schematic for cycle satiator to PC control cable

[dewoller]

I want to make my own cycle satiator control cable.

There is reference on these forums to the need for a resistor, but I cannot find the actual circuit diagram.

I don't own any of the satiator connection wires, but I have been able to program my cycle analyst using a generic ttl-usb. Does anyone know the actual control circuit connection diagram?

Tia

Dennis

 

[amberwolf]

Since there is only one wire in and out of the Satiator for serial RX and TX, you would probably need to tie the USB-serial's TX and RX together with two resistors. Most likely a 1k to 5k ohm would work.

Connect one end of the first resistor to one end of the other one.

Connect this Y-connection point to the data line / thermal sensor line of the Satiator's output cable.

Connect the other end of the first resistor to the RX line of the USB-serial cable.

Connect the other end of the other resistor to the TX line of the USB-serial cable.

I don't remember whether Tip or Ring on the USB-serial cable is TX or RX, but in this case it doesn't matter. (Sleeve is ground)


The schematic might be in the Satiator info page on Grin Tech's site, or in it's manual, too. (haven't looked). I know the pinout for the Satiator XLR connector is there.

 

[dewoller]

Oh, thank you very much for that. That is very helpful. So both resistors are the same, between 1 and 5 k?

 

[amberwolf]

All they have to do is isolate each from the other, so you don't short out the USB-serial adapter's TX/RX electronics, so that value should be good, and they should be the same.

You can use higher resistance if you like, but at 5v, a 1kohm resistor reduces current to about 1mA, 2kohm (both in series) would be half that. I'd expect that's a safe value for most RX/TX chips in these adapters, assuming worst case of one wire being a "one" and the other a "zero" at any point. A 5kohm would make those values 5 times lower.