PulseInOut input error margin

I am a little suprised to see as much as 200us error on reading input side. Test taken using a servo tester at neutral. Tester pretty much nails 1.49ms pwm - checked using Saleae logic. However the input reads for the PIPO module seem to be all over the place. You think this could be a sw bug in the driver and/or firmware on the board that could be fixed? As it stands, 200us± is a bit more then I expected. Thanks much.
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@ Gus

I can’t find firmware for this module. Can you guys please make it available? It would be nice if each DaisyLink module’s firmware would be available in the download tab for that module on the main site.


Good point.

I want to experiment with making a flight stabilizer like the Hobby King version. But the 200us jitter will be way too much. It should be <=5us. 8us would show jitter.

@ William - I used a netduino mini about 18 months ago and a imu to stabalize a Skywalker rc plane. The mini was fast enough to read both the serial from the imu and 4 pwm channels from the receiver on 4 io pins. Stabalized the plane a treat.

Cool. You have the project posted anywhere? tia

@ William - I haven’t really bothered documenting it - here is about the only place i posted it…


One thing that i found out with my experimentation is, don’t always believe the so called Guru’s that something can’t be done.
One thing they like to bang on about it is you MUST have PID loops and have them dialled in perfectly for your plane to fly.
Will as you can see from the link a quick and dirty if else statement worked well for me :slight_smile:

Since that post i discovered the joy of GHI and am looking at building a G120 based autopilot with waypoint navigation etc.

I just need to stop being like a Meerkat and focusing on finishing it…oooo look at that over there… :smiley:

@ Justin. Thanks. Maybe if you get a chance, you can add some comments around what the math is doing and what the domain of values is for the gyro outputs (i.e. _pitch, and _roll). Still not sure the MF will allow enouph speed to do pwm input interrupt timing on 4-6 channels and get accuracy. I thought I remember somewhere 20ms± for each interrupt. Anything over 5us will be not so good. I was hoping offloading the pwm reads to the PIPO module would solve this. I would rather miss a whole frame and have accurate pwm input values.

@ William - I will have a hunt around for the old project…
I resently tested reading 5 channels on a bee and got pretty good results.
If you want ping me an email on what you are trying to achieve as i might be similier to what I have done or about to do: Justin at ingenuitymicro dot com