I seem to have a problem with my MinimOSD setup.
When I connect my MinimOSD to the APM2 board I get the following message: "Waiting for Mavlink Heartbeats". The message never goes away as far as I can tell.
My setup is as follows:
APM2 board bought new from the store here
MinimOSD board bought new from the store here
CMOS camera bought new from the store here
EagleTree Eagle Eyes ground station that I've used for about a year.
Everything seems to work flawlessly meaning that I can hook up the APM2 to the camera and an external power supply and receive video on my FatShark goggles connected to the Eagle Eyes.
I am using 900MHz for my video feed and I am not using any of the XBee components.
I've searched the forums here and this is what I have done so far:
-I've downloaded the ARDUCam OSD configuration utility and through that I have updated the firmware and the character set.
-I've updated the APM2 board to the newest firmware (ARDUPlane 2.33) and I am using Mission Planner version 1.1.67 which is current as of this morning.
-I've gotten into the MP and downloaded the logs and then reset the board.
-I've followed this post on here and reset my values on SR3 to the ones shown: http://diydrones.com/profiles/blog/show?id=705844%3ABlogPost%3A7521...
-I've replaced the connecting cables in case I had a bad one.
So far nothing has worked other than I'm getting a really nice picture using this setup! :-) No interference that I can see. I'll even go as far as ordering a new MinimOSD but they're sold out right now so that's not an option.
Thanks for looking! If it helps I'll send a candy bar to whoever comes up with a winning suggestion. :-)
Ok, the basics are that the OSD boards (doesn't matter which "brand"), plugs into the same serial port from the ardupilot as your telemetry modem (Xbee, the new ones or any wireless bridge setup). The OSD board really only needs to receive, where the modem will both transmit and receive. The bottom line is that you screwed up the wiring. Whatever you connected is either shorting that serial out, and/or you did not connect the modem solution correctly.
Both boards (OSD and Modem) more or less get connected in parallel with each other to the serial port. (Think like a y splitter). The OSD receives the exact same packets as mavlink thus you might not be getting any data on either one.
The picture says some important info, "DO NOT CONNECT TX when using with Xbee"
So recap: the only wires from the APM to the OSD will be 5v, gnd, and RX, but the Xbee is also conenct to the APM normally with all 4 wires , 5V, GND, RX, TX!!!
Thanks for the replies!
I've read through the posts you've linked and have tried what you have suggested but I still get the same "Waiting for MAVLink Heartbeats..." message.
You can even remove the Tx and Rx wires and the video will still work but you will still receive the message.
I've tried Tx on the OSD to the Rx on the APM as well as the reverse of that.
I've tried Tx to Tx and Rx to Rx as well.
Any more suggestions?
So, at the end of the day I'm happy to say that I got this solved! I'm going out to buy myself a candybar!
I was doing a couple of things wrong but the main two were that I was bench testing using power over the USB to power the APM (I was also using a battery to power the camera as specified in the Wiki drawings.), and I was only linking the APM to the MinimOSD with no other servos connected.
To fix all of this I mounted the APM/MininOSD assembly into a plane, plugged in the servos and esc to the APM, the APM connections into the Rx, connected the MinimOSD, and then the camera and Tx to the MinimOSD and fired it all up. It worked!
The connections I made between the MininOSD and the APM were:
APM +5 to MininOSD +5
APM GND to MinimOSD BLK
APM Tx to MinimOSD Rx
I'm not sure about the APM GND to MinimOSD BLK though, the photos in the Wiki show this connection but I'm wondering if the GND on the OSD would be better?
I hope this helps someone else!
Ok, more testing!
It's just the connection of the USB cable that causes this.
Am I the only one that has ever had this problem? :-)
FYI, when using USB power, some sections of the APM are not powered and it's possible you just happened to use those pins are part of your OSD power scheme. The reasoning is that USB only can provide about 500ma of 5V power and thus backfeeding the ESCs, servo outputs and a number of things could cause a brownout or the USB port to just shut down. APM 2 has at least one diode just for this purpose such that USB will not feed the ouputs 5 volt rail.
So somewhat the answer is yes, other people have experienced problems when running from USB only when they did not know the limits of what's powered and not. Sorry I don't have the specific of what's powered and not, but it shouldn't be too hard to test and see no output on the 5V rails rather quickly.