Serial Terminal for Pi Zero?

Hi everyone.
RISC OS has been consuming my free time recently. I recently got a Pi Zero. After giving it a workout with Raspbian I opted to move on to RISC OS. My PC runs Linux, and it feels way too clunky and overblown for the Pi with what I want to do with it. I spent way too much time fighting with it in ways I shouldn’t for an OS on a small system.
This is the first time I’ve touched RISC OS. Never had the hardware to run it before. It’s been a learning experience.

Anyway I’ve been looking high and low for a serial terminal program. All I want is a terminal that lets me talk to the UART pins. I’ve already given it the GPIO and PiSerial modules.

A terminal is pretty much step 0 for getting the hardware up and running. While I’m at it, because it may well not be the incorporated, is there an X/Y/Zmodem application floating around?
Not going to lie, sneakernet is driving me batty. It was an ordeal on it’s own to get a USB stick that worked correctly.

Currently the UART has an HC-06 Bluetooth slave module plugged into it. In Raspbian I use it to access the serial tty. In RISC OS it does nothing of course. I’d like to use the UART for initially transferring files (or SLIP/PPP if I’m feeling adventurous), and after that swap it out for an esp8266 WiFi module, which is where the serial terminal really comes in.
I need to talk to it. I don’t know where it’s head is at. Using an Arduino’s USB UART via logic level converter to funnel the data through on the PC is too unreliable to get a useful result. I’d rather just connect it to the Pi with an external 3.3v supply (grounds linked of course) so I can talk to it and get it to behave properly.

Of course I can do the last bit in Raspbian but it involves editing files before and afterward to disable and re-enable the serial tty.

If anyone can help me, please let me know. I’d even be happy with a BASIC listing if it can handle 115kbaud, and has an easy way to change baud rate.

Thanks again in advance.

Info in this thread might help:

https://www.riscosopen.org/forum/forums/12/topics/3975

Currently the UART has an HC-06 Bluetooth slave module plugged into it

If you intend to leave that connected, you could check out the recent developments on this forum for USB serial adapters, there is support for several types and a simple 115200 terminal for testing or building from the source.
Otherwise you will need a level shifter/9 pin adapter for standard hardware (only TX/RX is available) There is a USB serial adapter with four leads designed to plug in directly to the Pi, the USB plug end for a PC (and now the Iyonix thanks to Colins prolific driver).

duplicate removed

Duplicate removed, I’m wondering now if duplicates are made by multiple presses of the save key?

If you just want some program to test with I’ve modified the demonstration !SerialTerminal program that comes with my SerialUSB module to work with all serial devices – not just USB ones. If you want to change the baud rate or word format you will have to change it in the program and recompile. Just keep running the program until the serial device of your choice gets opened and then close the other windows.

If you are looking for a general terminal application, David Pilling has made Hearsay available free:
http://www.davidpilling.com/hearsay.html
The source code is also available.

I don’t know whether it does what you need or could be adapted to do so.

If you are looking for a general terminal application, David Pilling has made Hearsay available

Also !Connector updated and covered in the 2nd news story on the rool front page

Well, I feel silly. I spent ages looking for the updated version of !Connector. I’d even read that article previously yet somehow missed it.

I’ve been doing some troubleshooting. I’ve narrowed it down to something in RISC OS. Ie. I’ve probably done something wrong. There was however one point where I managed to get one directional communication between putty on the PC and !Hearsay. I could get characters typed in putty to appear in !Hearsay but not the other way round because it had that telnet address / port prompt.

!Connector sees the PiSerial driver which I have selected. I tried a simple loopback by removing the HC-06 and bridging RX and TX with a DuPont wire. The !Loop test program I found buried in PiSerial reports a Data Lost error. Trying to type characters in !Connector didn’t appear to be doing anything at first either. It appears !Connector has a window redraw issue. If I scroll the window or use another window to “paint over” it I can see the output. It appears to fill the buffer with the last character typed.

I’d really appreciate some further feedback on this.

I have a USB-Serial module. Trouble is I’ve searched everywhere and can’t find my null modem cables so I never pursued that option. I know they are somewhere…

I’m contemplating connecting my recently repaired Arduino Mega R3 workalike up to the UART via a level converter of course to use it as a smart sniffer to tell me what’s coming in and out.

Colin, I’d be interested in that program. While I’m no stranger to computers and electronics, RISC OS is new to me so I have no clue how to talk to serial devices yet.

Tristan, at present there is no support for Pi Zero in the HAL device, so the PiSerial module doesn’t know what hardware its running on.
This is because the OS_Hardware 4 call will not return a valid HAL device.
When I can finish an update to the GPIO HAL Device this will be fixed.
The latest type of Pi board covered is the MK2 B.

Thanks everybody for the information so far. I don’t have much time I can allocate to “play” so my replies are pretty slow. Sorry about that.

Tank, I appreciate your input. That really does explain a lot. My memory is pretty hazy but I recall I typed something in to the CLI that gave me feedback on the Pi model. I remember it detected some other version. Possibly it was the Mk2 B.
What has me utterly stumped is that I did manage to get communication one time from PC to !Hearsay while it had the telnet driver active. I really, really wish I knew how I pulled that one off.

Colin, incredibly stupid newbie question, but where do I put the SerialUSB module? I’m still feeling my way around. Beginner information is really hard to come by!
There’s a couple of USB-Serial TTL / 3.3v adapters with different chipsets on a slow boat from China which should arrive any month now! I’d like to be ready and see if I can get them to work when they arrive. They are slated for use on PC, Pi/Raspbian and Pi/RISC OS for various things, but I would still love access to the UART pins. The nice thing about onboard UARTs is they stay put, their throughput is usually pretty stable and they can be (ab)used for many purposes. As it is using the UART directly was the first time I’ve managed to get the esp8266 module to actually behave properly.

where do I put the SerialUSB module? I’m still feeling my way around. Beginner information is really hard to come by!

Ah right well here are your options.

1) If you just want to temporarily test it out just double click on it.

2) You can load it with your program

If your program is !MyProg (which is actually a directory – shift double click to open it), inside !MyProg you have an ‘obey’ file called !Run, the SerialUSB module and your executable program which you call !Runimage. The !Run file will look like this

wimpslot -min 300k
set MyProg$dir <obeySdir>
rmensure SerialUSB 0.07 rmload <MyProg$dir>.SerialUSB
run <MyProg$dir>.!RunImage

The first line sets the minimum amount of memory your program will run in.

The second line copies the full path of the directory containing the !run file to a system variable for you to use in you program as required to access resources in your !Myprog directory.

line 3 checks if version 0.07 or later of SerialUSB is already loaded and loads the version in your application directory if it isn’t.

The 4th line runs your program.

So when you double click on !MyProg !MyProg.!Run is run.

<obey$dir> is the full path name of the directory containing the obey file. By using this your application can be put anywhere and it will still work.

There are other ways like putting it in !boot.choices.boot.predesk and it will be loaded when you boot but loading it with your application ensures it will work for anyone if you give them your app.

Edit:

If !Runimage is something you want to run in a task window make !Run a TaskObey file instead of an Obey file

I really have to stop tiredposting. Sorry about that.
Retracing my steps I worked out what I found as a command for board identification was in Tank’s GPIO documentation.
Thanks Colin. I had worked out a fair bit but definitely not all of that, so it’s really useful. Thanks to for the clarification on where to put the module. I wasn’t sure if just putting it in predesk would cause it to be loaded at boot.
The first thing I did after getting the disk image working with the Zero (besides disabling networking) was to get AnyMode installed and get the OS set up nicely in 1200×1600 portrait, so I kind of went headlong into the FS structure.
I’ve been trying to find out the HW vectors for the UART. As far as I’m concerned PiSerial should work if it’s set up for an ‘A’ model Pi instead of the detected Mk2 B. Unfortunately I have no idea how to do that. I’m guessing it’s in Driver.s but I’m still digging in and learning about the nuts and bolts of the OS so I haven’t worked out what’s going on there yet. Besides the included docs and the forum I’m also reading Raspberry Pi RISC OS System Revealed. RISC OS is pretty different so I’m trying to get to grips with it. I keep asking myself why, then I switch to Raspbian and remember.
If I can get the UART and GPIO working enough for myself I’ll be happy. It’s forcing me to learn.

e:
Colin, I stole a little time to give SerialUSB a proper spin. I have some 3rd party Arduino workalikes with a CH340, So I chucked the demo program that echos typed characters after a newline on to one of the Megas after changing the bitrate and tried it with !SerialTerminal. It works perfectly.
Don’t remember if I said but a couple of days ago or so I altered !SerialTerminal to try to talk to PiSerial. Just the same infinite repetition of the last typed character.

As I read through the book, Tank’s asm is slowly starting to become more meaningful to me too.