Ok All,
This is my second attempt to get this working right. I just received my second Ardupilot board, the first I am sure I had an ESD that cooked the MUX. With experience behind me and the second board in front of me I proceeded to assemble the board as per the instructions in the wiki, including installing the jumper wires on the back of the board. I powered the Ardupilot board through the ESC, and ran the test code loaded at the factory (blinking yellow LED). I checked the radio and receiver separately (a new Futaba T7C FASST2.4Ghz), along with the servos speed control and the motor. All the radio gear checked out OK. Then I loaded the radio_test from the Test Suite onto the Ardupilot board. At this point I opened the serial window and observed the stream of PWM values coming in for CH1, CH2 and CH3. The readings were as follows:
MS:20 CH1: 1108-1934 CH2: 1105-1928 CH3: 981
Both CH1 and CH2 responded normally, CH3 showed no movement despite the fact the motor responded accordingly. I double checked all my connections, and rechecked my solder joints (especially CH3 to PIN D13).
What am I doing wrong? I'm positive I didn't have a repeat ESD. I need help here, any suggestions would be welcome. Especially the right one!
BTW for those who read my post Uh-Oh! Don't try this at home! Good news I got the connector soldered back on! See the attached picture.
Additional observation, I was just about to give another go at this.This time as I was setting up to load the code again, I plugged the FTDIcable in before I plugged in the ESC. When I plugged the FTDI cable inthe red power LED on the Ardupilot came on. It was my understanding fromreading the wiki that the Ardupilot board shouldn't get power from theFTDI cable.
"We did not connect the power pins on the FTDI port to the processor toavoid power conflict when the board is powered by the Rx and you areusing the FTDI as a serial monitor)."
I just uploaded the radio_test sketch to my old Ardupilot board (the onewith the bad MUX), and the red power LED only comes on when the ESC isconnected to CH3 out. I don't know if I can trust this as a validcomparison though, as I don't know the full extent of the damage fromthe ESD to that board.
Ran the switch_test, all checks out ok!
Ran the throttle_test, results mirror above Radio_test results, with the addition that the CH1 and CH2 values are fluctuating on their own without any user input.
Interestingly the power issue with the FTDI cable went away after plugging in the ESC and turning on the power. Now when I unplug the ESC and only have the FTDI cable plugged in, the power LED stays off.
Not sure what to do here, anyone able to offer any insight?
Replies
I've made a special version of the radio test that moves the input to PIN 11 instead of the problematic PIN 13.
If you are still having trouble, move your jumper from 13 to 11 and try this version.
Jason
Arudpilot_26_radio_test_11.zip
The red wire from your FTDI cable is 5v and is enough to power servos. I always add a jumper from the red pin (labeled Vcc) to the + pin of one of the servo ins or outs. Usually pin 4. This requires that I NEVER connect the ESC/battery and the FTDI cable at the same time, but it saves me a lot of hassle and I've never fried a board.
Jason
Here's my output:
MS: 20 ch1:1555 ch2:1498 ch3:1094
I've attached the most recent radio test using exactly the same code as 2.6. I'll post it later to the downloads.
The ch3: value that you're seeing is the default value, so you are somehow not triggering the interrupts in the 328. This is most likely a voltage issue as low voltage to this pin will prevent it from capturing.
Jason
Arudpilot_26_radio_test.zip
I'm not sure what's going on with your throttle. I've got dozens of these boards and have never seen that problem. I'm thinking it might be due to a undervoltage RC receiver. What RC gear are you using? If it's under 3v, you might need to use a servo amp on the throttle channel. I've got a few spare ones and can send you one if you'd like.