Need help with serial servo controller
reuben brewer
Posts: 2
Hi, I'm trying to use the parallax serial servo controller (http://www.parallax.com/detail.asp?product_id=28023) and am having problems. I'm using an E128 (http://www.freescale.com/files/microcontrollers/doc/data_sheet/MC9S12E128V1.pdf?fpsp=1) to generate a serial signal that goes to the servo controller. I've plugged my RS-232 output into my computer's serial jack and have confirmed that I'm sending a properly-formatted servo position command of the form
!SC channel_byte ramp_byte pwm_pos_low_byte pwm_pos_high_byte CR
@ 2400 Baud, 8 bit data, 2 stop bits.
I've connected 5v, gnd, and the serial line from my E218 to the servo controller, and I see the controller's green light blink when I send it a command. However, when I scope the channel's signal, it just stays at 1.5mS regardless of what I command it to...
Any thoughts on why this isn't working?
Much thanks!
--Reuben Brewer
rdbrewer@stanford.edu
!SC channel_byte ramp_byte pwm_pos_low_byte pwm_pos_high_byte CR
@ 2400 Baud, 8 bit data, 2 stop bits.
I've connected 5v, gnd, and the serial line from my E218 to the servo controller, and I see the controller's green light blink when I send it a command. However, when I scope the channel's signal, it just stays at 1.5mS regardless of what I command it to...
Any thoughts on why this isn't working?
Much thanks!
--Reuben Brewer
rdbrewer@stanford.edu
Comments
0x21 0x53 0x43 channel_byte ramp_byte pwm_pos_low_byte pwm_pos_high_byte 0x0D.
connection:
+5V
|
4.7Kohm resistor
|
|
serial in of PSC(white)