There is a problem with the motor 4 signal on the Xcopter 4.7 firmware from kapteinKuk. To solve it I will post here some PWM readings I did with my logic analyser.
I used my Futaba T10 with Frsky module using a V8 7-channel receiver. The value of the throttle channel was set in the servo monitor of the TX, so I was able to set the value every time the same. I recorded the output of M1-M4 and the throttle input signals with a logic analyser, 1 million samples at 50kHz. The PWM signal had a accuracy of +-2%. I used two boards to do the first experiment:
Tested firmwares are:
PWM refresh of M1-M4: 299.4 Hz
<columns 100% 33% →
| board1 | ||||||
|---|---|---|---|---|---|---|
| TX | KK board | |||||
| Stick pos | Thr value | Thr value | M1 | M2 | M3 | M4 |
| 12% | -92 | |||||
| 25% | -62 | 1.26 | 1.12 | 1.28 | 1.10 | 1.10 |
| 50% | 0 | 1.52 | 1.38 | 1.52 | 1.34 | 1.20 |
| 75% | 63 | 1.78 | 1.62 | 1.78 | 1.60 | 1.44 |
| 100% | 125 | 2.04 | 1.88 | 2.00 | 1.86 | 1.68 |
<newcolumn>
| board2 | ||||||
|---|---|---|---|---|---|---|
| TX | KK board | |||||
| Stick pos | Thr value | Thr value | M1 | M2 | M3 | M4 |
| 12% | -92 | 1.16 | 1.08 | 1.18 | 1.08 | 1.08 |
| 25% | -62 | 1.28 | 1.14 | 1.32 | 1.10 | 1.08 |
| 50% | 0 | 1.54 | 1.38 | 1.58 | 1.38 | 1.18 |
| 75% | 63 | 1.78 | 1.64 | 1.82 | 1.60 | 1.42 |
| 100% | 125 | |||||
<newcolumn>
| board3 | ||||||
|---|---|---|---|---|---|---|
| TX | KK board | |||||
| Stick pos | Thr value | Thr value | M1 | M2 | M3 | M4 |
| 12% | -92 | 1.14 | 1.02 | 1.02 | 1.02 | 1.02 |
| 25% | -62 | 1.26 | 1.16 | 1.18 | 1.12 | 1.12 |
| 50% | 0 | 1.52 | 1.36 | 1.48 | 1.36 | 1.24 |
| 75% | 63 | 1.78 | 1.64 | 1.74 | 1.62 | 1.48 |
| 100% | 125 | |||||
</columns>
PWM refresh of M1-M4: n Hz
<columns 100% 33% →
| board1 | ||||||
|---|---|---|---|---|---|---|
| TX | KK board | |||||
| Stick pos | Thr value | Thr value | M1 | M2 | M3 | M4 |
| 12% | -92 | 1.16 | 1.02 | 1.02 | 1.02 | 1.02 |
| 25% | -62 | 1.26 | 1.22 | 1.18 | 1.18 | 1.10 |
| 50% | 0 | 1.50 | 1.48 | 1.44 | 1.42 | 1.10 |
| 75% | 63 | 1.78 | 1.74 | 1.70 | 1.68 | 1.38 |
<newcolumn>
| board2 | ||||||
|---|---|---|---|---|---|---|
| TX | KK board | |||||
| Stick pos | Thr value | Thr value | M1 | M2 | M3 | M4 |
| 12% | -92 | 1.14 | 1.12 | 1.10 | 1.08 | 1.08 |
| 25% | -62 | 1.28 | 1.26 | 1.24 | 1.20 | 1.08 |
| 50% | 0 | 1.54 | 1.50 | 1.50 | 1.48 | 1.10 |
| 75% | 63 | 1.78 | 1.74 | 1.74 | 1.72 | 1.30 |
<newcolumn>
| board3 | ||||||
|---|---|---|---|---|---|---|
| TX | KK board | |||||
| Stick pos | Thr value | Thr value | M1 | M2 | M3 | M4 |
| 12% | -92 | 1.14 | 1.02 | 1.02 | 1.02 | 1.02 |
| 25% | -62 | 1.26 | 1.12 | 1.26 | 1.12 | 1.12 |
| 50% | 0 | 1.54 | 1.34 | 1.56 | 1.30 | 1.32 |
| 75% | 63 | 1.80 | 1.62 | 1.76 | 1.58 | 1.52 |
</columns>
PWM refresh of M1-M4: 256 Hz
| board1 | ||||||
|---|---|---|---|---|---|---|
| TX | KK board | |||||
| Stick pos | Thr value | Thr value | M1 | M2 | M3 | M4 |
| 12% | -92 | 1.16 | 1.02 | 1.02 | 1.02 | 1.02 |
| 25% | -62 | 1.28 | 1.22 | 1.20 | 1.20 | 1.10 |
| 50% | 0 | 1.54 | 1.42 | 1.40 | 1.40 | 1.30 |
| 75% | 63 | 1.78 | 1.64 | 1.64 | 1.64 | 1.54 |