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Wireless UART for debug purposes

Started by pozz November 13, 2023
I often have embedded boards with a UART that shows debug logging 
messages. Most of the times, only the TX signal is of interest, in a few 
cases the debug UART features a full command line console, so both TX 
and RX lines are of interest.

I have many UART/USB adapters and they work well when I have a desktop 
or mobile PC, running putty or Realterm or a similar software, near the 
device.

However, in some cases, the device is installed far from a PC and it's 
difficult to have USB wired cable connection. So I'm wondering if 
there's an off-the-shelf UART/wireless adapter that could help in these 
cases. Bluetooth? WiFi? Proprietary wireless protocol (with a 
priorietary dongle USB receiver)?

Do you have the same problem as me? How did you solve?
On 13/11/2023 09:10, pozz wrote:
> I often have embedded boards with a UART that shows debug logging > messages. Most of the times, only the TX signal is of interest, in a few > cases the debug UART features a full command line console, so both TX > and RX lines are of interest. > > I have many UART/USB adapters and they work well when I have a desktop > or mobile PC, running putty or Realterm or a similar software, near the > device. > > However, in some cases, the device is installed far from a PC and it's > difficult to have USB wired cable connection. So I'm wondering if > there's an off-the-shelf UART/wireless adapter that could help in these > cases. Bluetooth? WiFi? Proprietary wireless protocol (with a > priorietary dongle USB receiver)? > > Do you have the same problem as me? How did you solve?
There are plenty of Bluetooth modules with UART connections, but of course you need something at the other end. A couple of Silicon Labs evaluation boards can be configured as linked to each other - then they can act mostly like a UART cable with a wireless cable, with very little effort. If you need to have the Bluetooth module inside the device, and have one master PC talking to lots of devices, then you'll need to do a bit more work. And if it is always installed, then suddenly your device is classified as a radio communications device, with all the standards, certifications, EMC rules, and testing that goes along with that. If it is okay to plug something temporarily into the board that needs debugged, you could set up a Rasberry Pi with a USB battery pack, and plug that into your TTL-level UART debug signals on the board. Then you can have Wifi configured in any way you like. A tty to tcp/ip port converter for remote access should not be difficult to make - with Python Twisted, it's probably no more than a couple of dozen lines.
Il 13/11/2023 10:00, David Brown ha scritto:
> On 13/11/2023 09:10, pozz wrote: >> I often have embedded boards with a UART that shows debug logging >> messages. Most of the times, only the TX signal is of interest, in a >> few cases the debug UART features a full command line console, so both >> TX and RX lines are of interest. >> >> I have many UART/USB adapters and they work well when I have a desktop >> or mobile PC, running putty or Realterm or a similar software, near >> the device. >> >> However, in some cases, the device is installed far from a PC and it's >> difficult to have USB wired cable connection. So I'm wondering if >> there's an off-the-shelf UART/wireless adapter that could help in >> these cases. Bluetooth? WiFi? Proprietary wireless protocol (with a >> priorietary dongle USB receiver)? >> >> Do you have the same problem as me? How did you solve? > > There are plenty of Bluetooth modules with UART connections, but of > course you need something at the other end.  A couple of Silicon Labs > evaluation boards can be configured as linked to each other - then they > can act mostly like a UART cable with a wireless cable, with very little > effort. > > If you need to have the Bluetooth module inside the device, and have one > master PC talking to lots of devices, then you'll need to do a bit more > work.  And if it is always installed, then suddenly your device is > classified as a radio communications device, with all the standards, > certifications, EMC rules, and testing that goes along with that. > > If it is okay to plug something temporarily into the board that needs > debugged, you could set up a Rasberry Pi with a USB battery pack, and > plug that into your TTL-level UART debug signals on the board.  Then you > can have Wifi configured in any way you like.  A tty to tcp/ip port > converter for remote access should not be difficult to make - with > Python Twisted, it's probably no more than a couple of dozen lines.
I know I can design my own solution, maybe using some evaluation boards. However I was asking about something ready to use. Plug the wireless adapter on the debug UART of the device and open putty on the remote PC (here remote means reachable by the RF signal, whatever it is).
On 13/11/2023 10:39, pozz wrote:
> Il 13/11/2023 10:00, David Brown ha scritto: >> On 13/11/2023 09:10, pozz wrote: >>> I often have embedded boards with a UART that shows debug logging >>> messages. Most of the times, only the TX signal is of interest, in a >>> few cases the debug UART features a full command line console, so >>> both TX and RX lines are of interest. >>> >>> I have many UART/USB adapters and they work well when I have a >>> desktop or mobile PC, running putty or Realterm or a similar >>> software, near the device. >>> >>> However, in some cases, the device is installed far from a PC and >>> it's difficult to have USB wired cable connection. So I'm wondering >>> if there's an off-the-shelf UART/wireless adapter that could help in >>> these cases. Bluetooth? WiFi? Proprietary wireless protocol (with a >>> priorietary dongle USB receiver)? >>> >>> Do you have the same problem as me? How did you solve? >> >> There are plenty of Bluetooth modules with UART connections, but of >> course you need something at the other end.  A couple of Silicon Labs >> evaluation boards can be configured as linked to each other - then >> they can act mostly like a UART cable with a wireless cable, with very >> little effort. >> >> If you need to have the Bluetooth module inside the device, and have >> one master PC talking to lots of devices, then you'll need to do a bit >> more work.  And if it is always installed, then suddenly your device >> is classified as a radio communications device, with all the >> standards, certifications, EMC rules, and testing that goes along with >> that. >> >> If it is okay to plug something temporarily into the board that needs >> debugged, you could set up a Rasberry Pi with a USB battery pack, and >> plug that into your TTL-level UART debug signals on the board.  Then >> you can have Wifi configured in any way you like.  A tty to tcp/ip >> port converter for remote access should not be difficult to make - >> with Python Twisted, it's probably no more than a couple of dozen lines. > > I know I can design my own solution, maybe using some evaluation boards. > > However I was asking about something ready to use. Plug the wireless > adapter on the debug UART of the device and open putty on the remote PC > (here remote means reachable by the RF signal, whatever it is). > >
As I say, look at Silicon Labs Bluetooth modules. There's no point in me trying to give the details of the devices I used, since that was three or four years ago, but those were close to out-of-the-box - just configuration and setup, using the Silicon Labs mobile app. (I was communicating between two other cards, rather than a PC, but that should make little difference.) There are no doubt a dozen different vendors with similar solutions. You haven't said if you need this for two systems or two thousand systems, so that's the best answer you can get so far.
Il 13/11/2023 13:15, David Brown ha scritto:
> On 13/11/2023 10:39, pozz wrote: >> Il 13/11/2023 10:00, David Brown ha scritto: >>> On 13/11/2023 09:10, pozz wrote: >>>> I often have embedded boards with a UART that shows debug logging >>>> messages. Most of the times, only the TX signal is of interest, in a >>>> few cases the debug UART features a full command line console, so >>>> both TX and RX lines are of interest. >>>> >>>> I have many UART/USB adapters and they work well when I have a >>>> desktop or mobile PC, running putty or Realterm or a similar >>>> software, near the device. >>>> >>>> However, in some cases, the device is installed far from a PC and >>>> it's difficult to have USB wired cable connection. So I'm wondering >>>> if there's an off-the-shelf UART/wireless adapter that could help in >>>> these cases. Bluetooth? WiFi? Proprietary wireless protocol (with a >>>> priorietary dongle USB receiver)? >>>> >>>> Do you have the same problem as me? How did you solve? >>> >>> There are plenty of Bluetooth modules with UART connections, but of >>> course you need something at the other end.  A couple of Silicon Labs >>> evaluation boards can be configured as linked to each other - then >>> they can act mostly like a UART cable with a wireless cable, with >>> very little effort. >>> >>> If you need to have the Bluetooth module inside the device, and have >>> one master PC talking to lots of devices, then you'll need to do a >>> bit more work.  And if it is always installed, then suddenly your >>> device is classified as a radio communications device, with all the >>> standards, certifications, EMC rules, and testing that goes along >>> with that. >>> >>> If it is okay to plug something temporarily into the board that needs >>> debugged, you could set up a Rasberry Pi with a USB battery pack, and >>> plug that into your TTL-level UART debug signals on the board.  Then >>> you can have Wifi configured in any way you like.  A tty to tcp/ip >>> port converter for remote access should not be difficult to make - >>> with Python Twisted, it's probably no more than a couple of dozen lines. >> >> I know I can design my own solution, maybe using some evaluation boards. >> >> However I was asking about something ready to use. Plug the wireless >> adapter on the debug UART of the device and open putty on the remote >> PC (here remote means reachable by the RF signal, whatever it is). >> >> > > As I say, look at Silicon Labs Bluetooth modules.  There's no point in > me trying to give the details of the devices I used, since that was > three or four years ago, but those were close to out-of-the-box - just > configuration and setup, using the Silicon Labs mobile app.  (I was > communicating between two other cards, rather than a PC, but that should > make little difference.)  There are no doubt a dozen different vendors > with similar solutions.
I will check. In the meantime, I found many UART/WiFi adapter based on ESP-01 module. I think it should be ok.
> You haven't said if you need this for two systems or two thousand > systems, so that's the best answer you can get so far.
Less than 10 pieces should be ok :-D
On 13/11/2023 13:46, pozz wrote:
> Il 13/11/2023 13:15, David Brown ha scritto:
>> As I say, look at Silicon Labs Bluetooth modules.  There's no point in >> me trying to give the details of the devices I used, since that was >> three or four years ago, but those were close to out-of-the-box - just >> configuration and setup, using the Silicon Labs mobile app.  (I was >> communicating between two other cards, rather than a PC, but that >> should make little difference.)  There are no doubt a dozen different >> vendors with similar solutions. > > I will check. > > In the meantime, I found many UART/WiFi adapter based on ESP-01 module. > I think it should be ok. >
Yes, I would expect it to be easy to get hold of such modules and ready-made software for the ESP-32 if you prefer Wifi.
> >> You haven't said if you need this for two systems or two thousand >> systems, so that's the best answer you can get so far. > > Less than 10 pieces should be ok :-D > >
Just make sure that they are not considered part of the main system that you make, so that you don't have to test and certify them.
David Brown <david.brown@hesbynett.no> wrote:
> As I say, look at Silicon Labs Bluetooth modules. There's no point in > me trying to give the details of the devices I used, since that was > three or four years ago, but those were close to out-of-the-box - just > configuration and setup, using the Silicon Labs mobile app. (I was > communicating between two other cards, rather than a PC, but that should > make little difference.) There are no doubt a dozen different vendors > with similar solutions.
Was it this kind of thing: https://www.silabs.com/development-tools/wireless/bluetooth/bgm220-explorer-kit?tab=overview Do you just hook up TX and RX and the default firmware does the rest, or do you need to program it first?
> You haven't said if you need this for two systems or two thousand > systems, so that's the best answer you can get so far.
Seems like it's a common thing: https://www.adafruit.com/product/2479 https://www.waveshare.com/bluetooth-slave-uart-board.htm https://www.amazon.com/Bluetooth-Converter-Wireless-Transceiver-Communication/dp/B08Z3J9Y8T and I see there are some Chinese versions for about $2 + shipping: https://www.aliexpress.com/w/wholesale-bluetooth-uart.html?spm=a2g0o.home.search.0 and for wifi: https://www.aliexpress.com/w/wholesale-wifi-uart.html?spm=a2g0o.productlist.search.0 It's the kind of thing that's potentially useful to install just in case you need a recovery console on something like a router, which you can set up ahead of time so you have access without taking the thing apart when you're in a jam. Although not entirely happy with the security model of something broadcasting its pairing ability all the time when not in use. Theo
Am 13.11.2023 um 09:10 schrieb pozz:

> However, in some cases, the device is installed far from a PC and it's > difficult to have USB wired cable connection.
Define "far", and "UART" If the interface is actual RS232 of modest baudrate, it could be as simple as: make the RS232 cable long, so the USB doesn't have to be.
Hans-Bernhard Br&ouml;ker <HBBroeker@gmail.com> wrote:
>Am 13.11.2023 um 09:10 schrieb pozz:
>> However, in some cases, the device is installed far from a PC and it's >> difficult to have USB wired cable connection.
>Define "far", and "UART"
>If the interface is actual RS232 of modest baudrate, it could be as >simple as: make the RS232 cable long, so the USB doesn't have to be.
Or remote control a notebook connected to the devices UART via ssh or RDP (if you are using Windows). -- Dipl.-Inform(FH) Peter Heitzer, peter.heitzer@rz.uni-regensburg.de
Il 14/11/2023 19:47, Hans-Bernhard Br&ouml;ker ha scritto:
> Am 13.11.2023 um 09:10 schrieb pozz: > >> However, in some cases, the device is installed far from a PC and it's >> difficult to have USB wired cable connection. > > Define "far",
10-15 meters should be ok
> and "UART"
Standard TX and RX asynchronous signals as in RS232 standard, but at UART low level voltages (3.3V or 5V). Baudrates that I often use are the standard from 9600bps up to 115.2kbps.
> If the interface is actual RS232 of modest baudrate, it could be as > simple as: make the RS232 cable long, so the USB doesn't have to be.
The problem with a long cable is often the position of the device that is uncomfortable to reach. Moreover, if I want to record a long session log (for one or more days), the long cable isn't an option.