Use on RPi 2 with GPIO Serial and a 96 MHz Propeller 1.

[BrianHoldsworth]

I'm trying to use proploader on a Raspberry Pi 2 with a Propeller HAT. The HAT has a 6 MHz crystal, and was originally created 5 or 6 years ago. The documentation for the HAT refers to propman, rather than this project.

I haven't tried using propman. With proploader I am doing a command like this:

$ proploader -D clkfreq=96000000 -s blink.binary -v

This doesn't work and I always get: "ERROR: Propeller not found on /dev/ttyAMA0".

I have disabled the serial console on my Pi. And there doesn't seem to be any conflict with accessing the serial device on the Pi side.

Is it possible that proploader is incompatible with the Propeller HAT, even though documentation indicates it worked fine with propman?

[PropGit]

proploader communicates via serial port or WiFi, but it sounds like you have a direct connection via RPi I/O pin.

I wasn't aware that propman had this feature, but you can find the propman (Propeller Manager) repository here: https://github.com/parallaxinc/PropellerManager

[BrianHoldsworth]

@PropGit Well, yes and no. The Propeller HAT uses the UART on the RPI's GPIO header. So it is just a serial port connected to the appropriate pins on the Propeller 1, much as you would do from any PC connecting to the Propeller.

I may need to install Raspbian (currently using Arch), and the PropellerIDE, and try with propman. If I can get that working, it would seem easier to speculate on what could prevent it from working with proploader, right?

[PropGit]

I see. Perhaps it's using the RTS signal rather than the DTR signal to reset the Propeller. Do you have an oscilloscope that you could use to monitor the Propeller's reset pin during download from PropLoader?

[BrianHoldsworth]

I think that could be the problem. The Propeller HAT schematic shows that GPIO 17 on the Pi is connected to the Propeller RESET. I think that GPIO 17 has the alternate function of being an RTS signal for the UART.

Is this a known difference between proploader and propman?

[drawkula]

p1load might help:
https://github.com/dbetz/p1load/blob/master/osint_linux.c#L57-L60

[BrianHoldsworth]

@drawkula Indeed. I compiled p1load and it works fine. So is there an actual issue with proploader not being "RPi GPIO UART compatible"?

I'm assuming that proploader would work on my RPi 2 if I was routing through a USB-Serial adapter from the Pi to the Propeller, instead of just plugging onto the GPIO header. Maybe that is too rare of a use-case to warrant support in proploader.

[drawkula]

Propeller loaders using USB ™should™ work on the PI+Linux like on every other Linux system.

[PropGit]

Proploader seems to have support for this. The help says to use the -D option to set the reset variable. I can't find documentation on exactly what, but looks like '-D reset=rts' based on code I see in the repo.

There's also direct mention (and configuration?) for RPi listed in the top entry in code I found with this search: https://github.com/parallaxinc/PropLoader/search?q=reset&unscoped_q=reset

[BrianHoldsworth]

@PropGit I tried proploader -D reset=rts ... but getting the same error.

Looking at the code linked above from p1load, it is actually handling three cases: DTR, RTS, and GPIO 17 on the RPi. So, perhaps my setup isn't even enabling any flow-control and just relies on code directly controlling GPIO 17 at the appropriate time(s).

[dbetz]

I have a propeller hat somewhere. I’ll find it and give it a try.

…

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On Aug 13, 2020, at 4:04 PM, Brian Holdsworth ***@***.***> wrote:  I think that could be the problem. The Propeller HAT schematic shows that GPIO 17 on the Pi is connected to the Propeller RESET. I think that GPIO 17 has the alternate function of being an RTS signal for the UART. Is this a known difference between proploader and propman? — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub, or unsubscribe.

[dbetz]

Which model of RaspberryPi are you using? I found my Propeller Hat but it was plugged into an ancient Raspberry Pi 1 Model A+. I think the serial ports have changed in the more recent models. Which are you using?

[BrianHoldsworth]

@dbetz I'm using the RPi 2 Model B, which has the standard 40-pin GPIO connector used on all RPi's except the original, which had the 26-pin GPIO connector. Your A+ has the same connector. The RPi 3 changes which serial port peripheral on the SoC is connected to the GPIO (/dev/ttyS0 instead of /dev/ttyAMA0).

[dbetz]

I gave up on the Model A board and switched to a RPi 3 Model B. I have proploader built for the Pi. What command line did you use and what file are you trying to load? Any chance you could send it to me?

[BrianHoldsworth]

@dbetz Command-line is as described in my first post above. File I'm trying to load is the blink.binary file that I compiled using openspin on the Pi, from the blink.spin file included in the repo.

https://github.com/parallaxinc/PropLoader/blob/master/blink.spin

[dbetz]

Okay, thanks. That's what I'm doing as well. I'll work on this more tonight. I have everything built and installed so I hope it won't be difficult to get this bug fixed. Thanks for reporting it!