help needed with my set up

[amxen]

im running the 5v needed to power it from the usb port as every one iv talked to say that's how they run it. so im not sure if the 2 end pins need connecting as its getting its 5v from the usb. from my understanding pin14 is en- and en+ goes to 5v on the end . only from what iv seen on other videos. so this is how I have it. some one has told me I don't need to wire in the en- for now just for testing but I have tried it both ways and it still the same. To be honest im going round and round in circles with this now

[Clive S]

im running the 5v needed to power it from the usb port as every one iv talked to say that's how they run it. so im not sure if the 2 end pins need connecting as its getting its 5v from the usb. from my understanding pin14 is en- and en+ goes to 5v on the end . only from what iv seen on other videos. so this is how I have it. some one has told me I don't need to wire in the en- for now just for testing but I have tried it both ways and it still the same. To be honest im going round and round in circles with this now

You should not need anything connected to the enable pin on the bob. Can you draw a simple sketch to show exactly how you have connected the drive to the bob.. I have used many of these bobs and they work fine

[amxen]

You should not need anything connected to the enable pin on the bob. Can you draw a simple sketch to show exactly how you have connected the drive to the bob.. I have used many of these bobs and they work fine

as soon as I get home ill draw something . but im sure its correct but yes I can do that . I think I read some where that it may be that the input from the parallel port is only 3.7v dc saying it need to be 4.5v dc to activate something on the bob . Now im really clutching at straws but any hope is hope just now

[Clive S]

I think I read some where that it may be that the input from the parallel port is only 3.7v dc saying it need to be 4.5v dc to activate something on the bob .

The bob will convert the 3.7v to the required output so that will not be the problem.

[cropwell]

Have you got the 12-24v power connected ? - there is no mention of it so far ! That is needed to drive the electronics of the BoB. The 5v USB connection only powers the input opto-isolators.

[amxen]

it is my understanding that connecting the 12 24v to the bob is only to enable the use of the limit and estop on the other side of the bob.

[Clive S]

Have you got the 12-24v power connected ? - there is no mention of it so far ! That is needed to drive the electronics of the BoB. The 5v USB connection only powers the input opto-isolators.

Rob you are getting old like me It is the other way round, it needs the 12-24v for the inputs to work

[cropwell]

Rob you are getting old like me It is the other way round, it needs the 12-24v for the inputs to work

So why bother with a 5v USB connection from the PC ? Either way you need the 12-24v and the OP from his latest post indicates he has not deemed it necessary.

Somewhere in the deep brainfog of age I have a memory of a simple BOB circuit. I must look it out on t'Interweb and try and understand it better.

http://www.embeddedtronics.com (Several points of interest in this site !)

Aha! there it is - looking at the schematic pdf, now I understand the 5v from the PC is used to lift the output of the optos which feed homes, limits and Estop info back to the PC and power the input opto LEDs.