Hi everybody,
With a friend, we've built a dyno for GoKart engines. Engines are mounted on a frame and linked to a big roller inertia. We measure roller speed thanks to a hall sensor in front of a toothed wheel, that gives a square wave. For the moment, this square wave is read by a National Instrument PCI-6010 card. Thanks to its 32bit/80Mhz counter, we have duration between each tooth. We do calculations after on PC to have torque/power curves.
The NI PCI card is very powerful for us because we can easily acquire each tooth period during 2 or 3 min (short acceleration + long deceleration) from a roller rotating at up to 3600rpm (up to 3.6khz square wave frequency with a 60 toothed wheel) without any loss of data.
I'm a little familiar with arduino because I've done classic noob stuff like playing with lcds, sd card, RTC, timers, interrupts, 7segments... I've never played with teensy (but a 3.6 is travelling to home ). I have in my mind that it would be possible to transform our expensive NI card into an arduino or a teensy.
Can you give me some advices before attempting the impossible for a man who can learn, but who plays electronic just at home, my knowledge are limited.
2 philosophy :
- serial/usb is fast enough to transmit data in live, and the save is done on pc directly. but i've read here and there that pc software could limit performances?
- Or, I log in the microSD card of the teensy/arduino board, and at the end of the test, i transfer the log (automatically would be welcome) to do calculations.
Specifications of the daq :
- Tooth period measurement : as i said, worst case = 3.6khz during 3min of a 16Mhz/16bits counter value, 20 or 24bits would be better to measure low speed/high tooth period. Can I easily extend the 16bit embedded counter with the overflow information?
- Also, but less sensitive, log of 5 analog voltages at 20hz around. It's usefull to record temperature sensor (for exhaust and water, and others),
- In parallel, if microSD card option, transmit via usb/serial at 20hz, the roller speed (or tooth period) + 5 analog voltages to have a look, in live on PC screen, on the state of the dyno.
-of course there will be an input by button and serial command, to start and stop the recording.
Bonus :
-lcd/oled auxiliary screen on the dyno to display rpms/temperatures to the operator,
-PID output to drive an eddy current brake (we don't have it for the moment), with it's force sensor measuring associated.
Is this doable on teensy, or arduino? I think yes because I've seen different threads on usd card logger with very high frequency, but less results on serial fast transmission.
Thanks in advance.
Loic
With a friend, we've built a dyno for GoKart engines. Engines are mounted on a frame and linked to a big roller inertia. We measure roller speed thanks to a hall sensor in front of a toothed wheel, that gives a square wave. For the moment, this square wave is read by a National Instrument PCI-6010 card. Thanks to its 32bit/80Mhz counter, we have duration between each tooth. We do calculations after on PC to have torque/power curves.
The NI PCI card is very powerful for us because we can easily acquire each tooth period during 2 or 3 min (short acceleration + long deceleration) from a roller rotating at up to 3600rpm (up to 3.6khz square wave frequency with a 60 toothed wheel) without any loss of data.
I'm a little familiar with arduino because I've done classic noob stuff like playing with lcds, sd card, RTC, timers, interrupts, 7segments... I've never played with teensy (but a 3.6 is travelling to home ). I have in my mind that it would be possible to transform our expensive NI card into an arduino or a teensy.
Can you give me some advices before attempting the impossible for a man who can learn, but who plays electronic just at home, my knowledge are limited.
2 philosophy :
- serial/usb is fast enough to transmit data in live, and the save is done on pc directly. but i've read here and there that pc software could limit performances?
- Or, I log in the microSD card of the teensy/arduino board, and at the end of the test, i transfer the log (automatically would be welcome) to do calculations.
Specifications of the daq :
- Tooth period measurement : as i said, worst case = 3.6khz during 3min of a 16Mhz/16bits counter value, 20 or 24bits would be better to measure low speed/high tooth period. Can I easily extend the 16bit embedded counter with the overflow information?
- Also, but less sensitive, log of 5 analog voltages at 20hz around. It's usefull to record temperature sensor (for exhaust and water, and others),
- In parallel, if microSD card option, transmit via usb/serial at 20hz, the roller speed (or tooth period) + 5 analog voltages to have a look, in live on PC screen, on the state of the dyno.
-of course there will be an input by button and serial command, to start and stop the recording.
Bonus :
-lcd/oled auxiliary screen on the dyno to display rpms/temperatures to the operator,
-PID output to drive an eddy current brake (we don't have it for the moment), with it's force sensor measuring associated.
Is this doable on teensy, or arduino? I think yes because I've seen different threads on usd card logger with very high frequency, but less results on serial fast transmission.
Thanks in advance.
Loic