SC08A damage??

[zhenning]

exactly like datasheet, the different is i only use wire jumper to connect between SK40C and SC08A...in datasheet use rainbow wire right...is it affect the SC08A?

Should not affect. Anyway, the green LED is not the green LED on the SC08A right? You attached additional LED to which UART line?

[mohamad]

the green LED is in SC08A circuit, the indicator from UART connect to SK40C...the problem, first i try with only 1 servo, it's work...then, i switch off all power supply then add 2 servo, then ON the power in SK40C, it's not working anymore, i tried again with 1 servo, then also not working....

[zhenning]

the green LED is in SC08A circuit, the indicator from UART connect to SK40C...the problem, first i try with only 1 servo, it's work...then, i switch off all power supply then add 2 servo, then ON the power in SK40C, it's not working anymore, i tried again with 1 servo, then also not working....

Remove the servo just leave the SK40C and SC08A.
Check your wires. See if any wire broken. In this setup, SC08A will share 5V power source from host or microcontroller board. If
5V power source is ON and connection is correct, the small green LED (5V) will light ON to indicate controller is powered. Thus, it seems it is not getting any power from SK40C.

no, the power indicator for SC08A is ok, LED ON, but the indicator for UART (green LED, connect to SK40C) is not ON...so, i guess the problem is at UART connection..

LED on SK40C is ON...i've checked the voltage at SK40C UART, it's almost 5V...but UART at SC08A is almost zero...

Since you have mentioned you have power in SK40C, then, most likely some of your wires are broken

[mohamad]

i've checked all wire, seem not broken...and also checked the connection with multimeter, all connected...but why the power indicator on SC08A not ON? huhuhu

[robosang]

confuse, looking at the User's Manual, the Green LED indicate the logic power of SC08 which come from the UART connector. So basically, SC08 is sharing power with SK40C in your case. If the power on SC08 shorted, it should be indicated on SK40C LED too.

I am not sure why 1 servo has no problem, while 2 Servo have problem which it should not because the Servo should be taking power from Servo Power terminal. But the weird thing is the power on SK40C. Would suggest the advice by zhenning, change the wire

[mohamad]

i've change the wire, but also not working...yesterday, b4 i tried connected with 2 servo, its fine...but now, 1 servo also not working, huhuhu

[zhenning]

i've change the wire, but also not working...yesterday, b4 i tried connected with 2 servo, its fine...but now, 1 servo also not working, huhuhu

Are you sure you are connecting the right wire to the right terminal? And where do you measure at SC08A?

[hyng]

Can you please upload some photos of the connection over here so that we can identify the problem.
SC08A will not damage easily unless you had supplied more than 5V to SC08A on UART lines.
The servo power only connect to the power line of servo motors so it will not affect the MCU of SC08A.
Normally users get confused with the UART connection. The TX (SK40C) should conect to RX (SC08A) and vice versa.