BasicMicro - Forums

I've searched, but not found, anything specific to this. So, forgive me if it has already been covered.

It seems to me that what's being called a "timeout" with HSERIN is actually a delay before a jump to the "timeout label" regardless of the state of the receive buffer. If the buffer is empty, it looks like a timeout, but if the data is there, it gets it, waits the specified period, then jumps to the specified label.

In other words,

...

HSERSTAT 0
Main
...
GOSUB GetGPS
...
END

GetGPS
HSERSTAT 4, GetGPS
HSERIN NoData, 1000, [WAIT("@"),STR GPSStr5413]
...
HSERSTAT 0
Return

NoData
...
GOTO Main

always results in a jump to "NoData" after 1 second even though the string was retreived and assigned to "GPSStr".

Can anyone confirm this or show me where I'm going wrong?

Thanks,
Don

Well, for one thing, you're "got good data" is a "Return", while your "timeout" is a "GOTO". This will over-run the subroutine return stack very quickly.

Also, you have a 'WAIT' parameter, as well as "looking for character 13" parameter, as well as "54 characters" clause. I wasn't aware that HSERIN supported all those parameters.

Oops. That was a typo. I didn't really do that in the code.

Well, the book says that HSERIN is similar to SERIN and refers the reader to the SERIN section for more information. It doesn't give much (any?) meaningful info under HSERIN, like no mention of the timeout. I can't say with certainty, but I'm pretty sure that the "WAIT", "# of characters", and "13" parameters work. Certainly, they don't generate any compiler errors.

Seems like there is a lot of confusion about HSERIN on this forum. I was hoping someone from tech support could step in and give an accurate discription of its operation.

I had a brainstorm and downloaded the MBasic manual. Here's what it says:

HSERIN..HSEROUT
SETHSERIAL mode
HSERIN {label,timeout,}[InputData]
HSEROUT [InputData]

Receive and Send Asynchronous RS-232 data.

label,Timeout(optional) is a label that will be jumped to if the hserin
buffer has no data available in the buffer and the timeout period has
expired. If a timeout is not defined the hserin command will wait
indefinitely while the uart receive buffer is empty.

InputData can be a list of variables and or modifiers that tell
HSERIN / HSEROUT what to do when sending or receiving data.

All the modifiers supported by SERIN and SEROUT are supported
by HSERIN and HSEROUT.


Is it safe to assume that this also applies to the Atom?

Yup, it's safe to assume that.

Which still leaves the issue -- why is it timing out every time?

I'm betting it wants the CHR(13), and it's not getting it.

I bet you're right! That's easy enough to test. I'll let you know.

No, it isn't the CHR(13) after all. I took it out and it's still the same. I even took out the "wait", to no avail. The thing is, I can live with it. In fact, it's a nice way to generate a delay.

You misunderstand -- if you took the "13" off, it would wait for 54 characters, and timeout. If you're not even SENDING a "CR" from VB (or whatever), THEN the "13" clause won't activate, and it will timeout.