How to edit code for different sized displays? e.g. 144 servos in 12 x 12 layout

[aaronse]

Hello, I am wondering how I could change the code to where it controls 144 servos with the same movements (12x12 servos). Would I only have to change the driver count and the canvas width and height on the top part of the code or do I have to modify more?

Originally posted by @SamuA00 in #3 (comment)

[aaronse]

Hello, I am wondering how I could change the code to where it controls 144 servos with the same movements (12x12 servos). Would I only have to change the driver count and the canvas width and height on the top part of the code or do I have to modify more?

Originally posted by @SamuA00 in #3 (comment)

Hello @SamuA00, yes, you're right, some constants and code will need to be edited for builds with different number of servos and/or different layouts:

• DRIVER_COUNT, should be set to number of PCA9685 drivers used. Current code assumes each driver is connected to 16 servos. So, should define as total servo count divided by 16, e.g. 9 for 144 == 12x12 servo build.
• CANVAS_WIDTH, servos per row, think of as display pixel width. So, 12 for a 12x12 build.
• CANVAS_HEIGHT, number of rows, think of as display pixel height. So, 12 for a 12x12 build.
• Adafruit_PWMServoDriver pwmDrivers[] defines a list of PCA9685 servo drivers. Each PCA9685 driver has a unique I2C address, starting at 0x40 (you solder during build assembly). The code uses this list to figure out which PCA9685 servo driver is connected to a given servo, enabling the code to send commands to a specific driver. So, for a 144 servo build, 9 entries would need to be defined, each entry with a unique I2C address based on what was soldered during WTD assembly. See lines ~260 to ~277 to understand tileset layout and wiring sequence assumed by the current code.

[SamuA00]

Thank you very much for explaining. Would the first part of the modified code look like this:

1 #include <Wire.h>
2 #include <Adafruit_PWMServoDriver.h>
3
4 // Servo driver I2C Address definitions
5 Adafruit_PWMServoDriver pwmDrivers[] =
6 {
7 Adafruit_PWMServoDriver(0x40),
8 Adafruit_PWMServoDriver(0x41),
9 Adafruit_PWMServoDriver(0x42),
10 Adafruit_PWMServoDriver(0x43),
11 Adafruit_PWMServoDriver(0x44),
12 Adafruit_PWMServoDriver(0x45),
13 Adafruit_PWMServoDriver(0x46),
14 Adafruit_PWMServoDriver(0x47),
15 Adafruit_PWMServoDriver(0x48)
16 };
17
18 #define DRIVER_COUNT 9
19
20 #define SERVOMIN 150 // This is the 'minimum' pulse length count (out of 4096)
21 #define SERVOMAX 600 // This is the 'maximum' pulse length count (out of 4096)
22 #define USMIN 600 // This is the rounded 'minimum' microsecond length based on the minimum pulse of 150
23 #define USMAX 2400 // This is the rounded 'maximum' microsecond length based on the maximum pulse of 600
24
25 #define SERVO_FREQ 60 // Analog servos run at ~60 Hz updates. Try 50 (original
26 // sample value) if your servos have a seizure using 60.
27
28 #define SERVO_COUNT 16
29
30 #define MIN_SERVO_ANGLE 0
31 #define MAX_SERVO_ANGLE 60
32 #define DEFAULT_SERVO_ANGLE 30
33
34 // Servo panel layout
35 #define TILESET_WIDTH 4
36 #define TILESET_HEIGHT 4
37 #define CANVAS_WIDTH 12
38 #define CANVAS_HEIGHT 12
39 #define PIXEL_COUNT CANVAS_WIDTH * CANVAS_HEIGHT

So do I just have to modify the first part of the code like I did above? Also I am not sure if I did lines 7 through 15 correctly.

[aaronse]

So do I just have to modify the first part of the code like I did above? Also I am not sure if I did lines 7 through 15 correctly.

You're welcome. Yep, code looks good to me. Found it helpful to methodically solder the address pins for a batch of PCA9685 servo drivers.