Topics

V5.1 and Nextion 5”

Murray Wills (ZL2IQ)
 

Hi. I am having trouble with the above combination and the Tft file for the enhanced nextion 5” screen. It seems it may be sized for the wrong size screen as it only takes up about a third of the screen and flashes on and off. 

Anyone else had this problem? 

Cheers
Murray ZL2IQ

Sam Tedesco
 

go to files on the left column of this site. Search 5" Nextion. You'll see a selection for your enhanced screen. Joe and another (sorry...forgot his name) built a beautiful tft.

Mark Hatch
 

Look in the files section under AJ6CU.  You will find an enhanced, enhanced 5" screen. :-)

73
Mark

Murray Wills (ZL2IQ)
 

Thank you very much. I will do that Mark.

73 Murray ZL2IQ




On Mon, Aug 5, 2019 at 1:09 PM +1200, "Mark Hatch" <mark2382@...> wrote:

Look in the files section under AJ6CU.  You will find an enhanced, enhanced 5" screen. :-)

73
Mark

Murray Wills (ZL2IQ)
 

Thanks Sam.




On Mon, Aug 5, 2019 at 12:35 PM +1200, "Sam Tedesco" <stedesco619@...> wrote:

go to files on the left column of this site. Search 5" Nextion. You'll see a selection for your enhanced screen. Joe and another (sorry...forgot his name) built a beautiful tft.

Mike Woods
 

Murray

The screen flashing on and off is a pretty good sign of your power supply being overloaded.  That 5" screen draws quite a bit of current and if you are powering off the Raduino it will not supply sufficient current to the Raduino and the 5" Nextion.

73 Mike ZL1AXG ubitx.net


On 5/08/19 7:19 PM, Murray Wills wrote:
Thanks Sam.




On Mon, Aug 5, 2019 at 12:35 PM +1200, "Sam Tedesco" <stedesco619@...> wrote:

go to files on the left column of this site. Search 5" Nextion. You'll see a selection for your enhanced screen. Joe and another (sorry...forgot his name) built a beautiful tft.


--
Mike Woods
mhwoods@...

Murray Wills (ZL2IQ)
 

Ah ok. I am powering the uBITx off a 40amp PSU at 13.8 v. As I am writing that I think you are saying that I should power just the screen off a separate 5v power supply?

Cheers Mike
Murray




On Mon, Aug 5, 2019 at 8:23 PM +1200, "Mike Woods" <mhwoods@...> wrote:

Murray

The screen flashing on and off is a pretty good sign of your power supply being overloaded.  That 5" screen draws quite a bit of current and if you are powering off the Raduino it will not supply sufficient current to the Raduino and the 5" Nextion.

73 Mike ZL1AXG ubitx.net


On 5/08/19 7:19 PM, Murray Wills wrote:
Thanks Sam.




On Mon, Aug 5, 2019 at 12:35 PM +1200, "Sam Tedesco" <stedesco619@...> wrote:

go to files on the left column of this site. Search 5" Nextion. You'll see a selection for your enhanced screen. Joe and another (sorry...forgot his name) built a beautiful tft.


--
Mike Woods
mhwoods@...

Herman Scheper
 

Hello Murray,

 

I also have the 5”Nextion enhanced and use a step down convertor for  13V-5V /1.5A ( 22 x 18 mm ) here about1.5 $.

No problems at all. The 5 V stabiliser on the Arduino has to low capacity to feed de big Arduino!

 

Success!

 

Van: BITX20@groups.io <BITX20@groups.io> Namens Murray Wills (ZL2IQ)
Verzonden: maandag 5 augustus 2019 10:32
Aan: bitx20@groups.io; bitx20@groups.io
Onderwerp: Re: [BITX20] V5.1 and Nextion 5”

 

Ah ok. I am powering the uBITx off a 40amp PSU at 13.8 v. As I am writing that I think you are saying that I should power just the screen off a separate 5v power supply?

 

Cheers Mike

Murray

 



On Mon, Aug 5, 2019 at 8:23 PM +1200, "Mike Woods" <mhwoods@...> wrote:

Murray

 

The screen flashing on and off is a pretty good sign of your power supply being overloaded.  That 5" screen draws quite a bit of current and if you are powering off the Raduino it will not supply sufficient current to the Raduino and the 5" Nextion.


73 Mike ZL1AXG ubitx.net

 

 

On 5/08/19 7:19 PM, Murray Wills wrote:

Thanks Sam.

 



On Mon, Aug 5, 2019 at 12:35 PM +1200, "Sam Tedesco" <stedesco619@...> wrote:

go to files on the left column of this site. Search 5" Nextion. You'll see a selection for your enhanced screen. Joe and another (sorry...forgot his name) built a beautiful tft.

 

--
Mike Woods
mhwoods@...

Evan Hand
 

Murray,

What Mike is saying is that the 5" screen may be too much for the 7805 5 volt regulator in the Raduino that comes with the uBitx.  There are a number of options, everything from modifying the Raduino regulator circuit, to simply adding another 7805 5 volt dc regulator. 

Background:
The 13.8 volt power supply is much more than the uBitx needs.  The 13.8 volts is good for the finals, however the rest of the board prefers the specified 12 volts.  That is why there are two power connections on the uBitx board.  The 7805 5 volt regulator on the Raduino runs off of the uBitx board supply, not the finals supply.  As currently connected it needs to drop that 13.8 volts to 5 volts.  The difference is dissipated as heat by the regulator.  The amount of heat  depends on the current draw through it. The recommended power supply for the display by Nextion is 5 volts at 1 amp.  Much more than the stock Raduino setup can provide.  

Here is the Nextion spec sheet:
https://nextion.itead.cc/datasheets/nx8048k050/ 

Suggestion:
Based on the current requirements I would suggest that you add another, separate 5 volt power for the Nextion display. This can be based on a 7806 type of regulator like one that is in the Raduino, however it will need a dropping resistor, heat sink, and the appropriate filter capacitors to work.  Another option is to by an assembled 12 volt to 5 volt reducer.  The watch out here is that it could generate noise as most are pulsed based circuits.

Here is an example datasheet for the 7805.
  https://www.sparkfun.com/datasheets/Components/LM7805.pdf

See figure 1 on page 7.  It gives typical input and output capacitor values, though does not cover a dropping resistor. 

Since the input is relatively high compared to the minimum required, and the power dissipation is dependent on the voltage drop times the current (nominal 13.8 - 5 = 8.8 volts times the max current of 1 amp = 8.8 watts).  Much higher than the design dissipation even with a heat sink.  Adding a voltage dropping resistor to get the dissipation lower is suggested.  The minimum specified input voltage is 7 volts.  I would use 8 volts to account for any variations in the input supply.  That means we need to drop the 13.8 volts to 8 volts with a resistor at the current draw of the specified 1 amp.  For this I would use a 4 or 5 ohm power resistor rated for 4 or 5 watts respectively.  Since this is the DC part of the radio, wire wound works well. The actual value of resistor would be 5.8 ohms and 6 watts.  You can go lower in value, just means more heat to be dissipated by the regulator, but do not go higher as at some point the input voltage may drop below minimum.

You will need to add a heat sink on the regulator.  This can be the case if it is aluminum, and you install the appropriate insulators for the mounting.  I would go with a separate heat sink similar to the one on the finals.

Another suggestion is to put a voltage drop between the 13.8 volt supply and the uBitx board.  This involves separating the red and brown power supply wires (per the supplied connector).   To that end I would recommend adding 2 4n4000 series diodes to drop the 13.8 volts to 12 volts to the RED wire.  4n4000 series diodes are rated for only 1 amp, so you will need to separate the finals supply and connect it directly to the 13.8 volt source.  If you do this modification as well, will need to go back and recalculate the voltage and resistor values for the Nextion display above.  I am using a 4 ohm 4 watt resistor in my setup, with the diodes to drop the voltage to the main uBitx board.

Please take the above with a grain of salt.  There may be errors, so verify.

Good luck with the build.

73
Evan
AC9TU

Mark Hatch
 

Murray,

I found a 7805 with a higher rating on Amazon (maybe 1.5A?). Mounted it on a heat sink attached to the rear panel (using it now as a large heat sink) on a small perf board (with appropriate capacitors) and then brought in a set of 5V wires to replace the 7805 on the one on the Rad. No problems so far. But will watch it. If it fails, I will follow Evan's advice and add the diodes/resistors.

73
Mark

Murray Wills (ZL2IQ)
 

Thank you Herman I will do that also.
73 Murray




On Mon, Aug 5, 2019 at 11:04 PM +1200, "Herman Scheper" <Hsrscheper@...> wrote:

Hello Murray,

 

I also have the 5”Nextion enhanced and use a step down convertor for  13V-5V /1.5A ( 22 x 18 mm ) here about1.5 $.

No problems at all. The 5 V stabiliser on the Arduino has to low capacity to feed de big Arduino!

 

Success!

 

Van: BITX20@groups.io <BITX20@groups.io> Namens Murray Wills (ZL2IQ)
Verzonden: maandag 5 augustus 2019 10:32
Aan: bitx20@groups.io; bitx20@groups.io
Onderwerp: Re: [BITX20] V5.1 and Nextion 5”

 

Ah ok. I am powering the uBITx off a 40amp PSU at 13.8 v. As I am writing that I think you are saying that I should power just the screen off a separate 5v power supply?

 

Cheers Mike

Murray

 



On Mon, Aug 5, 2019 at 8:23 PM +1200, "Mike Woods" <mhwoods@...> wrote:

Murray

 

The screen flashing on and off is a pretty good sign of your power supply being overloaded.  That 5" screen draws quite a bit of current and if you are powering off the Raduino it will not supply sufficient current to the Raduino and the 5" Nextion.


73 Mike ZL1AXG ubitx.net

 

 

On 5/08/19 7:19 PM, Murray Wills wrote:

Thanks Sam.

 



On Mon, Aug 5, 2019 at 12:35 PM +1200, "Sam Tedesco" <stedesco619@...> wrote:

go to files on the left column of this site. Search 5" Nextion. You'll see a selection for your enhanced screen. Joe and another (sorry...forgot his name) built a beautiful tft.

 

--
Mike Woods
mhwoods@...

Evan Hand
 

I tried the Buck Boost converters and found interference on the upper bands of the ubitx.  There are enough birdies that I tried to stay away from adding any more.

My opinion / observations.  yours may be different.

73
Evan
AC9TU

Murray Wills (ZL2IQ)
 

Thank you Evan for the time you have taken to help me out.

73 Murray ZL2IQ

 

From: BITX20@groups.io <BITX20@groups.io> On Behalf Of Evan Hand
Sent: Monday, 5 August 2019 11:11 PM
To: BITX20@groups.io
Subject: Re: [BITX20] V5.1 and Nextion 5”

 

Murray,

What Mike is saying is that the 5" screen may be too much for the 7805 5 volt regulator in the Raduino that comes with the uBitx.  There are a number of options, everything from modifying the Raduino regulator circuit, to simply adding another 7805 5 volt dc regulator. 

Background:
The 13.8 volt power supply is much more than the uBitx needs.  The 13.8 volts is good for the finals, however the rest of the board prefers the specified 12 volts.  That is why there are two power connections on the uBitx board.  The 7805 5 volt regulator on the Raduino runs off of the uBitx board supply, not the finals supply.  As currently connected it needs to drop that 13.8 volts to 5 volts.  The difference is dissipated as heat by the regulator.  The amount of heat  depends on the current draw through it. The recommended power supply for the display by Nextion is 5 volts at 1 amp.  Much more than the stock Raduino setup can provide.  

Here is the Nextion spec sheet:
https://nextion.itead.cc/datasheets/nx8048k050/ 

Suggestion:
Based on the current requirements I would suggest that you add another, separate 5 volt power for the Nextion display. This can be based on a 7806 type of regulator like one that is in the Raduino, however it will need a dropping resistor, heat sink, and the appropriate filter capacitors to work.  Another option is to by an assembled 12 volt to 5 volt reducer.  The watch out here is that it could generate noise as most are pulsed based circuits.

Here is an example datasheet for the 7805.
  https://www.sparkfun.com/datasheets/Components/LM7805.pdf

See figure 1 on page 7.  It gives typical input and output capacitor values, though does not cover a dropping resistor. 

Since the input is relatively high compared to the minimum required, and the power dissipation is dependent on the voltage drop times the current (nominal 13.8 - 5 = 8.8 volts times the max current of 1 amp = 8.8 watts).  Much higher than the design dissipation even with a heat sink.  Adding a voltage dropping resistor to get the dissipation lower is suggested.  The minimum specified input voltage is 7 volts.  I would use 8 volts to account for any variations in the input supply.  That means we need to drop the 13.8 volts to 8 volts with a resistor at the current draw of the specified 1 amp.  For this I would use a 4 or 5 ohm power resistor rated for 4 or 5 watts respectively.  Since this is the DC part of the radio, wire wound works well. The actual value of resistor would be 5.8 ohms and 6 watts.  You can go lower in value, just means more heat to be dissipated by the regulator, but do not go higher as at some point the input voltage may drop below minimum.

You will need to add a heat sink on the regulator.  This can be the case if it is aluminum, and you install the appropriate insulators for the mounting.  I would go with a separate heat sink similar to the one on the finals.

Another suggestion is to put a voltage drop between the 13.8 volt supply and the uBitx board.  This involves separating the red and brown power supply wires (per the supplied connector).   To that end I would recommend adding 2 4n4000 series diodes to drop the 13.8 volts to 12 volts to the RED wire.  4n4000 series diodes are rated for only 1 amp, so you will need to separate the finals supply and connect it directly to the 13.8 volt source.  If you do this modification as well, will need to go back and recalculate the voltage and resistor values for the Nextion display above.  I am using a 4 ohm 4 watt resistor in my setup, with the diodes to drop the voltage to the main uBitx board.

Please take the above with a grain of salt.  There may be errors, so verify.

Good luck with the build.

73
Evan
AC9TU

 

I used a 4.3-inch Nextion screen with no problems.

David Posthuma
WD8PUO

 


From: bitx20@groups.io on behalf of Murray Wills (ZL2IQ) <murray@...>
Sent: Monday, August 5, 2019 6:27 PM
To: bitx20@groups.io
Subject: Re: [BITX20] V5.1 and Nextion 5”
 

Thank you Evan for the time you have taken to help me out.

73 Murray ZL2IQ

 

From: BITX20@groups.io <BITX20@groups.io> On Behalf Of Evan Hand
Sent: Monday, 5 August 2019 11:11 PM
To: BITX20@groups.io
Subject: Re: [BITX20] V5.1 and Nextion 5”

 

Murray,

What Mike is saying is that the 5" screen may be too much for the 7805 5 volt regulator in the Raduino that comes with the uBitx.  There are a number of options, everything from modifying the Raduino regulator circuit, to simply adding another 7805 5 volt dc regulator. 

Background:
The 13.8 volt power supply is much more than the uBitx needs.  The 13.8 volts is good for the finals, however the rest of the board prefers the specified 12 volts.  That is why there are two power connections on the uBitx board.  The 7805 5 volt regulator on the Raduino runs off of the uBitx board supply, not the finals supply.  As currently connected it needs to drop that 13.8 volts to 5 volts.  The difference is dissipated as heat by the regulator.  The amount of heat  depends on the current draw through it. The recommended power supply for the display by Nextion is 5 volts at 1 amp.  Much more than the stock Raduino setup can provide.  

Here is the Nextion spec sheet:
https://nextion.itead.cc/datasheets/nx8048k050/ 

Suggestion:
Based on the current requirements I would suggest that you add another, separate 5 volt power for the Nextion display. This can be based on a 7806 type of regulator like one that is in the Raduino, however it will need a dropping resistor, heat sink, and the appropriate filter capacitors to work.  Another option is to by an assembled 12 volt to 5 volt reducer.  The watch out here is that it could generate noise as most are pulsed based circuits.

Here is an example datasheet for the 7805.
  https://www.sparkfun.com/datasheets/Components/LM7805.pdf

See figure 1 on page 7.  It gives typical input and output capacitor values, though does not cover a dropping resistor. 

Since the input is relatively high compared to the minimum required, and the power dissipation is dependent on the voltage drop times the current (nominal 13.8 - 5 = 8.8 volts times the max current of 1 amp = 8.8 watts).  Much higher than the design dissipation even with a heat sink.  Adding a voltage dropping resistor to get the dissipation lower is suggested.  The minimum specified input voltage is 7 volts.  I would use 8 volts to account for any variations in the input supply.  That means we need to drop the 13.8 volts to 8 volts with a resistor at the current draw of the specified 1 amp.  For this I would use a 4 or 5 ohm power resistor rated for 4 or 5 watts respectively.  Since this is the DC part of the radio, wire wound works well. The actual value of resistor would be 5.8 ohms and 6 watts.  You can go lower in value, just means more heat to be dissipated by the regulator, but do not go higher as at some point the input voltage may drop below minimum.

You will need to add a heat sink on the regulator.  This can be the case if it is aluminum, and you install the appropriate insulators for the mounting.  I would go with a separate heat sink similar to the one on the finals.

Another suggestion is to put a voltage drop between the 13.8 volt supply and the uBitx board.  This involves separating the red and brown power supply wires (per the supplied connector).   To that end I would recommend adding 2 4n4000 series diodes to drop the 13.8 volts to 12 volts to the RED wire.  4n4000 series diodes are rated for only 1 amp, so you will need to separate the finals supply and connect it directly to the 13.8 volt source.  If you do this modification as well, will need to go back and recalculate the voltage and resistor values for the Nextion display above.  I am using a 4 ohm 4 watt resistor in my setup, with the diodes to drop the voltage to the main uBitx board.

Please take the above with a grain of salt.  There may be errors, so verify.

Good luck with the build.

73
Evan
AC9TU

Murray Wills (ZL2IQ)
 

Thanks David – I see the 4.3 inch draws 250mA whereas the 5 inch is 410mA at 100% brightness.

 

I am going to try one of these later in the week (easier and cheaper than making) https://www.jaycar.co.nz/arduino-compatible-dc-voltage-regulator/p/XC4514 and will report back.

 

73

Murray ZL2IQ

 

From: BITX20@groups.io <BITX20@groups.io> On Behalf Of David Posthuma
Sent: Tuesday, 6 August 2019 11:11 AM
To: bitx20@groups.io; bitx20@groups.io
Subject: Re: [BITX20] V5.1 and Nextion 5”

 

I used a 4.3-inch Nextion screen with no problems.

 

David Posthuma

WD8PUO

 

 


From: bitx20@groups.io on behalf of Murray Wills (ZL2IQ) <murray@...>
Sent: Monday, August 5, 2019 6:27 PM
To: bitx20@groups.io
Subject: Re: [BITX20] V5.1 and Nextion 5”

 

Thank you Evan for the time you have taken to help me out.

73 Murray ZL2IQ

 

From: BITX20@groups.io <BITX20@groups.io> On Behalf Of Evan Hand
Sent: Monday, 5 August 2019 11:11 PM
To: BITX20@groups.io
Subject: Re: [BITX20] V5.1 and Nextion 5”

 

Murray,

What Mike is saying is that the 5" screen may be too much for the 7805 5 volt regulator in the Raduino that comes with the uBitx.  There are a number of options, everything from modifying the Raduino regulator circuit, to simply adding another 7805 5 volt dc regulator. 

Background:
The 13.8 volt power supply is much more than the uBitx needs.  The 13.8 volts is good for the finals, however the rest of the board prefers the specified 12 volts.  That is why there are two power connections on the uBitx board.  The 7805 5 volt regulator on the Raduino runs off of the uBitx board supply, not the finals supply.  As currently connected it needs to drop that 13.8 volts to 5 volts.  The difference is dissipated as heat by the regulator.  The amount of heat  depends on the current draw through it. The recommended power supply for the display by Nextion is 5 volts at 1 amp.  Much more than the stock Raduino setup can provide.  

Here is the Nextion spec sheet:
https://nextion.itead.cc/datasheets/nx8048k050/ 

Suggestion:
Based on the current requirements I would suggest that you add another, separate 5 volt power for the Nextion display. This can be based on a 7806 type of regulator like one that is in the Raduino, however it will need a dropping resistor, heat sink, and the appropriate filter capacitors to work.  Another option is to by an assembled 12 volt to 5 volt reducer.  The watch out here is that it could generate noise as most are pulsed based circuits.

Here is an example datasheet for the 7805.
  https://www.sparkfun.com/datasheets/Components/LM7805.pdf

See figure 1 on page 7.  It gives typical input and output capacitor values, though does not cover a dropping resistor. 

Since the input is relatively high compared to the minimum required, and the power dissipation is dependent on the voltage drop times the current (nominal 13.8 - 5 = 8.8 volts times the max current of 1 amp = 8.8 watts).  Much higher than the design dissipation even with a heat sink.  Adding a voltage dropping resistor to get the dissipation lower is suggested.  The minimum specified input voltage is 7 volts.  I would use 8 volts to account for any variations in the input supply.  That means we need to drop the 13.8 volts to 8 volts with a resistor at the current draw of the specified 1 amp.  For this I would use a 4 or 5 ohm power resistor rated for 4 or 5 watts respectively.  Since this is the DC part of the radio, wire wound works well. The actual value of resistor would be 5.8 ohms and 6 watts.  You can go lower in value, just means more heat to be dissipated by the regulator, but do not go higher as at some point the input voltage may drop below minimum.

You will need to add a heat sink on the regulator.  This can be the case if it is aluminum, and you install the appropriate insulators for the mounting.  I would go with a separate heat sink similar to the one on the finals.

Another suggestion is to put a voltage drop between the 13.8 volt supply and the uBitx board.  This involves separating the red and brown power supply wires (per the supplied connector).   To that end I would recommend adding 2 4n4000 series diodes to drop the 13.8 volts to 12 volts to the RED wire.  4n4000 series diodes are rated for only 1 amp, so you will need to separate the finals supply and connect it directly to the 13.8 volt source.  If you do this modification as well, will need to go back and recalculate the voltage and resistor values for the Nextion display above.  I am using a 4 ohm 4 watt resistor in my setup, with the diodes to drop the voltage to the main uBitx board.

Please take the above with a grain of salt.  There may be errors, so verify.

Good luck with the build.

73
Evan
AC9TU

Ian Reeve
 

If you have a T03 heatsink in your bits store,use a higher rated T03 pinout 5 v regulator.You will need to insulate the device from the Heatsinks but that will be a solution to the power demands of a larger nextion.


From: BITX20@groups.io <BITX20@groups.io> on behalf of Murray Wills (ZL2IQ) <murray@...>
Sent: Tuesday, August 6, 2019 12:17:50 AM
To: BITX20@groups.io <BITX20@groups.io>
Subject: Re: [BITX20] V5.1 and Nextion 5”
 

Thanks David – I see the 4.3 inch draws 250mA whereas the 5 inch is 410mA at 100% brightness.

 

I am going to try one of these later in the week (easier and cheaper than making) https://www.jaycar.co.nz/arduino-compatible-dc-voltage-regulator/p/XC4514 and will report back.

 

73

Murray ZL2IQ

 

From: BITX20@groups.io <BITX20@groups.io> On Behalf Of David Posthuma
Sent: Tuesday, 6 August 2019 11:11 AM
To: bitx20@groups.io; bitx20@groups.io
Subject: Re: [BITX20] V5.1 and Nextion 5”

 

I used a 4.3-inch Nextion screen with no problems.

 

David Posthuma

WD8PUO

 

 


From: bitx20@groups.io on behalf of Murray Wills (ZL2IQ) <murray@...>
Sent: Monday, August 5, 2019 6:27 PM
To: bitx20@groups.io
Subject: Re: [BITX20] V5.1 and Nextion 5”

 

Thank you Evan for the time you have taken to help me out.

73 Murray ZL2IQ

 

From: BITX20@groups.io <BITX20@groups.io> On Behalf Of Evan Hand
Sent: Monday, 5 August 2019 11:11 PM
To: BITX20@groups.io
Subject: Re: [BITX20] V5.1 and Nextion 5”

 

Murray,

What Mike is saying is that the 5" screen may be too much for the 7805 5 volt regulator in the Raduino that comes with the uBitx.  There are a number of options, everything from modifying the Raduino regulator circuit, to simply adding another 7805 5 volt dc regulator. 

Background:
The 13.8 volt power supply is much more than the uBitx needs.  The 13.8 volts is good for the finals, however the rest of the board prefers the specified 12 volts.  That is why there are two power connections on the uBitx board.  The 7805 5 volt regulator on the Raduino runs off of the uBitx board supply, not the finals supply.  As currently connected it needs to drop that 13.8 volts to 5 volts.  The difference is dissipated as heat by the regulator.  The amount of heat  depends on the current draw through it. The recommended power supply for the display by Nextion is 5 volts at 1 amp.  Much more than the stock Raduino setup can provide.  

Here is the Nextion spec sheet:
https://nextion.itead.cc/datasheets/nx8048k050/ 

Suggestion:
Based on the current requirements I would suggest that you add another, separate 5 volt power for the Nextion display. This can be based on a 7806 type of regulator like one that is in the Raduino, however it will need a dropping resistor, heat sink, and the appropriate filter capacitors to work.  Another option is to by an assembled 12 volt to 5 volt reducer.  The watch out here is that it could generate noise as most are pulsed based circuits.

Here is an example datasheet for the 7805.
  https://www.sparkfun.com/datasheets/Components/LM7805.pdf

See figure 1 on page 7.  It gives typical input and output capacitor values, though does not cover a dropping resistor. 

Since the input is relatively high compared to the minimum required, and the power dissipation is dependent on the voltage drop times the current (nominal 13.8 - 5 = 8.8 volts times the max current of 1 amp = 8.8 watts).  Much higher than the design dissipation even with a heat sink.  Adding a voltage dropping resistor to get the dissipation lower is suggested.  The minimum specified input voltage is 7 volts.  I would use 8 volts to account for any variations in the input supply.  That means we need to drop the 13.8 volts to 8 volts with a resistor at the current draw of the specified 1 amp.  For this I would use a 4 or 5 ohm power resistor rated for 4 or 5 watts respectively.  Since this is the DC part of the radio, wire wound works well. The actual value of resistor would be 5.8 ohms and 6 watts.  You can go lower in value, just means more heat to be dissipated by the regulator, but do not go higher as at some point the input voltage may drop below minimum.

You will need to add a heat sink on the regulator.  This can be the case if it is aluminum, and you install the appropriate insulators for the mounting.  I would go with a separate heat sink similar to the one on the finals.

Another suggestion is to put a voltage drop between the 13.8 volt supply and the uBitx board.  This involves separating the red and brown power supply wires (per the supplied connector).   To that end I would recommend adding 2 4n4000 series diodes to drop the 13.8 volts to 12 volts to the RED wire.  4n4000 series diodes are rated for only 1 amp, so you will need to separate the finals supply and connect it directly to the 13.8 volt source.  If you do this modification as well, will need to go back and recalculate the voltage and resistor values for the Nextion display above.  I am using a 4 ohm 4 watt resistor in my setup, with the diodes to drop the voltage to the main uBitx board.

Please take the above with a grain of salt.  There may be errors, so verify.

Good luck with the build.

73
Evan
AC9TU

MVS Sarma
 

In fact we get 78T05  a 3amp TO220 device  very cheap. I  had ordered for few on Aliexpress for personàl use.

Managing TO3  is little dìffìcult compared to TO220.

On Tue, 6 Aug 2019, 12:15 pm Ian Reeve, <ian.radioworkshop@...> wrote:
If you have a T03 heatsink in your bits store,use a higher rated T03 pinout 5 v regulator.You will need to insulate the device from the Heatsinks but that will be a solution to the power demands of a larger nextion.


From: BITX20@groups.io <BITX20@groups.io> on behalf of Murray Wills (ZL2IQ) <murray@...>
Sent: Tuesday, August 6, 2019 12:17:50 AM
To: BITX20@groups.io <BITX20@groups.io>
Subject: Re: [BITX20] V5.1 and Nextion 5”
 

Thanks David – I see the 4.3 inch draws 250mA whereas the 5 inch is 410mA at 100% brightness.

 

I am going to try one of these later in the week (easier and cheaper than making) https://www.jaycar.co.nz/arduino-compatible-dc-voltage-regulator/p/XC4514 and will report back.

 

73

Murray ZL2IQ

 

From: BITX20@groups.io <BITX20@groups.io> On Behalf Of David Posthuma
Sent: Tuesday, 6 August 2019 11:11 AM
To: bitx20@groups.io; bitx20@groups.io
Subject: Re: [BITX20] V5.1 and Nextion 5”

 

I used a 4.3-inch Nextion screen with no problems.

 

David Posthuma

WD8PUO

 

 


From: bitx20@groups.io on behalf of Murray Wills (ZL2IQ) <murray@...>
Sent: Monday, August 5, 2019 6:27 PM
To: bitx20@groups.io
Subject: Re: [BITX20] V5.1 and Nextion 5”

 

Thank you Evan for the time you have taken to help me out.

73 Murray ZL2IQ

 

From: BITX20@groups.io <BITX20@groups.io> On Behalf Of Evan Hand
Sent: Monday, 5 August 2019 11:11 PM
To: BITX20@groups.io
Subject: Re: [BITX20] V5.1 and Nextion 5”

 

Murray,

What Mike is saying is that the 5" screen may be too much for the 7805 5 volt regulator in the Raduino that comes with the uBitx.  There are a number of options, everything from modifying the Raduino regulator circuit, to simply adding another 7805 5 volt dc regulator. 

Background:
The 13.8 volt power supply is much more than the uBitx needs.  The 13.8 volts is good for the finals, however the rest of the board prefers the specified 12 volts.  That is why there are two power connections on the uBitx board.  The 7805 5 volt regulator on the Raduino runs off of the uBitx board supply, not the finals supply.  As currently connected it needs to drop that 13.8 volts to 5 volts.  The difference is dissipated as heat by the regulator.  The amount of heat  depends on the current draw through it. The recommended power supply for the display by Nextion is 5 volts at 1 amp.  Much more than the stock Raduino setup can provide.  

Here is the Nextion spec sheet:
https://nextion.itead.cc/datasheets/nx8048k050/ 

Suggestion:
Based on the current requirements I would suggest that you add another, separate 5 volt power for the Nextion display. This can be based on a 7806 type of regulator like one that is in the Raduino, however it will need a dropping resistor, heat sink, and the appropriate filter capacitors to work.  Another option is to by an assembled 12 volt to 5 volt reducer.  The watch out here is that it could generate noise as most are pulsed based circuits.

Here is an example datasheet for the 7805.
  https://www.sparkfun.com/datasheets/Components/LM7805.pdf

See figure 1 on page 7.  It gives typical input and output capacitor values, though does not cover a dropping resistor. 

Since the input is relatively high compared to the minimum required, and the power dissipation is dependent on the voltage drop times the current (nominal 13.8 - 5 = 8.8 volts times the max current of 1 amp = 8.8 watts).  Much higher than the design dissipation even with a heat sink.  Adding a voltage dropping resistor to get the dissipation lower is suggested.  The minimum specified input voltage is 7 volts.  I would use 8 volts to account for any variations in the input supply.  That means we need to drop the 13.8 volts to 8 volts with a resistor at the current draw of the specified 1 amp.  For this I would use a 4 or 5 ohm power resistor rated for 4 or 5 watts respectively.  Since this is the DC part of the radio, wire wound works well. The actual value of resistor would be 5.8 ohms and 6 watts.  You can go lower in value, just means more heat to be dissipated by the regulator, but do not go higher as at some point the input voltage may drop below minimum.

You will need to add a heat sink on the regulator.  This can be the case if it is aluminum, and you install the appropriate insulators for the mounting.  I would go with a separate heat sink similar to the one on the finals.

Another suggestion is to put a voltage drop between the 13.8 volt supply and the uBitx board.  This involves separating the red and brown power supply wires (per the supplied connector).   To that end I would recommend adding 2 4n4000 series diodes to drop the 13.8 volts to 12 volts to the RED wire.  4n4000 series diodes are rated for only 1 amp, so you will need to separate the finals supply and connect it directly to the 13.8 volt source.  If you do this modification as well, will need to go back and recalculate the voltage and resistor values for the Nextion display above.  I am using a 4 ohm 4 watt resistor in my setup, with the diodes to drop the voltage to the main uBitx board.

Please take the above with a grain of salt.  There may be errors, so verify.

Good luck with the build.

73
Evan
AC9TU

Evan Hand
 

I like MVS Sama's solution.  A simple parts swap of the existing 7805 for the 78T05 with heat sink and you do not need to worry about resistors or adding a second regulator.

Thank-you MVS Sama!

Evan
AC9TU

Murray Wills (ZL2IQ)
 

An elegant solution. Thanks Murray




On Tue, Aug 6, 2019 at 10:33 PM +1200, "Evan Hand" <elhandjr@...> wrote:

I like MVS Sama's solution.  A simple parts swap of the existing 7805 for the 78T05 with heat sink and you do not need to worry about resistors or adding a second regulator.

Thank-you MVS Sama!

Evan
AC9TU

Ian Reeve
 

A excellent solution,I was just giving an example that I would use from my junk box.I have rescued loads of Heatsinks of all sorts of shapes and sizes to I tend to find the Heatsinks and then match the holes to a suitable regulator.


From: BITX20@groups.io <BITX20@groups.io> on behalf of Murray Wills (ZL2IQ) <murray@...>
Sent: Tuesday, August 6, 2019 11:50:27 AM
To: bitx20@groups.io <bitx20@groups.io>; bitx20@groups.io <bitx20@groups.io>
Subject: Re: [BITX20] V5.1 and Nextion 5”
 
An elegant solution. Thanks Murray




On Tue, Aug 6, 2019 at 10:33 PM +1200, "Evan Hand" <elhandjr@...> wrote:

I like MVS Sama's solution.  A simple parts swap of the existing 7805 for the 78T05 with heat sink and you do not need to worry about resistors or adding a second regulator.

Thank-you MVS Sama!

Evan
AC9TU