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Forum Index : Microcontroller and PC projects : Multi-drop TTL
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| fred777 Regular Member  Joined: 01/07/2021 Location: United KingdomPosts: 56 |
4 picomites and a propeller2 ???? Is that a cryptominig rig ? Wow! |
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| Tinine Guru  Joined: 30/03/2016 Location: United KingdomPosts: 1646 |
 It's a machine controller that's designed to be fixable by using readily-available, socketed components. P2 handles the realtime motion-control and the PMs provide I/O expansion and also serve as user-programmable PLCs. P2 has 2-Mikroe Click sockets and three of the PMs have a Click socket each. I'm getting insane servo-PID performance from the P2; way beyond what the big guys boast about  Industry is struggling due to parts shortages. No problems here  Craig |
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| Volhout Guru Joined: 05/03/2018 Location: NetherlandsPosts: 2973 |
Are these the RP2040 femto modules ? PETSCII ROBOTS for PicoMiteVGA |
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| Tinine Guru Joined: 30/03/2016 Location: United KingdomPosts: 1646 |
Pimoroni PGA2040 All pins available |
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| fred777 Regular Member Joined: 01/07/2021 Location: United KingdomPosts: 56 |
How are you handling the communications on the picomite side? Do you use pio? I’d really appreciate some insights as I need to replace a number of picaxe+propeller1 based setups soon. |
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| Tinine Guru Joined: 30/03/2016 Location: United KingdomPosts: 1646 |
Nothing special, just PMBasic. Looks for a header (&HAA in my case) and then the assigned address. If the address matches then my "command", "control" and "data-bytes" are decoded if the checksum is good. Each RP2040 (because this is not a PicoMite) has 12 DI and 12 DO. When the Prop requests the state of the DI, a 3-byte + csum binary packet is formed and sent. This is nominally the low-priority I/O but even @57.6K Baud, the turnaround is < 1.5mS for all 12-bits. I have a Prop2-cog dedicated to this scanning and it stores the values in global variables for use by other cogs. Soooo nice to not have "performance anxiety" I love the pulsed-output feature of PMBasic and so all the Prop needs to do is nominate the DO and the delay value. It's also nice to have all these independent watchdogs Craig |
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| fred777 Regular Member Joined: 01/07/2021 Location: United KingdomPosts: 56 |
Great stuff! Using the RP2040 as an I/O expander, I like it and the they still are dead cheap |
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| Tinine Guru Joined: 30/03/2016 Location: United KingdomPosts: 1646 |
And available Parallax show 12,500 P2s Yup, I'm ready to dominate the controls industry Sheep can keep on waiting for their ARM processors. I had a client go with the high end Omron motion controller....minimum 22 week delivery so now he's coming to me Craig |
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| JohnS Guru Joined: 18/11/2011 Location: United KingdomPosts: 3525 |
The Pico is ARM, isn't it? John |
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| Tinine Guru Joined: 30/03/2016 Location: United KingdomPosts: 1646 |
Sure, that "charity" has no problem with sourcing but everyone else is screwed. If the 2040 became short, I'd go 100% Prop and have to live without a BASIC interpreter. One of the guys on the Parallax forum got all excited when I mentioned the "open source" Picomite. Says the licence is still restrictive. Dunno. Craig |
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CaptainBoing Guru Joined: 07/09/2016 Location: United KingdomPosts: 1979 |
depends on your PoV https://geoffg.net/OpenSource.html |
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Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 5039 |
It's hardly restrictive. It just wants the licensee to be honest and not attempt to steal the software. Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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| Tinine Guru Joined: 30/03/2016 Location: United KingdomPosts: 1646 |
Hey Cap'n Yeah I understand that some knobhead took MMBasic for his own and that ain't cool. Everything at Parallax is open source, including the P1 chip itself so they see conditions as restrictions. Man, just imagine a core interpreter controlling seven other processors that can handle a mix of Basic/C/Spin/PASM. I personally don't care as long as some form of MMBasic device is readily available as a front end to the Propeller. |
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Grogster Admin Group  Joined: 31/12/2012 Location: New ZealandPosts: 8852 |
...and that is why those that don't like the MMBASIC license, don't like the MMBASIC license. Anyone who complains about the MMBASIC license, has other agendas IMHO. Give credit to Geoff Graham and Peter Mather, and you can use MMBASIC for anything you like. And the code is free! How is that restrictive?!(rhetorical) Sigh.... But I digress, and I suppose it is best not to go down that open-source/closed-source spider burrow again - you tend to get eaten.  Smoke makes things work. When the smoke gets out, it stops! |
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