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Forum Index : Microcontroller and PC projects : PicoMite vs E28 module....
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Grogster Admin Group  Joined: 31/12/2012 Location: New ZealandPosts: 9610 |
Hi all.  I am planning to stop selling the E28 module at the end of the year - or when the PicoMite comes out of beta and has its first official release. The Pico module is so cheap, the E28 can't compete in terms of price OR feature-set anymore, so I am thinking it is going to be uneconomical to continue to sell it - I will just offer Pico modules pre-loaded with the latest MMBASIC firmware and an accompanying sales blurb. What does everyone else here think? The Pico module is five bucks - a very tasty price-point, especially for newbie's as it is so cheap to get started with MMBASIC using the PicoMite. The E28 module is twenty-five bucks - five times the price, and it is technically inferior to the PicoMite now in more ways then one. Thoughts and comments on this thread would help me decide weather to retire the E28 module or continue to supply it. Smoke makes things work. When the smoke gets out, it stops! |
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| Volhout Guru  Joined: 05/03/2018 Location: NetherlandsPosts: 5089 |
Hi Grogster, From a standpoint of economics the situation is clear. I think the pico sales will dominate within a year. There is (however) one essential difference between the pico and the E28. This difference is exactly the same as the difference between the Arduino UNO and the Arduino Leonardo. The UNO, and E28 both have a separate USB-serial converter. That results in continued COM connection when the CPU resets/restarts. I.e. in case of a watchdog, -or- in case of the pico: simply changing OPTION settings. This may not be of great importance while developing, Teraterm will reconnect, but in a setup where availability requirements are high and access to the application is difficult, or does not automatically reconnect, this may be important. Opposed, the pico and arduino leonardo both have embedded USB. Whenever the core CPU is reset, you loose the USB connection. Despite the fact that the Arduino Leonardo was cheaper than the Arduino UNO, the UNO (R3) is still sold. The Leonardo is already retired... I cannot help you decide, sorry... Regards, Volhout PicomiteVGA PETSCII ROBOTS |
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Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 7937 |
I'm not sure that automatic continuation of the console is all that important in the real world. It's more important that the application restarts in a safe condition - and the Pico can do that. In a lot of embedded applications (where the Pico is at its best) it's actually better if the console can't start automatically - it's a security problem. It all depends on the application. :) It also depends on what sort of demand there is for the E28 too. If there is a reasonably steady flow going out of the door I'd keep it going. If they are rarely sold then it's probably quite safe to drop them as their sale is unlikely to pick up much now. Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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CaptainBoing Guru Joined: 07/09/2016 Location: United KingdomPosts: 2170 |
a sound business decision - you have to produce what you think will sell. be mindful of customers upgrading. Their software won't go straight over coz the "special functions" are all over the place and have to be defined, there is no forward or backward direct code compatibility like there is with the other micromite platforms (hey, I tried). Edited 2021-10-01 22:27 by CaptainBoing |
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| lizby Guru Joined: 17/05/2016 Location: United StatesPosts: 3378 |
I think your analysis is correct, both regarding price and capability, and it would better serve your customers if you steered them towards the picomite. (Loved the E28 in its time, though.) PicoMite, Armmite F4, SensorKits, MMBasic Hardware, Games, etc. on fruitoftheshed |
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| robert.rozee Guru Joined: 31/12/2012 Location: New ZealandPosts: 2442 |
while the pico is quite cool, it does still have some issues that limit use. consider the following: upper=-99999999 lower=+99999999 Do Timer =0 For I=1 To 500:Print Chr$(0);: Next I elapsed=Timer Do :Loop Until Timer>upper If elapsed>upper Then upper=elapsed If elapsed<lower Then lower=elapsed If upper=lower Then I=0 Else I=71*(elapsed-lower)/(upper-lower) Print Chr$(13) Space$(78) Chr$(13) Space$(I) "*" Print Int(lower) "ms",,,, Int(elapsed) "ms",,,, Int(upper) "ms"; Loop the above measures code execution speed (not CPU clock) variations. on an MX170 the speed is pretty much rock solid, whereas the above code wanders across an approximately 4:1 range (between 55ms and 220ms) over a period of 20 seconds or so. in this case, the variation feels as if it is caused by an interaction with the pico's USB stack. in terms of stability, i'd be far more inclined to trust the MX170. where current consumption is paramount, the MX170 wins. i do feel a big plus for the pico would be if mmbasic could be configured to use a serial port for the console, instead of USB. how many (if not commercially sensitive) E-28 modules have sold, and how many over the last year? do you feel they would sell better at a lower price-point - ie, if a production run could be run through a chinese manufacturing plant? could the E-28 'live on' as a DIP-based module, scaled up to be a similar size as the pico, and sold as a blank PCB? just ideas. cheers, rob :-) Edited 2021-10-01 23:21 by robert.rozee |
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| Volhout Guru Joined: 05/03/2018 Location: NetherlandsPosts: 5089 |
You are probably not inclined to do so in this phase, but cost reduction of the E28 may be possible. Arduino sells the Arduino nano more expensive than the arduino BLE, where as the BLE has far more components and circuits. The cost difference is in the single sided component assembly (they don't have to flip the board over and do another placement run). Maybe the E28 could make use of smaller packages of the PIC32 and become single sided placement. And you could drop the pin headers (same as pico). In the end .. this would not bring the price from 25 to 5, and would require you to spin the board. I guess the pico has advantage of a/ subsidizing (Raspberry foundation wants the market, and they can only reach that when they outprice STM32 competition, i.e. the blue pill, the black pill). b/ large volume. I gues millions of these pico's have already shipped. I would not be surprised when the pi pico price is double that in a year. Look at the pi zero. General availability of that board is bad, becuase RP foundation loose money on it (-or- do not make any profit at all). Edited 2021-10-01 23:41 by Volhout PicomiteVGA PETSCII ROBOTS |
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| matherp Guru Joined: 11/12/2012 Location: United KingdomPosts: 10310 |
Rob With respect your test is pretty much meaningless. You are looking at a complex interaction of the MMBasic circular output buffer (which you are overflowing) with the USB buffering and the polling interval of the USB host. You will probably see similar things on any implementation with a USB connection. If you want to test stability replace the console I/O with uart I/O. This is always available to the user and should be used where you want determinant operation but even in that case you need to constrain the average I/O rate to be less than the baudrate. I am happy to be persuaded but I can't see any advantage of enabling the console over a serial port. The console is for development etc. where speed is not relevant. Print # etc. can do everything that Print does but of course will need additional H/W depending on the remote connection required upper=-99999999 lower=+99999999 SetPin 1,2,com1 Open "com1:230400" As #1 Do Timer =0 For I=1 To 500:Print #1,Chr$(0);: Next I elapsed=Timer Do :Loop Until Timer>upper If elapsed>upper Then upper=elapsed If elapsed<lower Then lower=elapsed Print Int(lower) "ms",,,, Int(elapsed) "ms",,,, Int(upper) "ms" Pause 100 Loop |
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| Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 7937 |
I don't know if it's true (or how it's working out), but apparently the RP2040 is aimed at at an eventual sale price point of significantly less than $1.00 US per chip in bulk. I know the investment has to be paid off, but these things must be extremely cheap to manufacture. I suspect that, if the price of the Pico goes up, then it probably won't be because of the cost of the RP2040. Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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| robert.rozee Guru Joined: 31/12/2012 Location: New ZealandPosts: 2442 |
hi peter, with respect, my test demonstrates an interesting corner case. the same behaivour is NOT observed with an E-28, which itself does use a USB interface. i would be the first to admit that what i'm doing is forcing the pico to operate in an extremely abnormal situation, but then that is what test engineering is all about. the example DOES demonstrate that the pico can be caused to behave in unexpected ways under some circumstances. the pico is hampered by the fact that firmware runs from a relatively slow external flash chip, with the processor depending upon a 16k cache to smooth things over. and in the specific case of running mmbasic there is insufficient RAM available to run anything but select portions of the firmware from RAM. if a pico processor came out with 512k (or 1mb) of RAM, then things would be really interesting! the pico, running mmbasic, is cool. it is a great platform for experimenting on, and i am sure will 'fill the bill' for many people. but it is not necessarily the solution for everyone, or for every application. there are some things it does not do well - as is the case with just about every platform out there. cheers, rob :-) |
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| Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 7937 |
Peter has a point - it's unfair to compare the result from the PicoMite (using a USB console) with the result from the E28 (using a TTL console on an-chip UART module). For a start, the USB interface will also be influenced by Windows. You can't even compare the results using the USB connection on the E28 because the USB handling isn't involved in your test (as it's on the 1455) - it's still the same UART that you use for the TTL console. To get a fair comparison you have to use a UART on the PicoMite (and possibly disable the USB). Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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| matherp Guru Joined: 11/12/2012 Location: United KingdomPosts: 10310 |
The same behaviour is not seen with PRINT #. This is the analogous comparison to the E28 using an external USB/UART. My argument is that you are exploring a case which has no real-world relevance because in a real-world example where timing is critical you wouldn't do console I/O. The PicoMite has the majority of the critical bits of MMBasic RAM resident, all main commands and the whole of the parser. You will find that run times are extremely consistent for anything other than USB console output. Of course it is not appropriate for everything but going back to Grogster's question I see the PicoMite as a replacement for the MM2 in nearly all applications and as a ready-to-go module it is cheaper, faster and easier to get running with MMBasic than the bare PIC23MX170 chip which is where the price comparison lies. My view FWIW is that the E-28 has been superseded not by the Pico but by the various Backpack modules that are available. If you look in SC every project starts with a Backpack. The PicoMite overcomes this because "backpacks" "shields" call them what you will are readily available for the Pico form factor whereas the E-28 only really comes into its own for a true "homebuilt" for the subset of users who don't want the hassle of programming the PIC and sourcing/wiring the correct VCAP, regulator, and a USB/UART module. Only Grogster can know if there are enough potential customers out there to keep supplying the E-28. It's known, available, well designed, high quality and just works so it would be a shame to see it go. |
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palcal Guru Joined: 12/10/2011 Location: AustraliaPosts: 1993 |
@ grogster I was getting boards from you and building my own E-28s but have now changed to the Picomite. I like to build my own but at the price of the Picomite it wins hands down. "It is better to be ignorant and ask a stupid question than to be plain Stupid and not ask at all" |
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phil99 Guru Joined: 11/02/2018 Location: AustraliaPosts: 2640 |
A small point in favor of the E28 is the robust source / sink of the outputs. The absolute maximum limit of the individual Pico pins isn't much less than the MX170 but the impedance is significantly higher, limiting what can be driven without buffering. The combined output current of all driven pins is also much less for the Pico, requiring more buffering. This may also be a reason the Uno and Nano are still so popular. Is 'on demand' production viable instead of keeping stock? Customers would have to wait a while so that could be an issue. |
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Geoffg Guru Joined: 06/06/2011 Location: AustraliaPosts: 3292 |
Grogster, I don't think that you will see a sudden drop in E-28 sales because of the PicoMite. The Micromite has quite a following and that will keep it going for some time. But it is mature and people tend to go for the latest and greatest, which includes the Pi Pico and the many other ARM processors. My guess is that you have already seen a steady decline in all Micromite based products and that will continue, if only because most people who want to play with one will have already bought it- but there will still be more to be sold, just a lot lower quantities. If you suddenly terminate the E-28 completely you could be doing yourself a disservice. Geoff Geoff Graham - http://geoffg.net |
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| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9610 |
Wow - a lot more replies then I was expecting!   I will continue to offer it then. I usually keep a stock of 10-15 assembled E28's on the shelf ready to sell, but those have dwindled down to zero as of last week, and the global silicon chip shortage has made getting more SOIC 170's in problematic, so I was just wondering if it would be worth the effort to keep assembled ones on the shelf etc. I also now have used up all my SOIC 170's, so I need to order more. There are a handful of SOIC chips available now, but most of the 170 parts are out of stock till September 2022!!!!  Basically, another full YEAR before some of these parts are available again, and I fully expect that to get pushed back even further if the planet does not get over this bloody virus.I like phill99's suggestion the best. I will keep it available for sale, but change the website to indicate that there will be a few days lead-time on any E28 ordered, as I will have to assemble them to order rather then keeping them on the shelf already assembled and programmed. Everyone has made very valid comments, and I thank all who took the time to post.  Technically, the E64 module is built to order now anyway, so I will just continue with that business model for the E28's moving forward. If anyone else has anything else to add, please do post it here. Smoke makes things work. When the smoke gets out, it stops! |
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