Connection to Megasquirt

OK, that might be a clue. This is not Megasquirt hardware, it is a custom controller, but it communicates with Tuner Studio and Shadow Dash in the same way that Megasquirt does. When I connect to Tuner Studio it always gives me the message that there are 17 errors and 232 warnings. I have no idea what that is all about and I can’t get rid of it, so I just ignore it and everything works just fine. I checked the connections and Tuner Studio tells me the connection type is RS232 Serial Interface, Com Port is Com5 and Baud rate is 115200. Here are the settings in my custom .ini file:

queryCommand = “Q”
signature = “MS2Extra comms342h2”
versionInfo = “S”
pageActivationDelay = 50
blockReadTimeout = 200
endianness = big
nPages = 3
pageSize = 1024, 1024, 1024
pageIdentifier = “\x01\x01”, “\x01\x02”, “\x01\x03”
burnCommand = “B%2i”, “B%2i”, “B%2i”
pageReadCommand = “C%2i%2o%2c”, “C%2i%2o%2c”, “C%2i%2o%2c”
pageValueWrite = “W%2i%2o%2c%v”, “W%2i%2o%2c%v”, “W%2i%2o%2c%v”
pageChunkWrite = “W%2i%2o%2c%v”, “W%2i%2o%2c%v”, “W%2i%2o%2c%v”
writeBlocks = on
interWriteDelay = 10

Does that help?

What ECU is this? Give me your ini file and I will take a look.

I sent you a PM and an e-mail.

What command letter does ReaDash send to get the real time variables?

RealDash implements Megasquirt serial protocol:

The data request command is read from the ini file, or ‘a’, 0, 6 as a backup default.

I was using ASCCI “O” as the OCH get command which is the MS1 command. Tuner Studio was OK with that. I changed it to ASCCI “A” in my firmware and the Tuner Studio .ini file. Tuner Studio was OK with the change but RelDash still won’t connect.
Any suggestions?

No, sorry. As you have custom ECU, we just do not have resources to help you develop it.

Well, actually, I’m not asking for any help developing my custom ECU, it’s working just fine. I’m just asking you if Real Dash can connect to it, as your web site suggests that it can connect to just about anything. If my ECU is the exception then I won’t spend any more time trying to figure out why.

I did link you the official Megasquirt serial protocol document that RealDash implements. If you follow that there should be no problems connecting to your device. Another option is to use our RealDash CAN protocol to send CAN frames over serial to connect.

I studied the Protocol and the only thing that I think I didn’t comply with was the OCH get command, which I changed, but no difference. CAN is not an option for me because I don’t know how to code it. Is RealDash expecting CAN or the “A” command?

RealDash implements the newer CRC checked protocol. You need to support at least:

0, 1, Q, X, X, X, X


0, 1, A, X, X, X, X

That looks like the command sequence if CAN Commands are enabled. In my case they are not.
When I open RealDash, with my controller running and the USB/Serial connector recognized by my PC, I get no indication from RealDash that it is trying to connect. Is that normal?

No they are not. Please read the Megasquirt serial protocol documentation to gain understading of how it works.

First command that RealDash sends is the 0, 1, Q, X, X, X, X to request version information, which must match the info in ini file. Second (0, 1, A) is the data request.

According to my latest TunerStudioAppDebug file and to the best of my knowledge Tuner Studio sends “Q” to request the version info and “A” to request the real time data. This is what my controller is expecting and it works just fine with Tuner Studio and Shadow Dash. If RealDash is sending anything else I don’t know how to modify my code for that, so it looks like RealDash will not work for me.