 Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me. |
Forum Index : Microcontroller and PC projects : CMM2 COM3 Connections
| Author | Message | ||||
Chopperp Guru  Joined: 03/01/2018 Location: AustraliaPosts: 1097 |
Hi Just wondering: If you disable the serial console, how do you actually physically connect the new serial I/O to the CMM2 (as COM3)? Do you use the 2 USB data lines on Con1 or do you remove IC1 & connect to socket pins 5 & 6 or do something else? Brian ChopperP |
||||
| matherp Guru Joined: 11/12/2012 Location: United KingdomPosts: 10310 |
You either use USB or to use TTL then remove IC1 Edited 2020-07-10 22:58 by matherp |
||||
| Chopperp Guru Joined: 03/01/2018 Location: AustraliaPosts: 1097 |
So do you just use a USB to TTL converter connected to the USB socket? Edited 2020-07-10 23:04 by Chopperp ChopperP |
||||
Sasquatch Guru Joined: 08/05/2020 Location: United StatesPosts: 377 |
IC1 IS a USB to TTL converter. If you need a USB connection on COM3: you can just plug a cable into the "B" socket just as you would for the console. If you need TTL serial on COM3: (for example a GPS) you should probably remove IC1 and then you can connect directly. Keep in mind the TTL level signals are actually 3.3V and not 5V. -Carl |
||||
| Chopperp Guru Joined: 03/01/2018 Location: AustraliaPosts: 1097 |
Hi Sasquatch. I did sort of realise that IC1 is a TTL USB converter but maybe with it disabled, the data pins could be directly used for TTL. I was also just wondering if it would support one going the other way, save removing IC1. You would still need to supply power to the unit through the connector. Brian. Edited 2020-07-10 23:50 by Chopperp ChopperP |
||||
vegipete Guru Joined: 29/01/2013 Location: CanadaPosts: 1132 |
I would think that disabling the serial console only changes the way the firmware interprets data coming/going on com3. The hardware itself is unchanged. Visit Vegipete's *Mite Library for cool programs. |
||||
| Chopperp Guru Joined: 03/01/2018 Location: AustraliaPosts: 1097 |
Yes, I thinking about it, I would say that would be the case. ChopperP |
||||
KeepIS Guru Joined: 13/10/2014 Location: AustraliaPosts: 1882 |
I have removed the IC on mine and fitted the ISCP header pins. By placing two links into the IC socket, assuming you have a socket, I can use the ISCP header to plug in or switch between a WIFI link or serial link (using a cp20xxx TTL to USB convertor), and obviously use the physical port connector as 5v in. No change to the board and no wires soldered. Mike. NANO Inverter: Full download - Only Hex Ver 8.1Ks |
||||
| Chopperp Guru Joined: 03/01/2018 Location: AustraliaPosts: 1097 |
@ keepIS. Sounds like a good way to go. Thanks for that. I was considering making an adaptor board to plug into the IC socket, & wiring in another IC socket but having the data pins going to a switch so the Waveshare board can be switched between IC1 or an external serial input. Might be a bit cramped for room to do that. Brian ChopperP |
||||
| KeepIS Guru Joined: 13/10/2014 Location: AustraliaPosts: 1882 |
Hi Brian, that was my initial idea but I didn't have a suitable plug. Then I realised the header has 3v, GND, TTL IO by using two links in the socket and is easier to plug into. I run everything here at 240300 baud and there is a note from Microchip admitting that there is a problem with the MCP2221A at that speed, and the stupid Windows .NET framework is COM interface is a crap shoot when working with the device Driver for these, or it's own generic driver. So I use a CP201X device or the ESP8266 when talking to my Setup / test application. Mike. NANO Inverter: Full download - Only Hex Ver 8.1Ks |
||||
 Print this page |
 |
The Back Shed's forum code is written, and hosted, in Australia. | © JAQ Software 2025 |
