Hello,
I need to power a massive 1/4 scale servo that needs 5VDC and standard PWM control. I love the Maestros, have been using them for years.
I need to know if I can connect the Maestro and the servo to a single 5VDC (70 A) power supply.
If so, does this wiring diagram look OK?
Thank you!
Please check the ground situation
Hello.
It should generally be fine to power the Maestro and servo from the same supply. In that kind of setup, the Maestro and servo should share a common ground connection. I am not sure why you have the ground rail on the Maestro connected to the AC ground on your power supply (that should not be necessary, but it’s probably okay to do), but please note that all of the grounds on the Maestro are connected internally (i.e. the GND pin for the VIN power is also connected to the GND rail for servo power).
The other potential concern would be noise or voltage dips; since the Maestro’s minimum operating voltage is 5V, and you’re right at that minimum voltage, it might be possible for the servo to draw enough current from the supply to cause the voltage to dip enough to cause the Maestro to brown-out and reset.
Brandon
Hi Brandon,
To be clear the only grounds that need to be connected are the Maestro to the servo, correct? So I am absolutely clear here’s the last stupid question: the ground for the servo is the black lead, correct? That would mean that I would need to connect that to the ground on on the Maestro AND the -5V black terminal on the DC supply, right? Just checking.
Thanks!
Servos can have different coloring schemes for their wires, but they usually use either white,red, black or orange, red, brown with black and brown being the ground wires, respectively. If your servo uses a different color scheme (or if you just want to be extra careful), I recommend checking the manufacturer’s documentation.
The Maestro, the servo, and the power supply should all have a common ground. The “negative” terminal on your power is very likely a ground connection (and not actually some -5V rail), in which case, you can make your ground connection there. (The separate green ground terminal should correspond to the ground on the AC side, meaning you can leave it disconnected to have isolated outputs on your power supply or connect it to the black terminals to share a common ground between AC and DC.) You can double check this by measuring the voltage between the negative and positive terminals with a multimeter; if you see 5V across them, then it is a ground, but if you see 10V across them, it is a negative voltage source.
Brandon
Thanks!
Quick Q: using a relay to trigger a sequence in a 24 channel Maestro. The manual says channel 18,19, and 20 can be used without having to install an external pull-up resistor. It says in channel settings to enable the internal pull-up resistor…but all I can see is the option to make that channel an “input”. Does that automatically enable the resistor or do I need to do something else?
Thanks!
After configuring them as inputs you will need to enable the “Enable pull-ups on channels 18-20” option, which is located at the bottom of the servo channel list:
Brandon
Thank you sir!
Last quick question:
I’m getting a “Error applying parameters. REPEAT must end a BEGIN…REPEAT block”
Do you see the problem? I need a second pair of eyes!
### Sequence subroutines: ###
begin
trigger18 if # Sequence 0 endif
repeat
sub trigger18
0 get_position 500 less_than #trigger18 is ch18 on maestro
return
# Sequence 0
begin
1500 6400 6559 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 frame_0..17_19..23 # Frame 0
2300 4276 5791 frame_0_1 # Frame 1
1500 4731 6051 frame_0_1 # Frame 2
1500 4224 frame_0 # Frame 3
3000 4498 5744 frame_0_1 # Frame 4
1500 4224 6134 frame_0_1 # Frame 5
1800 6400 6712 frame_0_1 # Frame 6
1500 5576 6559 frame_0_1 # Frame 7
2200 6135 6334 frame_0_1 # Frame 8
1500 6400 frame_0 # Frame 9
2000 5755 6004 frame_0_1 # Frame 10
2000 5312 frame_0 # Frame 11
2100 4952 frame_0 # Frame 12
1500 4646 6334 frame_0_1 # Frame 13
1500 5090 frame_0 # Frame 14
1500 5259 6464 frame_0_1 # Frame 15
2500 4477 6346 frame_0_1 # Frame 16
2000 4224 6039 frame_0_1 # Frame 17
1500 6665 frame_1 # Frame 18
1500 4900 6948 frame_0_1 # Frame 19
2600 6019 6783 frame_0_1 # Frame 20
1500 6304 6913 frame_0_1 # Frame 21
2300 5671 6204 frame_0_1 # Frame 22
2200 4952 frame_0 # Frame 23
2600 4424 6075 frame_0_1 # Frame 24
1500 4657 frame_0 # Frame 25
1500 4308 5673 frame_0_1 # Frame 26
1500 4224 frame_0 # Frame 27
1200 6019 6594 frame_0_1 # Frame 28
2200 6326 frame_0 # Frame 29
1200 6400 frame_0 # Frame 30
1500 5037 frame_0 # Frame 31
2200 4435 6098 frame_0_1 # Frame 32
1500 4224 frame_0 # Frame 33
1500 6283 6547 frame_0_1 # Frame 34
2500 6030 6216 frame_0_1 # Frame 35
2500 5026 frame_0 # Frame 36
1500 4572 6346 frame_0_1 # Frame 37
2000 5702 frame_0 # Frame 38
3000 6936 frame_1 # Frame 39
repeat
sub frame_0..17_19..23
23 servo
22 servo
21 servo
20 servo
19 servo
17 servo
16 servo
15 servo
14 servo
13 servo
12 servo
11 servo
10 servo
9 servo
8 servo
7 servo
6 servo
5 servo
4 servo
3 servo
2 servo
1 servo
0 servo
delay
return
sub frame_0_1
1 servo
0 servo
delay
return
sub frame_0
0 servo
delay
return
sub frame_1
1 servo
delay
return
Hello.
It looks like your ENDIF command is commented out. For reference, in the Maestro scripting language an IF command must be “closed” by an ENDIF command (and if applicable, an ELSE command should be between them. For example:
trigger18 if # Sequence 0
#code here will run if trigger18 returns true
else
#code here will run if trigger18 returns false
endif
Brandon
The incompetence is strong in me! So instead of buggin you I asked GROK A.I. to help. I fed it the whole Maestro PDF manual. It processed it and gave me this working script:
begin
check_initial # Check if relay is initially closed
if
debounce_and_recheck # Debounce and recheck the relay
if
run_sequence # Run the sequence
wait_for_release # Wait for relay to release
endif
endif
10 delay # Small loop delay
repeat
sub check_initial
18 get_position # Get initial reading
500 less_than # True if < 500 (relay closed)
return
sub debounce_and_recheck
50 delay # Debounce for 50 ms
18 get_position # Recheck after delay
500 less_than # True if still < 500
return
sub run_sequence
Vanguard_part1 # Frames 0-9
Vanguard_part2 # Frames 10-19
Vanguard_part3 # Frames 20-29
Vanguard_part4 # Frames 30-39
return
sub wait_for_release
begin
18 get_position 500 greater_than # Check if high
if
50 delay # Debounce release
return # Exit when relay is released
endif
10 delay # Small loop delay
repeat
sub Vanguard_part1
# Frames 0-9
1500 6400 6559 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 frame_0..17_19..23 # Frame 0: restored to full values
2300 4276 5791 frame_0_1 # Frame 1
1500 4731 6051 frame_0_1 # Frame 2
1500 4224 frame_0 # Frame 3
3000 4498 5744 frame_0_1 # Frame 4
1500 4224 6134 frame_0_1 # Frame 5
1800 6400 6712 frame_0_1 # Frame 6
1500 5576 6559 frame_0_1 # Frame 7
2200 6135 6334 frame_0_1 # Frame 8
1500 6400 frame_0 # Frame 9
return
sub Vanguard_part2
# Frames 10-19
2000 5755 6004 frame_0_1 # Frame 10
2000 5312 frame_0 # Frame 11
2100 4952 frame_0 # Frame 12
1500 4646 6334 frame_0_1 # Frame 13
1500 5090 frame_0 # Frame 14
1500 5259 6464 frame_0_1 # Frame 15
2500 4477 6346 frame_0_1 # Frame 16
2000 4224 6039 frame_0_1 # Frame 17
1500 6665 frame_1 # Frame 18
1500 4900 6948 frame_0_1 # Frame 19
return
sub Vanguard_part3
# Frames 20-29
2600 6019 6783 frame_0_1 # Frame 20
1500 6304 6913 frame_0_1 # Frame 21
2300 5671 6204 frame_0_1 # Frame 22
2200 4952 frame_0 # Frame 23
2600 4424 6075 frame_0_1 # Frame 24
1500 4657 frame_0 # Frame 25
1500 4308 5673 frame_0_1 # Frame 26
1500 4224 frame_0 # Frame 27
1200 6019 6594 frame_0_1 # Frame 28
2200 6326 frame_0 # Frame 29
return
sub Vanguard_part4
# Frames 30-39
1200 6400 frame_0 # Frame 30
1500 5037 frame_0 # Frame 31
2200 4435 6098 frame_0_1 # Frame 32
1500 4224 frame_0 # Frame 33
1500 6283 6547 frame_0_1 # Frame 34
2500 6030 6216 frame_0_1 # Frame 35
2500 5026 frame_0 # Frame 36
1500 4572 6346 frame_0_1 # Frame 37
2000 5702 frame_0 # Frame 38
3000 6936 frame_1 # Frame 39
return
# Restored frame_0..17_19..23
sub frame_0..17_19..23
23 servo 22 servo 21 servo 20 servo 19 servo 17 servo 16 servo 15 servo
14 servo 13 servo 12 servo 11 servo 10 servo 9 servo 8 servo 7 servo
6 servo 5 servo 4 servo 3 servo 2 servo 1 servo 0 servo
delay
return
# Other frame subroutines (unchanged)
sub frame_0_1
1 servo 0 servo
delay
return
sub frame_0
0 servo
delay
return
sub frame_1
1 servo
delay
return