The Mega should be able to easily deal with 9600bps. I¹ve had it running much faster but for shorter packet lengths.
Could it be some character being sent that causes the Mega to have problem? It should not but software serial is not very robust. The loopback of the DSR/DTR as suggested would quickly eliminate that as an issue. On 28/11/17, 2:53 PM, "M100 on behalf of Ron Lauzon" <[email protected] on behalf of [email protected]> wrote: >I'm using pins 62 and 63. I am using an Arduino Mega (left over from >a previous project that needed more memory and the standard Arduino >Uno). Those are were the only available pins that would support the >RS-232 shifter. > >I'm making the assumption based on the fact that the Arduino is >faster. But it's just an assumption. But I did do a SAVE "COM:98N1E" >in my testing and more than 80 bytes were sent to the Arduino. > >For debugging right now, all characters that enter the Arduino are >echoed out the USB/Serial. So I can see everything that arrives on >the serial connection. > > >On Tue, Nov 28, 2017 at 5:46 PM, Fugu ME100 <[email protected]> wrote: >> Which pins are you using for the software serial port? It should be >>able >> to run up to at least 57600bps on the Ardruino. >> >> How do you know the 102 stops sending? Could the Arduino stop >>receiving? >> >> >> I assume at the moment you are just reading in on the Software Serial >>port >> and passing it out on the USB port to make sure everything works OK? >> >> On 28/11/17, 2:07 PM, "M100 on behalf of Ron Lauzon" >> <[email protected] on behalf of [email protected]> >>wrote: >> >>>Here's the setup I'm going to talk about: >>>Tandy 102, serial cable to my Arduino with an RS-232 shifter. I'm >>>using the SoftwareSerial library to interface the RS-232 shifter to >>>the Arduino via the Arduino's TX/RX pins - as opposed to using the USB >>>cable. >>> >>>Software-wise, this is pretty simple. I'm just writing a text file in >>>the Text app and saving it to COM:98N1E >>> >>>Here's my frustration. No matter what I do, the 102 stops sending >>>after about 80 bytes. >>> >>>The only way I could get it to work was to reduce the speed to 300 BPS >>>(and, of course, saving to COM:38N1E). >>> >>>Keep in mind that this is the 102 sending to the Arduino. I find it >>>difficult to believe that the Arduino couldn't keep up. And when I >>>tried other BPS, it stopped in exactly the same place: at 80 bytes. >>> >>>The 102 never showed an error message. Everything looked like it >>>worked fine on that end. But the rest of the text file never appeared >>>on the Arduino side. >>> >>>The Arduino set up doesn't support hardware flow control. So I >>>thought that enableing XON/XOFF would make sure that the 102 didn't do >>>that (No, I didn't see any XON/XOFF characters on the Arduino side >>>either). >>> >>> >>>Is there some sort of strangeness in the 102 that turns some sort of >>>hardware flow-control on for speeds > 300 BPS? Or did I miss setting >>>something? >>> >>>If there was a problem with one side keeping up, I expected to see >>>dropped characters, not communications just stopping after 80 bytes. >>> >>> >>>-- >>>Ron Lauzon - rlauzon at acm dot org >>> Homepage: >>>https://nam03.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwebpage >>>s. >>>charter.net%2Frlauzon%2F&data=02%7C01%7Cb4me100%40hotmail.com%7C1da1d8f1 >>>ef >>>344c75fb9108d536ac9c19%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C6364 >>>75 >>>037326050935&sdata=s6klg5s%2Bx65YTwdo%2Ba2WAWUb%2FJrU6SzRhRuIb8QbeC8%3D& >>>re >>>served=0 >>> Weblog: >>>https://nam03.safelinks.protection.outlook.com/?url=http%3A%2F%2Fronsapa >>>rt >>>ment.blogspot.com%2F&data=02%7C01%7Cb4me100%40hotmail.com%7C1da1d8f1ef34 >>>4c >>>75fb9108d536ac9c19%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C63647503 >>>73 >>>26050935&sdata=Uwa%2FOhydNv0Uof2cL%2Fpt2jMXOKEuWQwPqAf%2FQ%2FZyPYE%3D&re >>>se >>>rved=0 >>> >>>TRS-80 Pocket Computer 2 - TRS-80 Pocket Computer 4 - TRS-80 Model >>>100/102 >>>Some people like to work on old cars. But old computers are cheaper >>>and don't require a big garage. >> >> > > > >-- >Ron Lauzon - rlauzon at acm dot org > Homepage: >https://nam03.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwebpages. >charter.net%2Frlauzon%2F&data=02%7C01%7Cb4me100%40hotmail.com%7C0d46599c5d >9a47640f5908d536b2d4b4%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636475 >064052135476&sdata=rHMt0wpD0%2BBnYhyUf1d9e1nPwW87l2idMjUVk%2FwPy3o%3D&rese >rved=0 > Weblog: >https://nam03.safelinks.protection.outlook.com/?url=http%3A%2F%2Fronsapart >ment.blogspot.com%2F&data=02%7C01%7Cb4me100%40hotmail.com%7C0d46599c5d9a47 >640f5908d536b2d4b4%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C6364750640 >52135476&sdata=bpv7PU8XrmeHC44uYEJTEZqoMBkX1wXvs0B4%2BGiNVjE%3D&reserved=0 > >TRS-80 Pocket Computer 2 - TRS-80 Pocket Computer 4 - TRS-80 Model 100/102 >Some people like to work on old cars. But old computers are cheaper >and don't require a big garage.
