVF_vect){ // interrupt service routine for overflow TCNT1 = TimerPreloadValue; // must be first line! starts the timer counting again digitalWrite(TRIGGER_START_SAMPLE_PIN,HIGH); samplesVolts[--sample]=analogRead(VOLTS_IN_PIN); // decrement before capturing samplesCurrent[sample]=analogRead(CURRENT_IN_PIN); digitalWrite(TRIGGER_START_SAMPLE_PIN,LOW); if (!sample){ // count down to zero digitalWrite(TRIGGER_START_SAMPLE_PERIOD_PIN,LOW); // indicate that sampling is complete samplingEnd = micros(); TCCR1B &= 248; // turns off timer } } //------------------------------------------------------sampleOneCycle void sampleOneCycle(){ // back up timer registers uint8_t TCNT1_b = TCNT1; uint8_t TCCR1B_b = TCCR1B; uint8_t TCCR1A_b = TCCR1A; uint8_t TIMSK1_b = TIMSK1; // configure timer which starts the sampling noInterrupts(); // disable all interrupts TCCR1A = 0; TCCR1B = 0; TCNT1 = TimerPreloadValue; // preload timer //TCCR1B |= (1 << CS10)|(1 << CS12); // 1024 prescaler TCCR1B &= 248; // turns off timer? TIMSK1 |= (1 << TOIE1); // enable timer overflow interrupt ISR // demark sampling sample = NUMBER_OF_SAMPLES; // count down to zero digitalWrite(TRIGGER_START_SAMPLE_PERIOD_PIN,HIGH); samplingStart = micros(); TCNT1 = 65535; // first trigger right away! TCCR1B |= 1; // turns on timer interrupts(); // enable all interrupts // wait for sampling to be complete while(digitalRead(TRIGGER_START_SAMPLE_PERIOD_PIN)){}; samplingEnd = micros(); // restore timer registers TCNT1 = TCNT1_b; TCCR1B = TCCR1B_b; TCCR1A = TCCR1A_b; TIMSK1 = TIMSK1_b; }
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Hello, I am wanting to display MPG on an old VW camper van. Does anybody know of a hall effect flow sensor that can report the very low flows found in carburetors please.

Suggested Topics

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Hardware • mysensors interrupt nano interrupts esp • • OldSurferDude

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hlk-pm01 are to noisy for rfm69?
Hardware • • Tmaster

Best VOC sensor for detecting a wide range of VOC's?
Hardware • • NeverDie

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Hardware • • NeverDie

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Hello, I am wanting to display MPG on an old VW camper van. Does anybody know of a hall effect flow sensor that can report the very low flows found in carburetors please.

Suggested Topics

Over the air updates General Discussion • • ToSa

Does MySensors require Arduino Timer 2? Hardware • mysensors interrupt nano interrupts esp • • OldSurferDude

Sensors and more Hardware • • Robert Leverett

hlk-pm01 are to noisy for rfm69? Hardware • • Tmaster

Best VOC sensor for detecting a wide range of VOC's? Hardware • • NeverDie

Best time of year to buy higher quality small project solar panels? Hardware • • NeverDie

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Over the air updates
General Discussion • • ToSa

Does MySensors require Arduino Timer 2?
Hardware • mysensors interrupt nano interrupts esp • • OldSurferDude

Sensors and more
Hardware • • Robert Leverett

hlk-pm01 are to noisy for rfm69?
Hardware • • Tmaster

Best VOC sensor for detecting a wide range of VOC's?
Hardware • • NeverDie

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Hardware • • NeverDie

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