Tim240z Posted July 1, 2003 Share Posted July 1, 2003 OK, I have my MegaSquirt and megastim boards complete. Everything seems to be ok. Here is the problem: When I put the jumper on the #12 and #13 pins to the processor slot (w/out the processor in place) and connect to the laptop and run "HyperTerminal" to check that the signal is going round and round, it works fine. However, when I plug the processor back in, and the stimulator, the Megasquirt PC software does not see the MS ( it does not show any data in the "Runtime" screen. I have gone through several scenarios and am very frustrated now!!! Anyone have any ideas!?? Thanks, Tim Quote Link to comment Share on other sites More sharing options...
johnc Posted July 1, 2003 Share Posted July 1, 2003 You need to stimulate it faster... faster... faster... Quote Link to comment Share on other sites More sharing options...
Tim240z Posted July 1, 2003 Author Share Posted July 1, 2003 You need to stimulate it faster... faster... faster... no, no, no.....that just makes a mess Tim Quote Link to comment Share on other sites More sharing options...
Jason Jarvis Posted July 3, 2003 Share Posted July 3, 2003 It's been a while, but I seem to remember having a similar problem that turned out to be an issue with specifying the proper port in the software. I'll have to dig it out an have a look.... Quote Link to comment Share on other sites More sharing options...
jeffp Posted July 7, 2003 Share Posted July 7, 2003 Since you are using an rs232 connection, you may need to get a null modem, easy to understand explination: The RS232 port uses three wires 2,3,(7 I think) transmitt, receive and ground. If you have the transmitt and receive wires swapped you will not get any communication, but when you do the loop back like you did with the jumper it will work like it did. Make sure the ground is correct also as I have had a number of different gear not work because the ground wire was not hooked up. The ground sets the 0 volt reference for the laptop and the gear you are trying to access. Quote Link to comment Share on other sites More sharing options...
Tim240z Posted July 7, 2003 Author Share Posted July 7, 2003 Jeff, I bought a straight through serial cable and tested with an ohm meter to check ALL of the connectors on both sides of the cable. All was ok. Tim Quote Link to comment Share on other sites More sharing options...
jeffp Posted July 7, 2003 Share Posted July 7, 2003 Hi Tim, I cant remember which pin gets the ground. I am assuming you are using a DB9 connector off of your pc. But from the PC connector say pin2 is the receive, then it goes to the transmit pin on the eprom, and say pin3 on the PC is the transmit, then the eprom end of the wire goes to the receive. You need to make sure the transmit and receive lines are swapped in order for the comm to work. Transmit from the Eprom goes to the receive on the pc, and the receive on the eprom goes to the transmit on the PC. If the two wires are not swapped then you will be have the transmit line going into the transmit line on the other end. I dont have the schematic of the megasquirt so I am not sure if it is swown or not. Hope that makes it clear to you, and if you have already done this then you may have a bad setup or megasquirt. BTY what software are you using to program the megasquirt? Did they give you software to use for programing? or are you using something like procomm or procomm plus? Quote Link to comment Share on other sites More sharing options...
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