Final fuel sender design:
Here is a simple, one-line schematic that includes the 0-90 ohm fuel sender connected to the Pixhawk RPi CM4 Baseboard with a noise filter capacitor and voltage divider:
Hi @SJohnson - still have an issue when turning left/right. The servos are pretty agressive, but only in a turn. When pushing the stick forward, they move at a “normal” rate. I wonder if I’m looking at this wrong - maybe the “normal” rate (fore/aft) is slow, and the left/right is normal?
It makes for a bit of jerky turns. Still haven’t ran the configurator, but maybe that’s next?
Hope all is well with you and your bro - take a look at my fuel schematic and see if I missed anything. ChatGPT helped with the instructions…cd
I think your post of the fuel sensor setup is great. It looks fine to me as long as the voltage being read by the Pixhawk is always below 3.3v for all float levels in the tank. You did a great job of laying this out for others to use.
As far as steering with the RC Transmitter as long as you have set it up for exponential steering rate control, I don’t know of anything else you can do. To me steering with the transmitter has always taken a very careful touch of the stick. I am not sure what you mean by “configurator”.
I have also come a long way in deploying sensors on the original mower drive handles and putting together a system to switch between Ardupilot control and original drive handle control. I just want to actually get it working on my mower before I post the details of this system. I have redesigned the sensors twice and made a lot of changes on the overall system as I discovered improvements. My goal is to be able to flip a single switch (Switching the safety interlocks around so it is safe for a rider, disconnecting Ardupilot and enabling the manual drive system).
The gas dampeners are only connected to the handles. The only thing that they do is to keep the manual operator from moving the handles too rapidly. It keeps the operator from over steering and helps keep the mower going straight. All the gas powered zero turn mowers come with them installed. Most of the time they are under that front deck and they look like tittle shock absorbers. They have no effect on the servos as long as the original mechanical connecting rod from the handles back to the hydrostat control valve is removed. The area where the gas dampeners are located could also be another area where the handle sensor could be be connected if it is convenient on your mower.
Yes, we are totally “fly-by-wire”. The only risk to the servos is during setup of the manual control system. It’s easy to slam the servos into the stops until you get the setup (sensor rotation and min/max travel limiters setup). I ended up unplugging my servos during setup and just using the measured PWM pulse width on my cheap oscilloscope to get me setup pretty close before I plugged back in the servos.
Part of my do-no-harm strategy (to my Father-in-law’s mower) was to not drill any new holes. Went for a long time with only one (ground for the safety light on the rops), and drilled a couple more to secure the fuel tank. Sadly, I used the damper attach points for my servos.
I’m working on an idea for either a revamp of my existing setup (move the controls higher), or, a second mower where I think I’ll try the same setup. My hardware-in-the-loop testing setup is essentially the gear for another mower.
Thanks for the note - have a great holiday and I’ll see you at Mowstock (if not travelling) …
Thanks for the config @SJohnson ! I just moved my telemetry and nav antennas to the top of my ROPS hoping to alleviate a float/no fix issue, but no joy. Further I may have a problem with one of my servos. Likely self inflicted, but will start troubleshooting and see what comes up.
Re the antennas - WAY easier to manage the POS settings than my last array. . .
Great to see the upgrades and see you are still working on the mower. My antennas are up high also and the only trouble I have is tree branches once in a while, so I have to either trim the trees or stay farther back from them.
I think all mowers should have a safety light!
Having issues getting rtkfix on both gps’s. Happened before the move of the antennas - can’t seem to figure out why no worky… Your config was helpful - used mostly for tuning my turns/waypoints… Onward…
Problem - cannot reliably attain RTKfix on both GPS radios.
Work to date - moved GPS antennas as lower mounts thought to occlude parts of the sky; fiddled with GPS config settings (with ardupilot reboots in between); compared my config to @SJohnson 's (his setup is slightly different, older rev, but close); researched what I could find in ardupilot forums.
Thx for jumping in Yuri - totally appreciated. GPS1 seems to be at issue - RTK Float is the norm for that radio, but not always. In clear view of the sky and with corrections being sent for > 15min, still mostly RTK Float. This used to be my indicator that I didn’t turn on corrections and after enabling, GPS1 went to RTK Fixed. Not the case anymore.
I’ll double-check the corrections this afternoon and reply, but if memory serves, for GPS2, RTK Fixed remains with/without corrections.
Swapped radios back to original - initially RTK Fixed on both (with corrections on), but over a short time (3min) became intermittent RTK Float/Fix - mostly RTK Float.
Getting Unhealthy GPS Signal too (when not in RTK Fixed)
This feels like I’ve mucked up the configuration of one of the radios in Ardupilot/MP config. I haven’t had to touch the radios with U-Center since the first day I installed them.
Was hoping for a cabling problem - easiest for me to resolve. Anyway, if you can point me to some diagnostic tools, ie., what data labels to review in the logs would be really helpful.
