dgatf
Support for more than 1 NTC sensor
I fly a big gasser that have 2cylinder engine. I can se the value of having more than one ntc value, And also be able to pickup rpm value from the electronic ignition systems from like an Da or Dle engines that are popular brands. Or maybe having an separate magnetic pickup for rpm measument. maybe thats alreade possible by using the pwm option
Yes, you can use ESC Protocol -> PWM to read rpm in PWM or pulses format. Note that I've just added support for pulses (not only PWM). You may need to download binaries if the output are pulses.
Which radio system are you using? Depending on it, it is may be possible to use two MSRC boards to get two ntc readings. AFAIK, you can do this with Smartport (x28), Jeti (x2) and SRXL2 (x16).
Yes, allowing to select analog inputs for each analog pin is in the TODO list. Implementing this is really extensive.
I am using Frsky and smartport, i didnt even think about running 2 boards. I will have to try that.
Yes, you only need to select a different Sensor Id in receiver protocol for each MSRC board. Connect both to Smartport.
Electronic ignition systems from like an Da or Dle
Do they output rpms in pulses or PWM or they use another protocol?
I may have been wrong about the Da engines, it seems that they do not have rpm output from the ignition system so you would have to ad and extra hall sensor pickup to the "flywheel" if you can call it that. small tread about it here: https://www.flyinggiants.com/forums/showthread.php?t=87090
And about the signal from DLE an similar it seems to be "RCEXL ignition outputs the same 0-5 vdc square wave" I found it in this tread: https://www.flyinggiants.com/forums/showthread.php?t=325195#post3149473
I myself are running an ZDZ engine without an extra lead so for me its the extra pickup way to go.
There is an advanced engine suite for frsky but i thinks its a bit heavy and have alot of unnessesary functions.
I will try going with double boards and se how it works, i only have one smartport lead from the engine compartment but i think it should work anyway right,
Thx for all the tips.
Best regards Jonas
I will try going with double boards and se how it works, i only have one smartport lead from the engine compartment but i think it should work anyway right
You can use a servo splitter (Y connector).
Some update on this, it took some time but i built a small "unity" crammed together connected with pins on the appropiate places, and a small bec in between to get the voltage down because i run 7v I have gotten both the temp sensors to work (it works really good). but i cant get the rpm sensor to work. I have checked the sensor and it is an hal sensor that drops its resistance to zero when passing the magnet on the flywheel. I am unsure if i need some pickup resistor on the board side? , or even were to connect it. on the pictures it seems like it should be pin 6 but in the documentation i think it points to pin 4 but really unsure here. Best regards /Jonas
Yes, there was a mistake in the circuit image. PWM or pulses goes to GPIO4. Fixed with commit 02951b1.
It uses the internal pullup of the RP2040 (50k).
You should see in the log:
Esc PWM (98) < Rpm: 2991
Esc PWM (98) < Rpm: 2990
Esc PWM (98) < Rpm: 2990
If the pulses are not detected you may need to add an external pullup from 3k to 10k.
hall sensor that drops its resistance to zero when passing the magnet on the flywheel
Or you may need to use a pull down resistor. When resistance goes to zero, does it set the output high or low?
Maybe I should add an option to select internal pullup, pulldown or nothing.
i dont know how to check status of the output? But i will check the logs and try both alternatives if it dosnt work. I understand the basics of pullups and pulldowns but it is at the edge of my knowledge right now :-P
Which hall sensor model is? Do you have the datasheet?
If it uses a NPN transistor, you need a pullup. For a PNP transistor you need a pulldown.
Usually hall effect sensors use NPN.
No sorry i dont have any specs, its completely sealed in plastic, i "borrowed" it from an other engine.